* [PATCH v10 01/16] scripts/spelling: Add a few more typos
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 02/16] mm/page_ext: Export lookup_page_ext() to GPL modules SeongJae Park
` (14 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds typos found from DAMON patchset.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
scripts/spelling.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/scripts/spelling.txt b/scripts/spelling.txt
index ffa838f3a2b5..a8214d8e8e4b 100644
--- a/scripts/spelling.txt
+++ b/scripts/spelling.txt
@@ -59,6 +59,7 @@ actualy||actually
acumulating||accumulating
acumulative||accumulative
acumulator||accumulator
+acutally||actually
adapater||adapter
addional||additional
additionaly||additionally
@@ -245,6 +246,7 @@ calescing||coalescing
calle||called
callibration||calibration
callled||called
+callser||caller
calucate||calculate
calulate||calculate
cancelation||cancellation
@@ -664,6 +666,7 @@ hanlde||handle
hanled||handled
happend||happened
harware||hardware
+havind||having
heirarchically||hierarchically
helpfull||helpful
hexdecimal||hexadecimal
@@ -835,6 +838,7 @@ logile||logfile
loobpack||loopback
loosing||losing
losted||lost
+maangement||management
machinary||machinery
maibox||mailbox
maintainance||maintenance
@@ -999,6 +1003,7 @@ partiton||partition
pased||passed
passin||passing
pathes||paths
+pattrns||patterns
pecularities||peculiarities
peformance||performance
peforming||performing
@@ -1238,6 +1243,7 @@ shoule||should
shrinked||shrunk
siginificantly||significantly
signabl||signal
+significanly||significantly
similary||similarly
similiar||similar
simlar||similar
@@ -1352,6 +1358,7 @@ thead||thread
therfore||therefore
thier||their
threds||threads
+threee||three
threshhold||threshold
thresold||threshold
throught||through
@@ -1391,6 +1398,7 @@ tyep||type
udpate||update
uesd||used
uknown||unknown
+usccess||success
usupported||unsupported
uncommited||uncommitted
unconditionaly||unconditionally
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 02/16] mm/page_ext: Export lookup_page_ext() to GPL modules
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
2020-05-05 11:08 ` [PATCH v10 01/16] scripts/spelling: Add a few more typos SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 03/16] mm: Introduce Data Access MONitor (DAMON) SeongJae Park
` (13 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit exports 'lookup_page_ext()' to GPL modules. This will be
used by DAMON.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
mm/page_ext.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 4ade843ff588..71169b45bba9 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -131,6 +131,7 @@ struct page_ext *lookup_page_ext(const struct page *page)
MAX_ORDER_NR_PAGES);
return get_entry(base, index);
}
+EXPORT_SYMBOL_GPL(lookup_page_ext);
static int __init alloc_node_page_ext(int nid)
{
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 03/16] mm: Introduce Data Access MONitor (DAMON)
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
2020-05-05 11:08 ` [PATCH v10 01/16] scripts/spelling: Add a few more typos SeongJae Park
2020-05-05 11:08 ` [PATCH v10 02/16] mm/page_ext: Export lookup_page_ext() to GPL modules SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 04/16] mm/damon: Implement region based sampling SeongJae Park
` (12 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit introduces a kernel module named DAMON. Note that this
commit is implementing only the stub for the module load/unload, basic
data structures, and simple manipulation functions of the structures to
keep the size of commit small. The core mechanisms of DAMON will be
implemented one by one by following commits.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 36 +++++++++
mm/Kconfig | 12 +++
mm/Makefile | 1 +
mm/damon.c | 173 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 222 insertions(+)
create mode 100644 include/linux/damon.h
create mode 100644 mm/damon.c
diff --git a/include/linux/damon.h b/include/linux/damon.h
new file mode 100644
index 000000000000..19f411d36c0d
--- /dev/null
+++ b/include/linux/damon.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DAMON api
+ *
+ * Copyright 2019-2020 Amazon.com, Inc. or its affiliates.
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#ifndef _DAMON_H_
+#define _DAMON_H_
+
+#include <linux/random.h>
+#include <linux/types.h>
+
+/* Represents a monitoring target region of [vm_start, vm_end) */
+struct damon_region {
+ unsigned long vm_start;
+ unsigned long vm_end;
+ unsigned long sampling_addr;
+ unsigned int nr_accesses;
+ struct list_head list;
+};
+
+/* Represents a monitoring target task */
+struct damon_task {
+ int pid;
+ struct list_head regions_list;
+ struct list_head list;
+};
+
+struct damon_ctx {
+ struct list_head tasks_list; /* 'damon_task' objects */
+};
+
+#endif
diff --git a/mm/Kconfig b/mm/Kconfig
index ab80933be65f..9ea49633a6df 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -739,4 +739,16 @@ config ARCH_HAS_HUGEPD
config MAPPING_DIRTY_HELPERS
bool
+config DAMON
+ tristate "Data Access Monitor"
+ depends on MMU
+ help
+ Provides data access monitoring.
+
+ DAMON is a kernel module that allows users to monitor the actual
+ memory access pattern of specific user-space processes. It aims to
+ be 1) accurate enough to be useful for performance-centric domains,
+ and 2) sufficiently light-weight so that it can be applied online.
+ If unsure, say N.
+
endmenu
diff --git a/mm/Makefile b/mm/Makefile
index 272e66039e70..5346314edee6 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -110,3 +110,4 @@ obj-$(CONFIG_HMM_MIRROR) += hmm.o
obj-$(CONFIG_MEMFD_CREATE) += memfd.o
obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o
obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
+obj-$(CONFIG_DAMON) += damon.o
diff --git a/mm/damon.c b/mm/damon.c
new file mode 100644
index 000000000000..e319c1e19f3d
--- /dev/null
+++ b/mm/damon.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Data Access Monitor
+ *
+ * Copyright 2019-2020 Amazon.com, Inc. or its affiliates.
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#define pr_fmt(fmt) "damon: " fmt
+
+#include <linux/damon.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define damon_get_task_struct(t) \
+ (get_pid_task(find_vpid(t->pid), PIDTYPE_PID))
+
+#define damon_next_region(r) \
+ (container_of(r->list.next, struct damon_region, list))
+
+#define damon_prev_region(r) \
+ (container_of(r->list.prev, struct damon_region, list))
+
+#define damon_for_each_region(r, t) \
+ list_for_each_entry(r, &t->regions_list, list)
+
+#define damon_for_each_region_safe(r, next, t) \
+ list_for_each_entry_safe(r, next, &t->regions_list, list)
+
+#define damon_for_each_task(ctx, t) \
+ list_for_each_entry(t, &(ctx)->tasks_list, list)
+
+#define damon_for_each_task_safe(ctx, t, next) \
+ list_for_each_entry_safe(t, next, &(ctx)->tasks_list, list)
+
+/* Get a random number in [l, r) */
+#define damon_rand(l, r) (l + prandom_u32() % (r - l))
+
+/*
+ * Construct a damon_region struct
+ *
+ * Returns the pointer to the new struct if success, or NULL otherwise
+ */
+static struct damon_region *damon_new_region(struct damon_ctx *ctx,
+ unsigned long vm_start, unsigned long vm_end)
+{
+ struct damon_region *region;
+
+ region = kmalloc(sizeof(*region), GFP_KERNEL);
+ if (!region)
+ return NULL;
+
+ region->vm_start = vm_start;
+ region->vm_end = vm_end;
+ region->nr_accesses = 0;
+ INIT_LIST_HEAD(®ion->list);
+
+ return region;
+}
+
+/*
+ * Add a region between two other regions
+ */
+static inline void damon_insert_region(struct damon_region *r,
+ struct damon_region *prev, struct damon_region *next)
+{
+ __list_add(&r->list, &prev->list, &next->list);
+}
+
+static void damon_add_region(struct damon_region *r, struct damon_task *t)
+{
+ list_add_tail(&r->list, &t->regions_list);
+}
+
+static void damon_del_region(struct damon_region *r)
+{
+ list_del(&r->list);
+}
+
+static void damon_free_region(struct damon_region *r)
+{
+ kfree(r);
+}
+
+static void damon_destroy_region(struct damon_region *r)
+{
+ damon_del_region(r);
+ damon_free_region(r);
+}
+
+/*
+ * Construct a damon_task struct
+ *
+ * Returns the pointer to the new struct if success, or NULL otherwise
+ */
+static struct damon_task *damon_new_task(int pid)
+{
+ struct damon_task *t;
+
+ t = kmalloc(sizeof(*t), GFP_KERNEL);
+ if (!t)
+ return NULL;
+
+ t->pid = pid;
+ INIT_LIST_HEAD(&t->regions_list);
+
+ return t;
+}
+
+static void damon_add_task(struct damon_ctx *ctx, struct damon_task *t)
+{
+ list_add_tail(&t->list, &ctx->tasks_list);
+}
+
+static void damon_del_task(struct damon_task *t)
+{
+ list_del(&t->list);
+}
+
+static void damon_free_task(struct damon_task *t)
+{
+ struct damon_region *r, *next;
+
+ damon_for_each_region_safe(r, next, t)
+ damon_free_region(r);
+ kfree(t);
+}
+
+static void damon_destroy_task(struct damon_task *t)
+{
+ damon_del_task(t);
+ damon_free_task(t);
+}
+
+static unsigned int nr_damon_tasks(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+ unsigned int nr_tasks = 0;
+
+ damon_for_each_task(ctx, t)
+ nr_tasks++;
+
+ return nr_tasks;
+}
+
+static unsigned int nr_damon_regions(struct damon_task *t)
+{
+ struct damon_region *r;
+ unsigned int nr_regions = 0;
+
+ damon_for_each_region(r, t)
+ nr_regions++;
+
+ return nr_regions;
+}
+
+static int __init damon_init(void)
+{
+ return 0;
+}
+
+static void __exit damon_exit(void)
+{
+}
+
+module_init(damon_init);
+module_exit(damon_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("SeongJae Park <sjpark@amazon.de>");
+MODULE_DESCRIPTION("DAMON: Data Access MONitor");
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 04/16] mm/damon: Implement region based sampling
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (2 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 03/16] mm: Introduce Data Access MONitor (DAMON) SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 05/16] mm/damon: Adaptively adjust regions SeongJae Park
` (11 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit implements DAMON's basic access check and region based
sampling mechanisms. This change would seems make no sense, mainly
because it is only a part of the DAMON's logics. Following two commits
will make more sense.
Basic Access Check
------------------
DAMON basically reports what pages are how frequently accessed. Note
that the frequency is not an absolute number of accesses, but a relative
frequency among the pages of the target workloads.
Users can control the resolution of the reports by setting two time
intervals, ``sampling interval`` and ``aggregation interval``. In
detail, DAMON checks access to each page per ``sampling interval``,
aggregates the results (counts the number of the accesses to each page),
and reports the aggregated results per ``aggregation interval``. For
the access check of each page, DAMON uses the Accessed bits of PTEs.
This is thus similar to common periodic access checks based access
tracking mechanisms, which overhead is increasing as the size of the
target process grows.
Region Based Sampling
---------------------
To avoid the unbounded increase of the overhead, DAMON groups a number
of adjacent pages that assumed to have same access frequencies into a
region. As long as the assumption (pages in a region have same access
frequencies) is kept, only one page in the region is required to be
checked. Thus, for each ``sampling interval``, DAMON randomly picks one
page in each region and clears its Accessed bit. After one more
``sampling interval``, DAMON reads the Accessed bit of the page and
increases the access frequency of the region if the bit has set
meanwhile. Therefore, the monitoring overhead is controllable by
setting the number of regions.
Nonetheless, this scheme cannot preserve the quality of the output if
the assumption is not kept. Following commit will introduce how we can
make the guarantee with best effort.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 25 ++
mm/damon.c | 597 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 622 insertions(+)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 19f411d36c0d..558dd6ae0afa 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -11,6 +11,8 @@
#define _DAMON_H_
#include <linux/random.h>
+#include <linux/mutex.h>
+#include <linux/time64.h>
#include <linux/types.h>
/* Represents a monitoring target region of [vm_start, vm_end) */
@@ -29,8 +31,31 @@ struct damon_task {
struct list_head list;
};
+/*
+ * For each 'sample_interval', DAMON checks whether each region is accessed or
+ * not. It aggregates and keeps the access information (number of accesses to
+ * each region) for each 'aggr_interval' time.
+ *
+ * All time intervals are in micro-seconds.
+ */
struct damon_ctx {
+ unsigned long sample_interval;
+ unsigned long aggr_interval;
+ unsigned long min_nr_regions;
+
+ struct timespec64 last_aggregation;
+
+ struct task_struct *kdamond;
+ bool kdamond_stop;
+ struct mutex kdamond_lock;
+
struct list_head tasks_list; /* 'damon_task' objects */
};
+int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids);
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+ unsigned long aggr_int, unsigned long min_nr_reg);
+int damon_start(struct damon_ctx *ctx);
+int damon_stop(struct damon_ctx *ctx);
+
#endif
diff --git a/mm/damon.c b/mm/damon.c
index e319c1e19f3d..9c9aa18e846a 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -10,10 +10,19 @@
#define pr_fmt(fmt) "damon: " fmt
#include <linux/damon.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/page_idle.h>
+#include <linux/random.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/task.h>
#include <linux/slab.h>
+/* Minimal region size. Every damon_region is aligned by this. */
+#define MIN_REGION PAGE_SIZE
+
#define damon_get_task_struct(t) \
(get_pid_task(find_vpid(t->pid), PIDTYPE_PID))
@@ -156,6 +165,594 @@ static unsigned int nr_damon_regions(struct damon_task *t)
return nr_regions;
}
+/*
+ * Get the mm_struct of the given task
+ *
+ * Caller _must_ put the mm_struct after use, unless it is NULL.
+ *
+ * Returns the mm_struct of the task on success, NULL on failure
+ */
+static struct mm_struct *damon_get_mm(struct damon_task *t)
+{
+ struct task_struct *task;
+ struct mm_struct *mm;
+
+ task = damon_get_task_struct(t);
+ if (!task)
+ return NULL;
+
+ mm = get_task_mm(task);
+ put_task_struct(task);
+ return mm;
+}
+
+/*
+ * Size-evenly split a region into 'nr_pieces' small regions
+ *
+ * Returns 0 on success, or negative error code otherwise.
+ */
+static int damon_split_region_evenly(struct damon_ctx *ctx,
+ struct damon_region *r, unsigned int nr_pieces)
+{
+ unsigned long sz_orig, sz_piece, orig_end;
+ struct damon_region *n = NULL, *next;
+ unsigned long start;
+
+ if (!r || !nr_pieces)
+ return -EINVAL;
+
+ orig_end = r->vm_end;
+ sz_orig = r->vm_end - r->vm_start;
+ sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, MIN_REGION);
+
+ if (!sz_piece)
+ return -EINVAL;
+
+ r->vm_end = r->vm_start + sz_piece;
+ next = damon_next_region(r);
+ for (start = r->vm_end; start + sz_piece <= orig_end;
+ start += sz_piece) {
+ n = damon_new_region(ctx, start, start + sz_piece);
+ if (!n)
+ return -ENOMEM;
+ damon_insert_region(n, r, next);
+ r = n;
+ }
+ /* complement last region for possible rounding error */
+ if (n)
+ n->vm_end = orig_end;
+
+ return 0;
+}
+
+struct region {
+ unsigned long start;
+ unsigned long end;
+};
+
+static unsigned long sz_region(struct region *r)
+{
+ return r->end - r->start;
+}
+
+static void swap_regions(struct region *r1, struct region *r2)
+{
+ struct region tmp;
+
+ tmp = *r1;
+ *r1 = *r2;
+ *r2 = tmp;
+}
+
+/*
+ * Find three regions separated by two biggest unmapped regions
+ *
+ * vma the head vma of the target address space
+ * regions an array of three 'struct region's that results will be saved
+ *
+ * This function receives an address space and finds three regions in it which
+ * separated by the two biggest unmapped regions in the space. Please refer to
+ * below comments of 'damon_init_regions_of()' function to know why this is
+ * necessary.
+ *
+ * Returns 0 if success, or negative error code otherwise.
+ */
+static int damon_three_regions_in_vmas(struct vm_area_struct *vma,
+ struct region regions[3])
+{
+ struct region gap = {0}, first_gap = {0}, second_gap = {0};
+ struct vm_area_struct *last_vma = NULL;
+ unsigned long start = 0;
+
+ /* Find two biggest gaps so that first_gap > second_gap > others */
+ for (; vma; vma = vma->vm_next) {
+ if (!last_vma) {
+ start = vma->vm_start;
+ last_vma = vma;
+ continue;
+ }
+ gap.start = last_vma->vm_end;
+ gap.end = vma->vm_start;
+ if (sz_region(&gap) > sz_region(&second_gap)) {
+ swap_regions(&gap, &second_gap);
+ if (sz_region(&second_gap) > sz_region(&first_gap))
+ swap_regions(&second_gap, &first_gap);
+ }
+ last_vma = vma;
+ }
+
+ if (!sz_region(&second_gap) || !sz_region(&first_gap))
+ return -EINVAL;
+
+ /* Sort the two biggest gaps by address */
+ if (first_gap.start > second_gap.start)
+ swap_regions(&first_gap, &second_gap);
+
+ /* Store the result */
+ regions[0].start = ALIGN(start, MIN_REGION);
+ regions[0].end = ALIGN(first_gap.start, MIN_REGION);
+ regions[1].start = ALIGN(first_gap.end, MIN_REGION);
+ regions[1].end = ALIGN(second_gap.start, MIN_REGION);
+ regions[2].start = ALIGN(second_gap.end, MIN_REGION);
+ regions[2].end = ALIGN(last_vma->vm_end, MIN_REGION);
+
+ return 0;
+}
+
+/*
+ * Get the three regions in the given task
+ *
+ * Returns 0 on success, negative error code otherwise.
+ */
+static int damon_three_regions_of(struct damon_task *t,
+ struct region regions[3])
+{
+ struct mm_struct *mm;
+ int rc;
+
+ mm = damon_get_mm(t);
+ if (!mm)
+ return -EINVAL;
+
+ down_read(&mm->mmap_sem);
+ rc = damon_three_regions_in_vmas(mm->mmap, regions);
+ up_read(&mm->mmap_sem);
+
+ mmput(mm);
+ return rc;
+}
+
+/*
+ * Initialize the monitoring target regions for the given task
+ *
+ * t the given target task
+ *
+ * Because only a number of small portions of the entire address space
+ * is actually mapped to the memory and accessed, monitoring the unmapped
+ * regions is wasteful. That said, because we can deal with small noises,
+ * tracking every mapping is not strictly required but could even incur a high
+ * overhead if the mapping frequently changes or the number of mappings is
+ * high. Nonetheless, this may seems very weird. DAMON's dynamic regions
+ * adjustment mechanism, which will be implemented with following commit will
+ * make this more sense.
+ *
+ * For the reason, we convert the complex mappings to three distinct regions
+ * that cover every mapped area of the address space. Also the two gaps
+ * between the three regions are the two biggest unmapped areas in the given
+ * address space. In detail, this function first identifies the start and the
+ * end of the mappings and the two biggest unmapped areas of the address space.
+ * Then, it constructs the three regions as below:
+ *
+ * [mappings[0]->start, big_two_unmapped_areas[0]->start)
+ * [big_two_unmapped_areas[0]->end, big_two_unmapped_areas[1]->start)
+ * [big_two_unmapped_areas[1]->end, mappings[nr_mappings - 1]->end)
+ *
+ * As usual memory map of processes is as below, the gap between the heap and
+ * the uppermost mmap()-ed region, and the gap between the lowermost mmap()-ed
+ * region and the stack will be two biggest unmapped regions. Because these
+ * gaps are exceptionally huge areas in usual address space, excluding these
+ * two biggest unmapped regions will be sufficient to make a trade-off.
+ *
+ * <heap>
+ * <BIG UNMAPPED REGION 1>
+ * <uppermost mmap()-ed region>
+ * (other mmap()-ed regions and small unmapped regions)
+ * <lowermost mmap()-ed region>
+ * <BIG UNMAPPED REGION 2>
+ * <stack>
+ */
+static void damon_init_regions_of(struct damon_ctx *c, struct damon_task *t)
+{
+ struct damon_region *r, *m = NULL;
+ struct region regions[3];
+ int i;
+
+ if (damon_three_regions_of(t, regions)) {
+ pr_err("Failed to get three regions of task %d\n", t->pid);
+ return;
+ }
+
+ /* Set the initial three regions of the task */
+ for (i = 0; i < 3; i++) {
+ r = damon_new_region(c, regions[i].start, regions[i].end);
+ if (!r) {
+ pr_err("%d'th init region creation failed\n", i);
+ return;
+ }
+ damon_add_region(r, t);
+ if (i == 1)
+ m = r;
+ }
+
+ /* Split the middle region into 'min_nr_regions - 2' regions */
+ if (damon_split_region_evenly(c, m, c->min_nr_regions - 2))
+ pr_warn("Init middle region failed to be split\n");
+}
+
+/* Initialize '->regions_list' of every task */
+static void kdamond_init_regions(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+
+ damon_for_each_task(ctx, t)
+ damon_init_regions_of(ctx, t);
+}
+
+static void damon_mkold(struct mm_struct *mm, unsigned long addr)
+{
+ pte_t *pte = NULL;
+ pmd_t *pmd = NULL;
+ spinlock_t *ptl;
+
+ if (follow_pte_pmd(mm, addr, NULL, &pte, &pmd, &ptl))
+ return;
+
+ if (pte) {
+ if (pte_young(*pte)) {
+ clear_page_idle(pte_page(*pte));
+ set_page_young(pte_page(*pte));
+ }
+ *pte = pte_mkold(*pte);
+ pte_unmap_unlock(pte, ptl);
+ return;
+ }
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ if (pmd_young(*pmd)) {
+ clear_page_idle(pmd_page(*pmd));
+ set_page_young(pmd_page(*pmd));
+ }
+ *pmd = pmd_mkold(*pmd);
+ spin_unlock(ptl);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+}
+
+static void damon_prepare_access_check(struct damon_ctx *ctx,
+ struct mm_struct *mm, struct damon_region *r)
+{
+ r->sampling_addr = damon_rand(r->vm_start, r->vm_end);
+
+ damon_mkold(mm, r->sampling_addr);
+}
+
+static void kdamond_prepare_access_checks(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+ struct mm_struct *mm;
+ struct damon_region *r;
+
+ damon_for_each_task(ctx, t) {
+ mm = damon_get_mm(t);
+ if (!mm)
+ continue;
+ damon_for_each_region(r, t)
+ damon_prepare_access_check(ctx, mm, r);
+ mmput(mm);
+ }
+}
+
+static bool damon_young(struct mm_struct *mm, unsigned long addr,
+ unsigned long *page_sz)
+{
+ pte_t *pte = NULL;
+ pmd_t *pmd = NULL;
+ spinlock_t *ptl;
+ bool young = false;
+
+ if (follow_pte_pmd(mm, addr, NULL, &pte, &pmd, &ptl))
+ return false;
+
+ *page_sz = PAGE_SIZE;
+ if (pte) {
+ young = pte_young(*pte);
+ pte_unmap_unlock(pte, ptl);
+ return young;
+ }
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ young = pmd_young(*pmd);
+ spin_unlock(ptl);
+ *page_sz = ((1UL) << HPAGE_PMD_SHIFT);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+ return young;
+}
+
+/*
+ * Check whether the region was accessed and prepare for next check
+ *
+ * mm 'mm_struct' for the given virtual address space
+ * r the region to be checked
+ */
+static void damon_check_access(struct damon_ctx *ctx,
+ struct mm_struct *mm, struct damon_region *r)
+{
+ static struct mm_struct *last_mm;
+ static unsigned long last_addr;
+ static unsigned long last_page_sz = PAGE_SIZE;
+ static bool last_accessed;
+
+ /* If the region is in the last checked page, reuse the result */
+ if (mm == last_mm && (ALIGN_DOWN(last_addr, last_page_sz) ==
+ ALIGN_DOWN(r->sampling_addr, last_page_sz))) {
+ if (last_accessed)
+ r->nr_accesses++;
+ return;
+ }
+
+ last_accessed = damon_young(mm, r->sampling_addr, &last_page_sz);
+ if (last_accessed)
+ r->nr_accesses++;
+
+ last_mm = mm;
+ last_addr = r->sampling_addr;
+}
+
+static void kdamond_check_accesses(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+ struct mm_struct *mm;
+ struct damon_region *r;
+
+ damon_for_each_task(ctx, t) {
+ mm = damon_get_mm(t);
+ if (!mm)
+ continue;
+ damon_for_each_region(r, t)
+ damon_check_access(ctx, mm, r);
+ mmput(mm);
+ }
+}
+
+/**
+ * damon_check_reset_time_interval() - Check if a time interval is elapsed.
+ * @baseline: the time to check whether the interval has elapsed since
+ * @interval: the time interval (microseconds)
+ *
+ * See whether the given time interval has passed since the given baseline
+ * time. If so, it also updates the baseline to current time for next check.
+ *
+ * Return: true if the time interval has passed, or false otherwise.
+ */
+static bool damon_check_reset_time_interval(struct timespec64 *baseline,
+ unsigned long interval)
+{
+ struct timespec64 now;
+
+ ktime_get_coarse_ts64(&now);
+ if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) <
+ interval * 1000)
+ return false;
+ *baseline = now;
+ return true;
+}
+
+/*
+ * Check whether it is time to flush the aggregated information
+ */
+static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx)
+{
+ return damon_check_reset_time_interval(&ctx->last_aggregation,
+ ctx->aggr_interval);
+}
+
+/*
+ * Reset the aggregated monitoring results
+ */
+static void kdamond_reset_aggregated(struct damon_ctx *c)
+{
+ struct damon_task *t;
+ struct damon_region *r;
+
+ damon_for_each_task(c, t) {
+ damon_for_each_region(r, t)
+ r->nr_accesses = 0;
+ }
+}
+
+/*
+ * Check whether current monitoring should be stopped
+ *
+ * The monitoring is stopped when either the user requested to stop, or all
+ * monitoring target tasks are dead.
+ *
+ * Returns true if need to stop current monitoring.
+ */
+static bool kdamond_need_stop(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+ struct task_struct *task;
+ bool stop;
+
+ mutex_lock(&ctx->kdamond_lock);
+ stop = ctx->kdamond_stop;
+ mutex_unlock(&ctx->kdamond_lock);
+ if (stop)
+ return true;
+
+ damon_for_each_task(ctx, t) {
+ task = damon_get_task_struct(t);
+ if (task) {
+ put_task_struct(task);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*
+ * The monitoring daemon that runs as a kernel thread
+ */
+static int kdamond_fn(void *data)
+{
+ struct damon_ctx *ctx = (struct damon_ctx *)data;
+ struct damon_task *t;
+ struct damon_region *r, *next;
+
+ pr_info("kdamond (%d) starts\n", ctx->kdamond->pid);
+ kdamond_init_regions(ctx);
+ while (!kdamond_need_stop(ctx)) {
+ kdamond_prepare_access_checks(ctx);
+
+ usleep_range(ctx->sample_interval, ctx->sample_interval + 1);
+
+ kdamond_check_accesses(ctx);
+
+ if (kdamond_aggregate_interval_passed(ctx))
+ kdamond_reset_aggregated(ctx);
+
+ }
+ damon_for_each_task(ctx, t) {
+ damon_for_each_region_safe(r, next, t)
+ damon_destroy_region(r);
+ }
+ pr_debug("kdamond (%d) finishes\n", ctx->kdamond->pid);
+ mutex_lock(&ctx->kdamond_lock);
+ ctx->kdamond = NULL;
+ mutex_unlock(&ctx->kdamond_lock);
+
+ do_exit(0);
+}
+
+/*
+ * Controller functions
+ */
+
+static bool damon_kdamond_running(struct damon_ctx *ctx)
+{
+ bool running;
+
+ mutex_lock(&ctx->kdamond_lock);
+ running = ctx->kdamond != NULL;
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return running;
+}
+
+/**
+ * damon_start() - Starts monitoring with given context.
+ * @ctx: monitoring context
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_start(struct damon_ctx *ctx)
+{
+ int err = -EBUSY;
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (!ctx->kdamond) {
+ err = 0;
+ ctx->kdamond_stop = false;
+ ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond");
+ if (IS_ERR(ctx->kdamond))
+ err = PTR_ERR(ctx->kdamond);
+ }
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return err;
+}
+
+/**
+ * damon_stop() - Stops monitoring of given context.
+ * @ctx: monitoring context
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_stop(struct damon_ctx *ctx)
+{
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond) {
+ ctx->kdamond_stop = true;
+ mutex_unlock(&ctx->kdamond_lock);
+ while (damon_kdamond_running(ctx))
+ usleep_range(ctx->sample_interval,
+ ctx->sample_interval * 2);
+ return 0;
+ }
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return -EPERM;
+}
+
+/**
+ * damon_set_pids() - Set monitoring target processes.
+ * @ctx: monitoring context
+ * @pids: array of target processes pids
+ * @nr_pids: number of entries in @pids
+ *
+ * This function should not be called while the kdamond is running.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids)
+{
+ ssize_t i;
+ struct damon_task *t, *next;
+
+ damon_for_each_task_safe(ctx, t, next)
+ damon_destroy_task(t);
+
+ for (i = 0; i < nr_pids; i++) {
+ t = damon_new_task(pids[i]);
+ if (!t) {
+ pr_err("Failed to alloc damon_task\n");
+ return -ENOMEM;
+ }
+ damon_add_task(ctx, t);
+ }
+
+ return 0;
+}
+
+/**
+ * damon_set_attrs() - Set attributes for the monitoring.
+ * @ctx: monitoring context
+ * @sample_int: time interval between samplings
+ * @aggr_int: time interval between aggregations
+ * @min_nr_reg: minimal number of regions
+ *
+ * This function should not be called while the kdamond is running.
+ * Every time interval is in micro-seconds.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+ unsigned long aggr_int, unsigned long min_nr_reg)
+{
+ if (min_nr_reg < 3) {
+ pr_err("min_nr_regions (%lu) must be at least 3\n",
+ min_nr_reg);
+ return -EINVAL;
+ }
+
+ ctx->sample_interval = sample_int;
+ ctx->aggr_interval = aggr_int;
+ ctx->min_nr_regions = min_nr_reg;
+
+ return 0;
+}
+
static int __init damon_init(void)
{
return 0;
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 05/16] mm/damon: Adaptively adjust regions
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (3 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 04/16] mm/damon: Implement region based sampling SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 06/16] mm/damon: Split regions into 4 subregions if possible SeongJae Park
` (10 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
At the beginning of the monitoring, DAMON constructs the initial regions
by evenly splitting the memory mapped address space of the process into
the user-specified minimal number of regions. In this initial state,
the assumption of the regions (pages in same region have similar access
frequencies) is normally not kept and thus the monitoring quality could
be low. To keep the assumption as much as possible, DAMON adaptively
merges and splits each region.
For each ``aggregation interval``, it compares the access frequencies of
adjacent regions and merges those if the frequency difference is small.
Then, after it reports and clears the aggregated access frequency of
each region, it splits each region into two regions if the total number
of regions is smaller than the half of the user-specified maximum number
of regions.
In this way, DAMON provides its best-effort quality and minimal overhead
while keeping the bounds users set for their trade-off.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 6 +-
mm/damon.c | 158 +++++++++++++++++++++++++++++++++++++++---
2 files changed, 152 insertions(+), 12 deletions(-)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 558dd6ae0afa..f1c3f491fc50 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -42,6 +42,7 @@ struct damon_ctx {
unsigned long sample_interval;
unsigned long aggr_interval;
unsigned long min_nr_regions;
+ unsigned long max_nr_regions;
struct timespec64 last_aggregation;
@@ -53,8 +54,9 @@ struct damon_ctx {
};
int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids);
-int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
- unsigned long aggr_int, unsigned long min_nr_reg);
+int damon_set_attrs(struct damon_ctx *ctx,
+ unsigned long sample_int, unsigned long aggr_int,
+ unsigned long min_nr_reg, unsigned long max_nr_reg);
int damon_start(struct damon_ctx *ctx);
int damon_stop(struct damon_ctx *ctx);
diff --git a/mm/damon.c b/mm/damon.c
index 9c9aa18e846a..cec946197e13 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -332,9 +332,12 @@ static int damon_three_regions_of(struct damon_task *t,
* regions is wasteful. That said, because we can deal with small noises,
* tracking every mapping is not strictly required but could even incur a high
* overhead if the mapping frequently changes or the number of mappings is
- * high. Nonetheless, this may seems very weird. DAMON's dynamic regions
- * adjustment mechanism, which will be implemented with following commit will
- * make this more sense.
+ * high. The adaptive regions adjustment mechanism will further help to deal
+ * with the noise by simply identifying the unmapped areas as a region that
+ * has no access. Moreover, applying the real mappings that would have many
+ * unmapped areas inside will make the adaptive mechanism quite complex. That
+ * said, too huge unmapped areas inside the monitoring target should be removed
+ * to not take the time for the adaptive mechanism.
*
* For the reason, we convert the complex mappings to three distinct regions
* that cover every mapped area of the address space. Also the two gaps
@@ -508,20 +511,25 @@ static void damon_check_access(struct damon_ctx *ctx,
last_addr = r->sampling_addr;
}
-static void kdamond_check_accesses(struct damon_ctx *ctx)
+static unsigned int kdamond_check_accesses(struct damon_ctx *ctx)
{
struct damon_task *t;
struct mm_struct *mm;
struct damon_region *r;
+ unsigned int max_nr_accesses = 0;
damon_for_each_task(ctx, t) {
mm = damon_get_mm(t);
if (!mm)
continue;
- damon_for_each_region(r, t)
+ damon_for_each_region(r, t) {
damon_check_access(ctx, mm, r);
+ max_nr_accesses = max(r->nr_accesses, max_nr_accesses);
+ }
+
mmput(mm);
}
+ return max_nr_accesses;
}
/**
@@ -570,6 +578,125 @@ static void kdamond_reset_aggregated(struct damon_ctx *c)
}
}
+#define sz_damon_region(r) (r->vm_end - r->vm_start)
+
+/*
+ * Merge two adjacent regions into one region
+ */
+static void damon_merge_two_regions(struct damon_region *l,
+ struct damon_region *r)
+{
+ l->nr_accesses = (l->nr_accesses * sz_damon_region(l) +
+ r->nr_accesses * sz_damon_region(r)) /
+ (sz_damon_region(l) + sz_damon_region(r));
+ l->vm_end = r->vm_end;
+ damon_destroy_region(r);
+}
+
+#define diff_of(a, b) (a > b ? a - b : b - a)
+
+/*
+ * Merge adjacent regions having similar access frequencies
+ *
+ * t task affected by merge operation
+ * thres '->nr_accesses' diff threshold for the merge
+ */
+static void damon_merge_regions_of(struct damon_task *t, unsigned int thres)
+{
+ struct damon_region *r, *prev = NULL, *next;
+
+ damon_for_each_region_safe(r, next, t) {
+ if (!prev || prev->vm_end != r->vm_start ||
+ diff_of(prev->nr_accesses, r->nr_accesses) > thres) {
+ prev = r;
+ continue;
+ }
+ damon_merge_two_regions(prev, r);
+ }
+}
+
+/*
+ * Merge adjacent regions having similar access frequencies
+ *
+ * threshold merge regions having nr_accesses diff larger than this
+ *
+ * This function merges monitoring target regions which are adjacent and their
+ * access frequencies are similar. This is for minimizing the monitoring
+ * overhead under the dynamically changeable access pattern. If a merge was
+ * unnecessarily made, later 'kdamond_split_regions()' will revert it.
+ */
+static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold)
+{
+ struct damon_task *t;
+
+ damon_for_each_task(c, t)
+ damon_merge_regions_of(t, threshold);
+}
+
+/*
+ * Split a region in two
+ *
+ * r the region to be split
+ * sz_r size of the first sub-region that will be made
+ */
+static void damon_split_region_at(struct damon_ctx *ctx,
+ struct damon_region *r, unsigned long sz_r)
+{
+ struct damon_region *new;
+
+ new = damon_new_region(ctx, r->vm_start + sz_r, r->vm_end);
+ r->vm_end = new->vm_start;
+
+ damon_insert_region(new, r, damon_next_region(r));
+}
+
+/* Split every region in the given task into two randomly-sized regions */
+static void damon_split_regions_of(struct damon_ctx *ctx, struct damon_task *t)
+{
+ struct damon_region *r, *next;
+ unsigned long sz_orig_region, sz_left_region;
+
+ damon_for_each_region_safe(r, next, t) {
+ sz_orig_region = r->vm_end - r->vm_start;
+
+ /*
+ * Randomly select size of left sub-region to be at least
+ * 10 percent and at most 90% of original region
+ */
+ sz_left_region = ALIGN_DOWN(damon_rand(1, 10) * sz_orig_region
+ / 10, MIN_REGION);
+ /* Do not allow blank region */
+ if (sz_left_region == 0 || sz_left_region >= sz_orig_region)
+ continue;
+
+ damon_split_region_at(ctx, r, sz_left_region);
+ }
+}
+
+/*
+ * splits every target region into two randomly-sized regions
+ *
+ * This function splits every target region into two random-sized regions if
+ * current total number of the regions is equal or smaller than half of the
+ * user-specified maximum number of regions. This is for maximizing the
+ * monitoring accuracy under the dynamically changeable access patterns. If a
+ * split was unnecessarily made, later 'kdamond_merge_regions()' will revert
+ * it.
+ */
+static void kdamond_split_regions(struct damon_ctx *ctx)
+{
+ struct damon_task *t;
+ unsigned int nr_regions = 0;
+
+ damon_for_each_task(ctx, t)
+ nr_regions += nr_damon_regions(t);
+ if (nr_regions > ctx->max_nr_regions / 2)
+ return;
+
+ damon_for_each_task(ctx, t)
+ damon_split_regions_of(ctx, t);
+}
+
/*
* Check whether current monitoring should be stopped
*
@@ -609,6 +736,7 @@ static int kdamond_fn(void *data)
struct damon_ctx *ctx = (struct damon_ctx *)data;
struct damon_task *t;
struct damon_region *r, *next;
+ unsigned int max_nr_accesses = 0;
pr_info("kdamond (%d) starts\n", ctx->kdamond->pid);
kdamond_init_regions(ctx);
@@ -617,11 +745,13 @@ static int kdamond_fn(void *data)
usleep_range(ctx->sample_interval, ctx->sample_interval + 1);
- kdamond_check_accesses(ctx);
+ max_nr_accesses = kdamond_check_accesses(ctx);
- if (kdamond_aggregate_interval_passed(ctx))
+ if (kdamond_aggregate_interval_passed(ctx)) {
+ kdamond_merge_regions(ctx, max_nr_accesses / 10);
kdamond_reset_aggregated(ctx);
-
+ kdamond_split_regions(ctx);
+ }
}
damon_for_each_task(ctx, t) {
damon_for_each_region_safe(r, next, t)
@@ -731,24 +861,32 @@ int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids)
* @sample_int: time interval between samplings
* @aggr_int: time interval between aggregations
* @min_nr_reg: minimal number of regions
+ * @max_nr_reg: maximum number of regions
*
* This function should not be called while the kdamond is running.
* Every time interval is in micro-seconds.
*
* Return: 0 on success, negative error code otherwise.
*/
-int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
- unsigned long aggr_int, unsigned long min_nr_reg)
+int damon_set_attrs(struct damon_ctx *ctx,
+ unsigned long sample_int, unsigned long aggr_int,
+ unsigned long min_nr_reg, unsigned long max_nr_reg)
{
if (min_nr_reg < 3) {
pr_err("min_nr_regions (%lu) must be at least 3\n",
min_nr_reg);
return -EINVAL;
}
+ if (min_nr_reg > max_nr_reg) {
+ pr_err("invalid nr_regions. min (%lu) > max (%lu)\n",
+ min_nr_reg, max_nr_reg);
+ return -EINVAL;
+ }
ctx->sample_interval = sample_int;
ctx->aggr_interval = aggr_int;
ctx->min_nr_regions = min_nr_reg;
+ ctx->max_nr_regions = max_nr_reg;
return 0;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 06/16] mm/damon: Split regions into 4 subregions if possible
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (4 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 05/16] mm/damon: Adaptively adjust regions SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-07 8:28 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 07/16] mm/damon: Apply dynamic memory mapping changes SeongJae Park
` (9 subsequent siblings)
15 siblings, 1 reply; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
Suppose that there are a very wide and cold region and a hot region, and
both regions are identified by DAMON. And then, the middle small region
inside the very wide and cold region becomes hot. DAMON will not be
able to identify this new region because the adaptive regions adjustment
mechanism splits each region to only two subregions.
This commit modifies the logic to split each region to 4 subregions if
possible so that such problematic region can eventually identified.
Suggested-by: James Cameron <Jonathan.Cameron@Huawei.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
mm/damon.c | 44 +++++++++++++++++++++++++++-----------------
1 file changed, 27 insertions(+), 17 deletions(-)
diff --git a/mm/damon.c b/mm/damon.c
index cec946197e13..342f905927a0 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -650,26 +650,32 @@ static void damon_split_region_at(struct damon_ctx *ctx,
damon_insert_region(new, r, damon_next_region(r));
}
-/* Split every region in the given task into two randomly-sized regions */
-static void damon_split_regions_of(struct damon_ctx *ctx, struct damon_task *t)
+/* Split every region in the given task into 'nr_subs' regions */
+static void damon_split_regions_of(struct damon_ctx *ctx,
+ struct damon_task *t, int nr_subs)
{
struct damon_region *r, *next;
- unsigned long sz_orig_region, sz_left_region;
+ unsigned long sz_region, sz_sub = 0;
+ int i;
damon_for_each_region_safe(r, next, t) {
- sz_orig_region = r->vm_end - r->vm_start;
-
- /*
- * Randomly select size of left sub-region to be at least
- * 10 percent and at most 90% of original region
- */
- sz_left_region = ALIGN_DOWN(damon_rand(1, 10) * sz_orig_region
- / 10, MIN_REGION);
- /* Do not allow blank region */
- if (sz_left_region == 0 || sz_left_region >= sz_orig_region)
- continue;
-
- damon_split_region_at(ctx, r, sz_left_region);
+ sz_region = r->vm_end - r->vm_start;
+
+ for (i = 0; i < nr_subs - 1 &&
+ sz_region > 2 * MIN_REGION; i++) {
+ /*
+ * Randomly select size of left sub-region to be at
+ * least 10 percent and at most 90% of original region
+ */
+ sz_sub = ALIGN_DOWN(damon_rand(1, 10) *
+ sz_region / 10, MIN_REGION);
+ /* Do not allow blank region */
+ if (sz_sub == 0 || sz_sub >= sz_region)
+ continue;
+
+ damon_split_region_at(ctx, r, sz_sub);
+ sz_region = sz_sub;
+ }
}
}
@@ -687,14 +693,18 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
{
struct damon_task *t;
unsigned int nr_regions = 0;
+ int nr_subregions = 2;
damon_for_each_task(ctx, t)
nr_regions += nr_damon_regions(t);
if (nr_regions > ctx->max_nr_regions / 2)
return;
+ if (nr_regions < ctx->max_nr_regions / 4)
+ nr_subregions = 4;
+
damon_for_each_task(ctx, t)
- damon_split_regions_of(ctx, t);
+ damon_split_regions_of(ctx, t, nr_subregions);
}
/*
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [PATCH v10 06/16] mm/damon: Split regions into 4 subregions if possible
2020-05-05 11:08 ` [PATCH v10 06/16] mm/damon: Split regions into 4 subregions if possible SeongJae Park
@ 2020-05-07 8:28 ` SeongJae Park
0 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-07 8:28 UTC (permalink / raw)
To: Jonathan.Cameron, SeongJae Park
Cc: akpm, SeongJae Park, aarcange, acme, alexander.shishkin, amit,
benh, brendan.d.gregg, brendanhiggins, cai, colin.king, corbet,
dwmw, irogers, jolsa, kirill, mark.rutland, mgorman, minchan,
mingo, namhyung, peterz, rdunlap, riel, rientjes, rostedt,
sblbir, shakeelb, shuah, sj38.park, snu, vbabka, vdavydov.dev,
yang.shi, ying.huang, linux-damon, linux-mm, linux-doc,
linux-kernel
On Tue, 5 May 2020 13:08:05 +0200 SeongJae Park <sjpark@amazon.com> wrote:
> From: SeongJae Park <sjpark@amazon.de>
>
> Suppose that there are a very wide and cold region and a hot region, and
> both regions are identified by DAMON. And then, the middle small region
> inside the very wide and cold region becomes hot. DAMON will not be
> able to identify this new region because the adaptive regions adjustment
> mechanism splits each region to only two subregions.
>
> This commit modifies the logic to split each region to 4 subregions if
> possible so that such problematic region can eventually identified.
As you can check with the 'Evaluations' section in the cover letter of this
patchset, the extend of the slowdown DAMON's recording feature made to the
target workload has doulbed (0.55% with v9, 1.02% with this patchset). It's
still just a small number, but the worst case slowdown is 5.29%. It was only
1.88% before. I suspect this patch is the reason, as this is the only one
major change we made after v9.
For the reason, I would like to make this patch to split each region into 3 sub
regions instead of 4 subregions. It will reduce the overhead a little bit
while still allow the corner case regions be eventually detected. If you have
other concerns or opinions, please let me know.
Thanks,
SeongJae Park
>
> Suggested-by: James Cameron <Jonathan.Cameron@Huawei.com>
> Signed-off-by: SeongJae Park <sjpark@amazon.de>
> ---
> mm/damon.c | 44 +++++++++++++++++++++++++++-----------------
> 1 file changed, 27 insertions(+), 17 deletions(-)
>
> diff --git a/mm/damon.c b/mm/damon.c
> index cec946197e13..342f905927a0 100644
> --- a/mm/damon.c
> +++ b/mm/damon.c
> @@ -650,26 +650,32 @@ static void damon_split_region_at(struct damon_ctx *ctx,
> damon_insert_region(new, r, damon_next_region(r));
> }
>
> -/* Split every region in the given task into two randomly-sized regions */
> -static void damon_split_regions_of(struct damon_ctx *ctx, struct damon_task *t)
> +/* Split every region in the given task into 'nr_subs' regions */
> +static void damon_split_regions_of(struct damon_ctx *ctx,
> + struct damon_task *t, int nr_subs)
> {
> struct damon_region *r, *next;
> - unsigned long sz_orig_region, sz_left_region;
> + unsigned long sz_region, sz_sub = 0;
> + int i;
>
> damon_for_each_region_safe(r, next, t) {
> - sz_orig_region = r->vm_end - r->vm_start;
> -
> - /*
> - * Randomly select size of left sub-region to be at least
> - * 10 percent and at most 90% of original region
> - */
> - sz_left_region = ALIGN_DOWN(damon_rand(1, 10) * sz_orig_region
> - / 10, MIN_REGION);
> - /* Do not allow blank region */
> - if (sz_left_region == 0 || sz_left_region >= sz_orig_region)
> - continue;
> -
> - damon_split_region_at(ctx, r, sz_left_region);
> + sz_region = r->vm_end - r->vm_start;
> +
> + for (i = 0; i < nr_subs - 1 &&
> + sz_region > 2 * MIN_REGION; i++) {
> + /*
> + * Randomly select size of left sub-region to be at
> + * least 10 percent and at most 90% of original region
> + */
> + sz_sub = ALIGN_DOWN(damon_rand(1, 10) *
> + sz_region / 10, MIN_REGION);
> + /* Do not allow blank region */
> + if (sz_sub == 0 || sz_sub >= sz_region)
> + continue;
> +
> + damon_split_region_at(ctx, r, sz_sub);
> + sz_region = sz_sub;
> + }
> }
> }
>
> @@ -687,14 +693,18 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
> {
> struct damon_task *t;
> unsigned int nr_regions = 0;
> + int nr_subregions = 2;
>
> damon_for_each_task(ctx, t)
> nr_regions += nr_damon_regions(t);
> if (nr_regions > ctx->max_nr_regions / 2)
> return;
>
> + if (nr_regions < ctx->max_nr_regions / 4)
> + nr_subregions = 4;
> +
> damon_for_each_task(ctx, t)
> - damon_split_regions_of(ctx, t);
> + damon_split_regions_of(ctx, t, nr_subregions);
> }
>
> /*
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v10 07/16] mm/damon: Apply dynamic memory mapping changes
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (5 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 06/16] mm/damon: Split regions into 4 subregions if possible SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 08/16] mm/damon: Implement callbacks SeongJae Park
` (8 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
Only a number of parts in the virtual address space of the processes is
mapped to physical memory and accessed. Thus, tracking the unmapped
address regions is just wasteful. However, tracking every memory
mapping change might incur an overhead. For the reason, DAMON applies
the dynamic memory mapping changes to the tracking regions only for each
of a user-specified time interval (``regions update interval``).
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 10 +++--
mm/damon.c | 101 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 106 insertions(+), 5 deletions(-)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index f1c3f491fc50..62b9f90ed87b 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -34,17 +34,21 @@ struct damon_task {
/*
* For each 'sample_interval', DAMON checks whether each region is accessed or
* not. It aggregates and keeps the access information (number of accesses to
- * each region) for each 'aggr_interval' time.
+ * each region) for 'aggr_interval' time. DAMON also checks whether the memory
+ * mapping of the target tasks has changed (e.g., by mmap() calls from the
+ * application) and applies the changes for each 'regions_update_interval'.
*
* All time intervals are in micro-seconds.
*/
struct damon_ctx {
unsigned long sample_interval;
unsigned long aggr_interval;
+ unsigned long regions_update_interval;
unsigned long min_nr_regions;
unsigned long max_nr_regions;
struct timespec64 last_aggregation;
+ struct timespec64 last_regions_update;
struct task_struct *kdamond;
bool kdamond_stop;
@@ -54,8 +58,8 @@ struct damon_ctx {
};
int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids);
-int damon_set_attrs(struct damon_ctx *ctx,
- unsigned long sample_int, unsigned long aggr_int,
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+ unsigned long aggr_int, unsigned long regions_update_int,
unsigned long min_nr_reg, unsigned long max_nr_reg);
int damon_start(struct damon_ctx *ctx);
int damon_stop(struct damon_ctx *ctx);
diff --git a/mm/damon.c b/mm/damon.c
index 342f905927a0..122a649c1321 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -707,6 +707,98 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
damon_split_regions_of(ctx, t, nr_subregions);
}
+/*
+ * Check whether it is time to check and apply the dynamic mmap changes
+ *
+ * Returns true if it is.
+ */
+static bool kdamond_need_update_regions(struct damon_ctx *ctx)
+{
+ return damon_check_reset_time_interval(&ctx->last_regions_update,
+ ctx->regions_update_interval);
+}
+
+/*
+ * Check whether regions are intersecting
+ *
+ * Note that this function checks 'struct damon_region' and 'struct region'.
+ *
+ * Returns true if it is.
+ */
+static bool damon_intersect(struct damon_region *r, struct region *re)
+{
+ return !(r->vm_end <= re->start || re->end <= r->vm_start);
+}
+
+/*
+ * Update damon regions for the three big regions of the given task
+ *
+ * t the given task
+ * bregions the three big regions of the task
+ */
+static void damon_apply_three_regions(struct damon_ctx *ctx,
+ struct damon_task *t, struct region bregions[3])
+{
+ struct damon_region *r, *next;
+ unsigned int i = 0;
+
+ /* Remove regions which are not in the three big regions now */
+ damon_for_each_region_safe(r, next, t) {
+ for (i = 0; i < 3; i++) {
+ if (damon_intersect(r, &bregions[i]))
+ break;
+ }
+ if (i == 3)
+ damon_destroy_region(r);
+ }
+
+ /* Adjust intersecting regions to fit with the three big regions */
+ for (i = 0; i < 3; i++) {
+ struct damon_region *first = NULL, *last;
+ struct damon_region *newr;
+ struct region *br;
+
+ br = &bregions[i];
+ /* Get the first and last regions which intersects with br */
+ damon_for_each_region(r, t) {
+ if (damon_intersect(r, br)) {
+ if (!first)
+ first = r;
+ last = r;
+ }
+ if (r->vm_start >= br->end)
+ break;
+ }
+ if (!first) {
+ /* no damon_region intersects with this big region */
+ newr = damon_new_region(ctx,
+ ALIGN_DOWN(br->start, MIN_REGION),
+ ALIGN(br->end, MIN_REGION));
+ if (!newr)
+ continue;
+ damon_insert_region(newr, damon_prev_region(r), r);
+ } else {
+ first->vm_start = ALIGN_DOWN(br->start, MIN_REGION);
+ last->vm_end = ALIGN(br->end, MIN_REGION);
+ }
+ }
+}
+
+/*
+ * Update regions for current memory mappings
+ */
+static void kdamond_update_regions(struct damon_ctx *ctx)
+{
+ struct region three_regions[3];
+ struct damon_task *t;
+
+ damon_for_each_task(ctx, t) {
+ if (damon_three_regions_of(t, three_regions))
+ continue;
+ damon_apply_three_regions(ctx, t, three_regions);
+ }
+}
+
/*
* Check whether current monitoring should be stopped
*
@@ -762,6 +854,9 @@ static int kdamond_fn(void *data)
kdamond_reset_aggregated(ctx);
kdamond_split_regions(ctx);
}
+
+ if (kdamond_need_update_regions(ctx))
+ kdamond_update_regions(ctx);
}
damon_for_each_task(ctx, t) {
damon_for_each_region_safe(r, next, t)
@@ -869,6 +964,7 @@ int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids)
* damon_set_attrs() - Set attributes for the monitoring.
* @ctx: monitoring context
* @sample_int: time interval between samplings
+ * @regions_update_int: time interval between vma update checks
* @aggr_int: time interval between aggregations
* @min_nr_reg: minimal number of regions
* @max_nr_reg: maximum number of regions
@@ -878,8 +974,8 @@ int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids)
*
* Return: 0 on success, negative error code otherwise.
*/
-int damon_set_attrs(struct damon_ctx *ctx,
- unsigned long sample_int, unsigned long aggr_int,
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+ unsigned long aggr_int, unsigned long regions_update_int,
unsigned long min_nr_reg, unsigned long max_nr_reg)
{
if (min_nr_reg < 3) {
@@ -895,6 +991,7 @@ int damon_set_attrs(struct damon_ctx *ctx,
ctx->sample_interval = sample_int;
ctx->aggr_interval = aggr_int;
+ ctx->regions_update_interval = regions_update_int;
ctx->min_nr_regions = min_nr_reg;
ctx->max_nr_regions = max_nr_reg;
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 08/16] mm/damon: Implement callbacks
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (6 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 07/16] mm/damon: Apply dynamic memory mapping changes SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 09/16] mm/damon: Implement access pattern recording SeongJae Park
` (7 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit implements callbacks for DAMON. Using this, DAMON users can
install their callbacks for each step of the access monitoring so that
they can do something interesting with the monitored access patterns
online. For example, callbacks can report the monitored patterns to
users or do some access pattern based memory management such as
proactive reclamations or access pattern based THP promotions/demotions
decision makings.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 4 ++++
mm/damon.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 62b9f90ed87b..264569b21502 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -55,6 +55,10 @@ struct damon_ctx {
struct mutex kdamond_lock;
struct list_head tasks_list; /* 'damon_task' objects */
+
+ /* callbacks */
+ void (*sample_cb)(struct damon_ctx *context);
+ void (*aggregate_cb)(struct damon_ctx *context);
};
int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids);
diff --git a/mm/damon.c b/mm/damon.c
index 122a649c1321..89ac5b245945 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -844,6 +844,8 @@ static int kdamond_fn(void *data)
kdamond_init_regions(ctx);
while (!kdamond_need_stop(ctx)) {
kdamond_prepare_access_checks(ctx);
+ if (ctx->sample_cb)
+ ctx->sample_cb(ctx);
usleep_range(ctx->sample_interval, ctx->sample_interval + 1);
@@ -851,6 +853,8 @@ static int kdamond_fn(void *data)
if (kdamond_aggregate_interval_passed(ctx)) {
kdamond_merge_regions(ctx, max_nr_accesses / 10);
+ if (ctx->aggregate_cb)
+ ctx->aggregate_cb(ctx);
kdamond_reset_aggregated(ctx);
kdamond_split_regions(ctx);
}
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 09/16] mm/damon: Implement access pattern recording
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (7 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 08/16] mm/damon: Implement callbacks SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 10/16] mm/damon: Add debugfs interface SeongJae Park
` (6 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit implements the recording feature of DAMON. If this feature
is enabled, DAMON writes the monitored access patterns in its binary
format into a file which specified by the user. This is already able to
be implemented by each user using the callbacks. However, as the
recording is expected to be used widely, this commit implements the
feature in the DAMON, for more convenience and efficiency.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/linux/damon.h | 7 +++
mm/damon.c | 131 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 135 insertions(+), 3 deletions(-)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 264569b21502..bc46ea00e9a1 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -50,6 +50,11 @@ struct damon_ctx {
struct timespec64 last_aggregation;
struct timespec64 last_regions_update;
+ unsigned char *rbuf;
+ unsigned int rbuf_len;
+ unsigned int rbuf_offset;
+ char *rfile_path;
+
struct task_struct *kdamond;
bool kdamond_stop;
struct mutex kdamond_lock;
@@ -65,6 +70,8 @@ int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids);
int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
unsigned long aggr_int, unsigned long regions_update_int,
unsigned long min_nr_reg, unsigned long max_nr_reg);
+int damon_set_recording(struct damon_ctx *ctx,
+ unsigned int rbuf_len, char *rfile_path);
int damon_start(struct damon_ctx *ctx);
int damon_stop(struct damon_ctx *ctx);
diff --git a/mm/damon.c b/mm/damon.c
index 89ac5b245945..dd1c5719859e 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -44,6 +44,9 @@
#define damon_for_each_task_safe(ctx, t, next) \
list_for_each_entry_safe(t, next, &(ctx)->tasks_list, list)
+#define MAX_RECORD_BUFFER_LEN (4 * 1024 * 1024)
+#define MAX_RFILE_PATH_LEN 256
+
/* Get a random number in [l, r) */
#define damon_rand(l, r) (l + prandom_u32() % (r - l))
@@ -565,16 +568,80 @@ static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx)
}
/*
- * Reset the aggregated monitoring results
+ * Flush the content in the result buffer to the result file
+ */
+static void damon_flush_rbuffer(struct damon_ctx *ctx)
+{
+ ssize_t sz;
+ loff_t pos = 0;
+ struct file *rfile;
+
+ rfile = filp_open(ctx->rfile_path, O_CREAT | O_RDWR | O_APPEND, 0644);
+ if (IS_ERR(rfile)) {
+ pr_err("Cannot open the result file %s\n",
+ ctx->rfile_path);
+ return;
+ }
+
+ while (ctx->rbuf_offset) {
+ sz = kernel_write(rfile, ctx->rbuf, ctx->rbuf_offset, &pos);
+ if (sz < 0)
+ break;
+ ctx->rbuf_offset -= sz;
+ }
+ filp_close(rfile, NULL);
+}
+
+/*
+ * Write a data into the result buffer
+ */
+static void damon_write_rbuf(struct damon_ctx *ctx, void *data, ssize_t size)
+{
+ if (!ctx->rbuf_len || !ctx->rbuf)
+ return;
+ if (ctx->rbuf_offset + size > ctx->rbuf_len)
+ damon_flush_rbuffer(ctx);
+
+ memcpy(&ctx->rbuf[ctx->rbuf_offset], data, size);
+ ctx->rbuf_offset += size;
+}
+
+/*
+ * Flush the aggregated monitoring results to the result buffer
+ *
+ * Stores current tracking results to the result buffer and reset 'nr_accesses'
+ * of each region. The format for the result buffer is as below:
+ *
+ * <time> <number of tasks> <array of task infos>
+ *
+ * task info: <pid> <number of regions> <array of region infos>
+ * region info: <start address> <end address> <nr_accesses>
*/
static void kdamond_reset_aggregated(struct damon_ctx *c)
{
struct damon_task *t;
- struct damon_region *r;
+ struct timespec64 now;
+ unsigned int nr;
+
+ ktime_get_coarse_ts64(&now);
+
+ damon_write_rbuf(c, &now, sizeof(struct timespec64));
+ nr = nr_damon_tasks(c);
+ damon_write_rbuf(c, &nr, sizeof(nr));
damon_for_each_task(c, t) {
- damon_for_each_region(r, t)
+ struct damon_region *r;
+
+ damon_write_rbuf(c, &t->pid, sizeof(t->pid));
+ nr = nr_damon_regions(t);
+ damon_write_rbuf(c, &nr, sizeof(nr));
+ damon_for_each_region(r, t) {
+ damon_write_rbuf(c, &r->vm_start, sizeof(r->vm_start));
+ damon_write_rbuf(c, &r->vm_end, sizeof(r->vm_end));
+ damon_write_rbuf(c, &r->nr_accesses,
+ sizeof(r->nr_accesses));
r->nr_accesses = 0;
+ }
}
}
@@ -830,6 +897,14 @@ static bool kdamond_need_stop(struct damon_ctx *ctx)
return true;
}
+static void kdamond_write_record_header(struct damon_ctx *ctx)
+{
+ int recfmt_ver = 1;
+
+ damon_write_rbuf(ctx, "damon_recfmt_ver", 16);
+ damon_write_rbuf(ctx, &recfmt_ver, sizeof(recfmt_ver));
+}
+
/*
* The monitoring daemon that runs as a kernel thread
*/
@@ -842,6 +917,9 @@ static int kdamond_fn(void *data)
pr_info("kdamond (%d) starts\n", ctx->kdamond->pid);
kdamond_init_regions(ctx);
+
+ kdamond_write_record_header(ctx);
+
while (!kdamond_need_stop(ctx)) {
kdamond_prepare_access_checks(ctx);
if (ctx->sample_cb)
@@ -862,6 +940,7 @@ static int kdamond_fn(void *data)
if (kdamond_need_update_regions(ctx))
kdamond_update_regions(ctx);
}
+ damon_flush_rbuffer(ctx);
damon_for_each_task(ctx, t) {
damon_for_each_region_safe(r, next, t)
damon_destroy_region(r);
@@ -964,6 +1043,52 @@ int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids)
return 0;
}
+/**
+ * damon_set_recording() - Set attributes for the recording.
+ * @ctx: target kdamond context
+ * @rbuf_len: length of the result buffer
+ * @rfile_path: path to the monitor result files
+ *
+ * Setting 'rbuf_len' 0 disables recording.
+ *
+ * This function should not be called while the kdamond is running.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_set_recording(struct damon_ctx *ctx,
+ unsigned int rbuf_len, char *rfile_path)
+{
+ size_t rfile_path_len;
+
+ if (rbuf_len > MAX_RECORD_BUFFER_LEN) {
+ pr_err("too long (>%d) result buffer length\n",
+ MAX_RECORD_BUFFER_LEN);
+ return -EINVAL;
+ }
+ rfile_path_len = strnlen(rfile_path, MAX_RFILE_PATH_LEN);
+ if (rfile_path_len >= MAX_RFILE_PATH_LEN) {
+ pr_err("too long (>%d) result file path %s\n",
+ MAX_RFILE_PATH_LEN, rfile_path);
+ return -EINVAL;
+ }
+ ctx->rbuf_len = rbuf_len;
+ kfree(ctx->rbuf);
+ kfree(ctx->rfile_path);
+ ctx->rfile_path = NULL;
+ if (!rbuf_len) {
+ ctx->rbuf = NULL;
+ } else {
+ ctx->rbuf = kvmalloc(rbuf_len, GFP_KERNEL);
+ if (!ctx->rbuf)
+ return -ENOMEM;
+ }
+ ctx->rfile_path = kmalloc(rfile_path_len + 1, GFP_KERNEL);
+ if (!ctx->rfile_path)
+ return -ENOMEM;
+ strncpy(ctx->rfile_path, rfile_path, rfile_path_len + 1);
+ return 0;
+}
+
/**
* damon_set_attrs() - Set attributes for the monitoring.
* @ctx: monitoring context
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 10/16] mm/damon: Add debugfs interface
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (8 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 09/16] mm/damon: Implement access pattern recording SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 11/16] mm/damon: Add tracepoints SeongJae Park
` (5 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds a debugfs interface for DAMON.
DAMON exports four files, ``attrs``, ``pids``, ``record``, and
``monitor_on`` under its debugfs directory, ``<debugfs>/damon/``.
Attributes
----------
Users can read and write the ``sampling interval``, ``aggregation
interval``, ``regions update interval``, and min/max number of
monitoring target regions by reading from and writing to the ``attrs``
file. For example, below commands set those values to 5 ms, 100 ms,
1,000 ms, 10, 1000 and check it again::
# cd <debugfs>/damon
# echo 5000 100000 1000000 10 1000 > attrs
# cat attrs
5000 100000 1000000 10 1000
Target PIDs
-----------
Users can read and write the pids of current monitoring target processes
by reading from and writing to the ``pids`` file. For example, below
commands set processes having pids 42 and 4242 as the processes to be
monitored and check it again::
# cd <debugfs>/damon
# echo 42 4242 > pids
# cat pids
42 4242
Note that setting the pids doesn't start the monitoring.
Record
------
DAMON supports direct monitoring result record feature. The recorded
results are first written to a buffer and flushed to a file in batch.
Users can set the size of the buffer and the path to the result file by
reading from and writing to the ``record`` file. For example, below
commands set the buffer to be 4 KiB and the result to be saved in
'/damon.data'.
# cd <debugfs>/damon
# echo 4096 /damon.data > pids
# cat record
4096 /damon.data
Turning On/Off
--------------
You can check current status, start and stop the monitoring by reading
from and writing to the ``monitor_on`` file. Writing ``on`` to the file
starts DAMON to monitor the target processes with the attributes.
Writing ``off`` to the file stops DAMON. DAMON also stops if every
target processes is terminated. Below example commands turn on, off,
and check status of DAMON::
# cd <debugfs>/damon
# echo on > monitor_on
# echo off > monitor_on
# cat monitor_on
off
Please note that you cannot write to the ``attrs`` and ``pids`` files
while the monitoring is turned on. If you write to the files while
DAMON is running, ``-EINVAL`` will be returned.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
mm/damon.c | 351 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 350 insertions(+), 1 deletion(-)
diff --git a/mm/damon.c b/mm/damon.c
index dd1c5719859e..fac56448847f 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -10,6 +10,7 @@
#define pr_fmt(fmt) "damon: " fmt
#include <linux/damon.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/mm.h>
@@ -50,6 +51,15 @@
/* Get a random number in [l, r) */
#define damon_rand(l, r) (l + prandom_u32() % (r - l))
+/* A monitoring context for debugfs interface users. */
+static struct damon_ctx damon_user_ctx = {
+ .sample_interval = 5 * 1000,
+ .aggr_interval = 100 * 1000,
+ .regions_update_interval = 1000 * 1000,
+ .min_nr_regions = 10,
+ .max_nr_regions = 1000,
+};
+
/*
* Construct a damon_region struct
*
@@ -1127,13 +1137,352 @@ int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
return 0;
}
-static int __init damon_init(void)
+static ssize_t debugfs_monitor_on_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char monitor_on_buf[5];
+ bool monitor_on;
+ int len;
+
+ monitor_on = damon_kdamond_running(ctx);
+ len = snprintf(monitor_on_buf, 5, monitor_on ? "on\n" : "off\n");
+
+ return simple_read_from_buffer(buf, count, ppos, monitor_on_buf, len);
+}
+
+static ssize_t debugfs_monitor_on_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ ssize_t ret;
+ char cmdbuf[5];
+ int err;
+
+ ret = simple_write_to_buffer(cmdbuf, 5, ppos, buf, count);
+ if (ret < 0)
+ return ret;
+
+ if (sscanf(cmdbuf, "%s", cmdbuf) != 1)
+ return -EINVAL;
+ if (!strncmp(cmdbuf, "on", 5))
+ err = damon_start(ctx);
+ else if (!strncmp(cmdbuf, "off", 5))
+ err = damon_stop(ctx);
+ else
+ return -EINVAL;
+
+ if (err)
+ ret = err;
+ return ret;
+}
+
+static ssize_t damon_sprint_pids(struct damon_ctx *ctx, char *buf, ssize_t len)
+{
+ struct damon_task *t;
+ int written = 0;
+ int rc;
+
+ damon_for_each_task(ctx, t) {
+ rc = snprintf(&buf[written], len - written, "%d ", t->pid);
+ if (!rc)
+ return -ENOMEM;
+ written += rc;
+ }
+ if (written)
+ written -= 1;
+ written += snprintf(&buf[written], len - written, "\n");
+ return written;
+}
+
+static ssize_t debugfs_pids_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ ssize_t len;
+ char pids_buf[320];
+
+ len = damon_sprint_pids(ctx, pids_buf, 320);
+ if (len < 0)
+ return len;
+
+ return simple_read_from_buffer(buf, count, ppos, pids_buf, len);
+}
+
+/*
+ * Converts a string into an array of unsigned long integers
+ *
+ * Returns an array of unsigned long integers if the conversion success, or
+ * NULL otherwise.
+ */
+static int *str_to_pids(const char *str, ssize_t len, ssize_t *nr_pids)
+{
+ int *pids;
+ const int max_nr_pids = 32;
+ int pid;
+ int pos = 0, parsed, ret;
+
+ *nr_pids = 0;
+ pids = kmalloc_array(max_nr_pids, sizeof(pid), GFP_KERNEL);
+ if (!pids)
+ return NULL;
+ while (*nr_pids < max_nr_pids && pos < len) {
+ ret = sscanf(&str[pos], "%d%n", &pid, &parsed);
+ pos += parsed;
+ if (ret != 1)
+ break;
+ pids[*nr_pids] = pid;
+ *nr_pids += 1;
+ }
+ if (*nr_pids == 0) {
+ kfree(pids);
+ pids = NULL;
+ }
+
+ return pids;
+}
+
+static ssize_t debugfs_pids_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char *kbuf;
+ int *targets;
+ ssize_t nr_targets;
+ ssize_t ret;
+ int err;
+
+ kbuf = kmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ ret = simple_write_to_buffer(kbuf, count, ppos, buf, count);
+ if (ret < 0)
+ goto out;
+
+ targets = str_to_pids(kbuf, ret, &nr_targets);
+ if (!targets) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond) {
+ ret = -EINVAL;
+ goto unlock_out;
+ }
+
+ err = damon_set_pids(ctx, targets, nr_targets);
+ if (err)
+ ret = err;
+unlock_out:
+ mutex_unlock(&ctx->kdamond_lock);
+ kfree(targets);
+out:
+ kfree(kbuf);
+ return ret;
+}
+
+static ssize_t debugfs_record_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char record_buf[20 + MAX_RFILE_PATH_LEN];
+ int ret;
+
+ ret = snprintf(record_buf, ARRAY_SIZE(record_buf), "%u %s\n",
+ ctx->rbuf_len, ctx->rfile_path);
+ return simple_read_from_buffer(buf, count, ppos, record_buf, ret);
+}
+
+static ssize_t debugfs_record_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char *kbuf;
+ unsigned int rbuf_len;
+ char rfile_path[MAX_RFILE_PATH_LEN];
+ ssize_t ret;
+ int err;
+
+ kbuf = kmalloc(count + 1, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+ kbuf[count] = '\0';
+
+ ret = simple_write_to_buffer(kbuf, count, ppos, buf, count);
+ if (ret < 0)
+ goto out;
+ if (sscanf(kbuf, "%u %s",
+ &rbuf_len, rfile_path) != 2) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond) {
+ ret = -EBUSY;
+ goto unlock_out;
+ }
+
+ err = damon_set_recording(ctx, rbuf_len, rfile_path);
+ if (err)
+ ret = err;
+unlock_out:
+ mutex_unlock(&ctx->kdamond_lock);
+out:
+ kfree(kbuf);
+ return ret;
+}
+
+
+static ssize_t debugfs_attrs_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char kbuf[128];
+ int ret;
+
+ ret = snprintf(kbuf, ARRAY_SIZE(kbuf), "%lu %lu %lu %lu %lu\n",
+ ctx->sample_interval, ctx->aggr_interval,
+ ctx->regions_update_interval, ctx->min_nr_regions,
+ ctx->max_nr_regions);
+
+ return simple_read_from_buffer(buf, count, ppos, kbuf, ret);
+}
+
+static ssize_t debugfs_attrs_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ unsigned long s, a, r, minr, maxr;
+ char *kbuf;
+ ssize_t ret;
+ int err;
+
+ kbuf = kmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ ret = simple_write_to_buffer(kbuf, count, ppos, buf, count);
+ if (ret < 0)
+ goto out;
+
+ if (sscanf(kbuf, "%lu %lu %lu %lu %lu",
+ &s, &a, &r, &minr, &maxr) != 5) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond) {
+ ret = -EBUSY;
+ goto unlock_out;
+ }
+
+ err = damon_set_attrs(ctx, s, a, r, minr, maxr);
+ if (err)
+ ret = err;
+unlock_out:
+ mutex_unlock(&ctx->kdamond_lock);
+out:
+ kfree(kbuf);
+ return ret;
+}
+
+static const struct file_operations monitor_on_fops = {
+ .owner = THIS_MODULE,
+ .read = debugfs_monitor_on_read,
+ .write = debugfs_monitor_on_write,
+};
+
+static const struct file_operations pids_fops = {
+ .owner = THIS_MODULE,
+ .read = debugfs_pids_read,
+ .write = debugfs_pids_write,
+};
+
+static const struct file_operations record_fops = {
+ .owner = THIS_MODULE,
+ .read = debugfs_record_read,
+ .write = debugfs_record_write,
+};
+
+static const struct file_operations attrs_fops = {
+ .owner = THIS_MODULE,
+ .read = debugfs_attrs_read,
+ .write = debugfs_attrs_write,
+};
+
+static struct dentry *debugfs_root;
+
+static int __init damon_debugfs_init(void)
+{
+ const char * const file_names[] = {"attrs", "record",
+ "pids", "monitor_on"};
+ const struct file_operations *fops[] = {&attrs_fops, &record_fops,
+ &pids_fops, &monitor_on_fops};
+ int i;
+
+ debugfs_root = debugfs_create_dir("damon", NULL);
+ if (!debugfs_root) {
+ pr_err("failed to create the debugfs dir\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(file_names); i++) {
+ if (!debugfs_create_file(file_names[i], 0600, debugfs_root,
+ NULL, fops[i])) {
+ pr_err("failed to create %s file\n", file_names[i]);
+ return -ENOMEM;
+ }
+ }
+
return 0;
}
+static int __init damon_init_user_ctx(void)
+{
+ int rc;
+
+ struct damon_ctx *ctx = &damon_user_ctx;
+
+ ktime_get_coarse_ts64(&ctx->last_aggregation);
+ ctx->last_regions_update = ctx->last_aggregation;
+
+ rc = damon_set_recording(ctx, 1024 * 1024, "/damon.data");
+ if (rc)
+ return rc;
+
+ mutex_init(&ctx->kdamond_lock);
+
+ INIT_LIST_HEAD(&ctx->tasks_list);
+
+ return 0;
+}
+
+static int __init damon_init(void)
+{
+ int rc;
+
+ rc = damon_init_user_ctx();
+ if (rc)
+ return rc;
+
+ rc = damon_debugfs_init();
+ if (rc)
+ pr_err("%s: debugfs init failed\n", __func__);
+
+ return rc;
+}
+
static void __exit damon_exit(void)
{
+ damon_stop(&damon_user_ctx);
+ debugfs_remove_recursive(debugfs_root);
+
+ kfree(damon_user_ctx.rbuf);
+ kfree(damon_user_ctx.rfile_path);
}
module_init(damon_init);
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 11/16] mm/damon: Add tracepoints
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (9 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 10/16] mm/damon: Add debugfs interface SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 12/16] tools: Add a minimal user-space tool for DAMON SeongJae Park
` (4 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds a tracepoint for DAMON. It traces the monitoring
results of each region for each aggregation interval. Using this, DAMON
will be easily integrated with any tracepoints supporting tools such as
perf.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
include/trace/events/damon.h | 43 ++++++++++++++++++++++++++++++++++++
mm/damon.c | 5 +++++
2 files changed, 48 insertions(+)
create mode 100644 include/trace/events/damon.h
diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h
new file mode 100644
index 000000000000..22236642d366
--- /dev/null
+++ b/include/trace/events/damon.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM damon
+
+#if !defined(_TRACE_DAMON_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DAMON_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(damon_aggregated,
+
+ TP_PROTO(int pid, unsigned int nr_regions,
+ unsigned long vm_start, unsigned long vm_end,
+ unsigned int nr_accesses),
+
+ TP_ARGS(pid, nr_regions, vm_start, vm_end, nr_accesses),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ __field(unsigned int, nr_regions)
+ __field(unsigned long, vm_start)
+ __field(unsigned long, vm_end)
+ __field(unsigned int, nr_accesses)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ __entry->nr_regions = nr_regions;
+ __entry->vm_start = vm_start;
+ __entry->vm_end = vm_end;
+ __entry->nr_accesses = nr_accesses;
+ ),
+
+ TP_printk("pid=%d nr_regions=%u %lu-%lu: %u", __entry->pid,
+ __entry->nr_regions, __entry->vm_start,
+ __entry->vm_end, __entry->nr_accesses)
+);
+
+#endif /* _TRACE_DAMON_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/mm/damon.c b/mm/damon.c
index fac56448847f..9f7d173eca3b 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -9,6 +9,8 @@
#define pr_fmt(fmt) "damon: " fmt
+#define CREATE_TRACE_POINTS
+
#include <linux/damon.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
@@ -20,6 +22,7 @@
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/slab.h>
+#include <trace/events/damon.h>
/* Minimal region size. Every damon_region is aligned by this. */
#define MIN_REGION PAGE_SIZE
@@ -650,6 +653,8 @@ static void kdamond_reset_aggregated(struct damon_ctx *c)
damon_write_rbuf(c, &r->vm_end, sizeof(r->vm_end));
damon_write_rbuf(c, &r->nr_accesses,
sizeof(r->nr_accesses));
+ trace_damon_aggregated(t->pid, nr,
+ r->vm_start, r->vm_end, r->nr_accesses);
r->nr_accesses = 0;
}
}
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 12/16] tools: Add a minimal user-space tool for DAMON
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (10 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 11/16] mm/damon: Add tracepoints SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 13/16] Documentation/admin-guide/mm: Add a document " SeongJae Park
` (3 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds a shallow wrapper python script, ``/tools/damon/damo``
that provides more convenient interface. Note that it is only aimed to
be used for minimal reference of the DAMON's debugfs interfaces and for
debugging of the DAMON itself.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
tools/damon/.gitignore | 1 +
tools/damon/_dist.py | 36 ++++
tools/damon/_recfile.py | 23 +++
tools/damon/bin2txt.py | 67 +++++++
tools/damon/damo | 37 ++++
tools/damon/heats.py | 362 ++++++++++++++++++++++++++++++++++++++
tools/damon/nr_regions.py | 91 ++++++++++
tools/damon/record.py | 212 ++++++++++++++++++++++
tools/damon/report.py | 45 +++++
tools/damon/wss.py | 97 ++++++++++
10 files changed, 971 insertions(+)
create mode 100644 tools/damon/.gitignore
create mode 100644 tools/damon/_dist.py
create mode 100644 tools/damon/_recfile.py
create mode 100644 tools/damon/bin2txt.py
create mode 100755 tools/damon/damo
create mode 100644 tools/damon/heats.py
create mode 100644 tools/damon/nr_regions.py
create mode 100644 tools/damon/record.py
create mode 100644 tools/damon/report.py
create mode 100644 tools/damon/wss.py
diff --git a/tools/damon/.gitignore b/tools/damon/.gitignore
new file mode 100644
index 000000000000..96403d36ff93
--- /dev/null
+++ b/tools/damon/.gitignore
@@ -0,0 +1 @@
+__pycache__/*
diff --git a/tools/damon/_dist.py b/tools/damon/_dist.py
new file mode 100644
index 000000000000..9851ec964e5c
--- /dev/null
+++ b/tools/damon/_dist.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import os
+import struct
+import subprocess
+
+def access_patterns(f):
+ nr_regions = struct.unpack('I', f.read(4))[0]
+
+ patterns = []
+ for r in range(nr_regions):
+ saddr = struct.unpack('L', f.read(8))[0]
+ eaddr = struct.unpack('L', f.read(8))[0]
+ nr_accesses = struct.unpack('I', f.read(4))[0]
+ patterns.append([eaddr - saddr, nr_accesses])
+ return patterns
+
+def plot_dist(data_file, output_file, xlabel, ylabel):
+ terminal = output_file.split('.')[-1]
+ if not terminal in ['pdf', 'jpeg', 'png', 'svg']:
+ os.remove(data_file)
+ print("Unsupported plot output type.")
+ exit(-1)
+
+ gnuplot_cmd = """
+ set term %s;
+ set output '%s';
+ set key off;
+ set xlabel '%s';
+ set ylabel '%s';
+ plot '%s' with linespoints;""" % (terminal, output_file, xlabel, ylabel,
+ data_file)
+ subprocess.call(['gnuplot', '-e', gnuplot_cmd])
+ os.remove(data_file)
+
diff --git a/tools/damon/_recfile.py b/tools/damon/_recfile.py
new file mode 100644
index 000000000000..331b4d8165d8
--- /dev/null
+++ b/tools/damon/_recfile.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import struct
+
+fmt_version = 0
+
+def set_fmt_version(f):
+ global fmt_version
+
+ mark = f.read(16)
+ if mark == b'damon_recfmt_ver':
+ fmt_version = struct.unpack('i', f.read(4))[0]
+ else:
+ fmt_version = 0
+ f.seek(0)
+ return fmt_version
+
+def pid(f):
+ if fmt_version == 0:
+ return struct.unpack('L', f.read(8))[0]
+ else:
+ return struct.unpack('i', f.read(4))[0]
diff --git a/tools/damon/bin2txt.py b/tools/damon/bin2txt.py
new file mode 100644
index 000000000000..8b9b57a0d727
--- /dev/null
+++ b/tools/damon/bin2txt.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import argparse
+import os
+import struct
+import sys
+
+import _recfile
+
+def parse_time(bindat):
+ "bindat should be 16 bytes"
+ sec = struct.unpack('l', bindat[0:8])[0]
+ nsec = struct.unpack('l', bindat[8:16])[0]
+ return sec * 1000000000 + nsec;
+
+def pr_region(f):
+ saddr = struct.unpack('L', f.read(8))[0]
+ eaddr = struct.unpack('L', f.read(8))[0]
+ nr_accesses = struct.unpack('I', f.read(4))[0]
+ print("%012x-%012x(%10d):\t%d" %
+ (saddr, eaddr, eaddr - saddr, nr_accesses))
+
+def pr_task_info(f):
+ pid = _recfile.pid(f)
+ print("pid: ", pid)
+ nr_regions = struct.unpack('I', f.read(4))[0]
+ print("nr_regions: ", nr_regions)
+ for r in range(nr_regions):
+ pr_region(f)
+
+def set_argparser(parser):
+ parser.add_argument('--input', '-i', type=str, metavar='<file>',
+ default='damon.data', help='input file name')
+
+def main(args=None):
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ file_path = args.input
+
+ if not os.path.isfile(file_path):
+ print('input file (%s) is not exist' % file_path)
+ exit(1)
+
+ with open(file_path, 'rb') as f:
+ _recfile.set_fmt_version(f)
+ start_time = None
+ while True:
+ timebin = f.read(16)
+ if len(timebin) != 16:
+ break
+ time = parse_time(timebin)
+ if not start_time:
+ start_time = time
+ print("start_time: ", start_time)
+ print("rel time: %16d" % (time - start_time))
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ print("nr_tasks: ", nr_tasks)
+ for t in range(nr_tasks):
+ pr_task_info(f)
+ print("")
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/damon/damo b/tools/damon/damo
new file mode 100755
index 000000000000..58e1099ae5fc
--- /dev/null
+++ b/tools/damon/damo
@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import argparse
+
+import record
+import report
+
+class SubCmdHelpFormatter(argparse.RawDescriptionHelpFormatter):
+ def _format_action(self, action):
+ parts = super(argparse.RawDescriptionHelpFormatter,
+ self)._format_action(action)
+ # skip sub parsers help
+ if action.nargs == argparse.PARSER:
+ parts = '\n'.join(parts.split('\n')[1:])
+ return parts
+
+parser = argparse.ArgumentParser(formatter_class=SubCmdHelpFormatter)
+
+subparser = parser.add_subparsers(title='command', dest='command',
+ metavar='<command>')
+subparser.required = True
+
+parser_record = subparser.add_parser('record',
+ help='record data accesses of the given target processes')
+record.set_argparser(parser_record)
+
+parser_report = subparser.add_parser('report',
+ help='report the recorded data accesses in the specified form')
+report.set_argparser(parser_report)
+
+args = parser.parse_args()
+
+if args.command == 'record':
+ record.main(args)
+elif args.command == 'report':
+ report.main(args)
diff --git a/tools/damon/heats.py b/tools/damon/heats.py
new file mode 100644
index 000000000000..99837083874e
--- /dev/null
+++ b/tools/damon/heats.py
@@ -0,0 +1,362 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Transform binary trace data into human readable text that can be used for
+heatmap drawing, or directly plot the data in a heatmap format.
+
+Format of the text is:
+
+ <time> <space> <heat>
+ ...
+
+"""
+
+import argparse
+import os
+import struct
+import subprocess
+import sys
+import tempfile
+
+import _recfile
+
+class HeatSample:
+ space_idx = None
+ sz_time_space = None
+ heat = None
+
+ def __init__(self, space_idx, sz_time_space, heat):
+ if sz_time_space < 0:
+ raise RuntimeError()
+ self.space_idx = space_idx
+ self.sz_time_space = sz_time_space
+ self.heat = heat
+
+ def total_heat(self):
+ return self.heat * self.sz_time_space
+
+ def merge(self, sample):
+ "sample must have a space idx that same to self"
+ heat_sum = self.total_heat() + sample.total_heat()
+ self.heat = heat_sum / (self.sz_time_space + sample.sz_time_space)
+ self.sz_time_space += sample.sz_time_space
+
+def pr_samples(samples, time_idx, time_unit, region_unit):
+ display_time = time_idx * time_unit
+ for idx, sample in enumerate(samples):
+ display_addr = idx * region_unit
+ if not sample:
+ print("%s\t%s\t%s" % (display_time, display_addr, 0.0))
+ continue
+ print("%s\t%s\t%s" % (display_time, display_addr, sample.total_heat() /
+ time_unit / region_unit))
+
+def to_idx(value, min_, unit):
+ return (value - min_) // unit
+
+def read_task_heats(f, pid, aunit, amin, amax):
+ pid_ = _recfile.pid(f)
+ nr_regions = struct.unpack('I', f.read(4))[0]
+ if pid_ != pid:
+ f.read(20 * nr_regions)
+ return None
+ samples = []
+ for i in range(nr_regions):
+ saddr = struct.unpack('L', f.read(8))[0]
+ eaddr = struct.unpack('L', f.read(8))[0]
+ eaddr = min(eaddr, amax - 1)
+ heat = struct.unpack('I', f.read(4))[0]
+
+ if eaddr <= amin:
+ continue
+ if saddr >= amax:
+ continue
+ saddr = max(amin, saddr)
+ eaddr = min(amax, eaddr)
+
+ sidx = to_idx(saddr, amin, aunit)
+ eidx = to_idx(eaddr - 1, amin, aunit)
+ for idx in range(sidx, eidx + 1):
+ sa = max(amin + idx * aunit, saddr)
+ ea = min(amin + (idx + 1) * aunit, eaddr)
+ sample = HeatSample(idx, (ea - sa), heat)
+ samples.append(sample)
+ return samples
+
+def parse_time(bindat):
+ sec = struct.unpack('l', bindat[0:8])[0]
+ nsec = struct.unpack('l', bindat[8:16])[0]
+ return sec * 1000000000 + nsec
+
+def apply_samples(target_samples, samples, start_time, end_time, aunit, amin):
+ for s in samples:
+ sample = HeatSample(s.space_idx,
+ s.sz_time_space * (end_time - start_time), s.heat)
+ idx = sample.space_idx
+ if not target_samples[idx]:
+ target_samples[idx] = sample
+ else:
+ target_samples[idx].merge(sample)
+
+def __pr_heats(f, pid, tunit, tmin, tmax, aunit, amin, amax):
+ heat_samples = [None] * ((amax - amin) // aunit)
+
+ start_time = 0
+ end_time = 0
+ last_flushed = -1
+ while True:
+ start_time = end_time
+ timebin = f.read(16)
+ if (len(timebin)) != 16:
+ break
+ end_time = parse_time(timebin)
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ samples_set = {}
+ for t in range(nr_tasks):
+ samples = read_task_heats(f, pid, aunit, amin, amax)
+ if samples:
+ samples_set[pid] = samples
+ if not pid in samples_set:
+ continue
+ if start_time >= tmax:
+ continue
+ if end_time <= tmin:
+ continue
+ start_time = max(start_time, tmin)
+ end_time = min(end_time, tmax)
+
+ sidx = to_idx(start_time, tmin, tunit)
+ eidx = to_idx(end_time - 1, tmin, tunit)
+ for idx in range(sidx, eidx + 1):
+ if idx != last_flushed:
+ pr_samples(heat_samples, idx, tunit, aunit)
+ heat_samples = [None] * ((amax - amin) // aunit)
+ last_flushed = idx
+ st = max(start_time, tmin + idx * tunit)
+ et = min(end_time, tmin + (idx + 1) * tunit)
+ apply_samples(heat_samples, samples_set[pid], st, et, aunit, amin)
+
+def pr_heats(args):
+ binfile = args.input
+ pid = args.pid
+ tres = args.tres
+ tmin = args.tmin
+ ares = args.ares
+ amin = args.amin
+
+ tunit = (args.tmax - tmin) // tres
+ aunit = (args.amax - amin) // ares
+
+ # Compensate the values so that those fit with the resolution
+ tmax = tmin + tunit * tres
+ amax = amin + aunit * ares
+
+ with open(binfile, 'rb') as f:
+ _recfile.set_fmt_version(f)
+ __pr_heats(f, pid, tunit, tmin, tmax, aunit, amin, amax)
+
+class GuideInfo:
+ pid = None
+ start_time = None
+ end_time = None
+ lowest_addr = None
+ highest_addr = None
+ gaps = None
+
+ def __init__(self, pid, start_time):
+ self.pid = pid
+ self.start_time = start_time
+ self.gaps = []
+
+ def regions(self):
+ regions = []
+ region = [self.lowest_addr]
+ for gap in self.gaps:
+ for idx, point in enumerate(gap):
+ if idx == 0:
+ region.append(point)
+ regions.append(region)
+ else:
+ region = [point]
+ region.append(self.highest_addr)
+ regions.append(region)
+ return regions
+
+ def total_space(self):
+ ret = 0
+ for r in self.regions():
+ ret += r[1] - r[0]
+ return ret
+
+ def __str__(self):
+ lines = ['pid:%d' % self.pid]
+ lines.append('time: %d-%d (%d)' % (self.start_time, self.end_time,
+ self.end_time - self.start_time))
+ for idx, region in enumerate(self.regions()):
+ lines.append('region\t%2d: %020d-%020d (%d)' %
+ (idx, region[0], region[1], region[1] - region[0]))
+ return '\n'.join(lines)
+
+def is_overlap(region1, region2):
+ if region1[1] < region2[0]:
+ return False
+ if region2[1] < region1[0]:
+ return False
+ return True
+
+def overlap_region_of(region1, region2):
+ return [max(region1[0], region2[0]), min(region1[1], region2[1])]
+
+def overlapping_regions(regions1, regions2):
+ overlap_regions = []
+ for r1 in regions1:
+ for r2 in regions2:
+ if is_overlap(r1, r2):
+ r1 = overlap_region_of(r1, r2)
+ if r1:
+ overlap_regions.append(r1)
+ return overlap_regions
+
+def get_guide_info(binfile):
+ "Read file, return the set of guide information objects of the data"
+ guides = {}
+ with open(binfile, 'rb') as f:
+ _recfile.set_fmt_version(f)
+ while True:
+ timebin = f.read(16)
+ if len(timebin) != 16:
+ break
+ monitor_time = parse_time(timebin)
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ for t in range(nr_tasks):
+ pid = _recfile.pid(f)
+ nr_regions = struct.unpack('I', f.read(4))[0]
+ if not pid in guides:
+ guides[pid] = GuideInfo(pid, monitor_time)
+ guide = guides[pid]
+ guide.end_time = monitor_time
+
+ last_addr = None
+ gaps = []
+ for r in range(nr_regions):
+ saddr = struct.unpack('L', f.read(8))[0]
+ eaddr = struct.unpack('L', f.read(8))[0]
+ f.read(4)
+
+ if not guide.lowest_addr or saddr < guide.lowest_addr:
+ guide.lowest_addr = saddr
+ if not guide.highest_addr or eaddr > guide.highest_addr:
+ guide.highest_addr = eaddr
+
+ if not last_addr:
+ last_addr = eaddr
+ continue
+ if last_addr != saddr:
+ gaps.append([last_addr, saddr])
+ last_addr = eaddr
+
+ if not guide.gaps:
+ guide.gaps = gaps
+ else:
+ guide.gaps = overlapping_regions(guide.gaps, gaps)
+ return sorted(list(guides.values()), key=lambda x: x.total_space(),
+ reverse=True)
+
+def pr_guide(binfile):
+ for guide in get_guide_info(binfile):
+ print(guide)
+
+def region_sort_key(region):
+ return region[1] - region[0]
+
+def set_missed_args(args):
+ if args.pid and args.tmin and args.tmax and args.amin and args.amax:
+ return
+ guides = get_guide_info(args.input)
+ guide = guides[0]
+ if not args.pid:
+ args.pid = guide.pid
+ for g in guides:
+ if g.pid == args.pid:
+ guide = g
+ break
+
+ if not args.tmin:
+ args.tmin = guide.start_time
+ if not args.tmax:
+ args.tmax = guide.end_time
+
+ if not args.amin or not args.amax:
+ region = sorted(guide.regions(), key=lambda x: x[1] - x[0],
+ reverse=True)[0]
+ args.amin = region[0]
+ args.amax = region[1]
+
+def plot_heatmap(data_file, output_file):
+ terminal = output_file.split('.')[-1]
+ if not terminal in ['pdf', 'jpeg', 'png', 'svg']:
+ os.remove(data_file)
+ print("Unsupported plot output type.")
+ exit(-1)
+
+ gnuplot_cmd = """
+ set term %s;
+ set output '%s';
+ set key off;
+ set xrange [0:];
+ set yrange [0:];
+ set xlabel 'Time (ns)';
+ set ylabel 'Virtual Address (bytes)';
+ plot '%s' using 1:2:3 with image;""" % (terminal, output_file, data_file)
+ subprocess.call(['gnuplot', '-e', gnuplot_cmd])
+ os.remove(data_file)
+
+def set_argparser(parser):
+ parser.add_argument('--input', '-i', type=str, metavar='<file>',
+ default='damon.data', help='input file name')
+ parser.add_argument('--pid', metavar='<pid>', type=int,
+ help='pid of target task')
+ parser.add_argument('--tres', metavar='<resolution>', type=int,
+ default=500, help='time resolution of the output')
+ parser.add_argument('--tmin', metavar='<time>', type=lambda x: int(x,0),
+ help='minimal time of the output')
+ parser.add_argument('--tmax', metavar='<time>', type=lambda x: int(x,0),
+ help='maximum time of the output')
+ parser.add_argument('--ares', metavar='<resolution>', type=int, default=500,
+ help='space address resolution of the output')
+ parser.add_argument('--amin', metavar='<address>', type=lambda x: int(x,0),
+ help='minimal space address of the output')
+ parser.add_argument('--amax', metavar='<address>', type=lambda x: int(x,0),
+ help='maximum space address of the output')
+ parser.add_argument('--guide', action='store_true',
+ help='print a guidance for the min/max/resolution settings')
+ parser.add_argument('--heatmap', metavar='<file>', type=str,
+ help='heatmap image file to create')
+
+def main(args=None):
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ if args.guide:
+ pr_guide(args.input)
+ else:
+ set_missed_args(args)
+ orig_stdout = sys.stdout
+ if args.heatmap:
+ tmp_path = tempfile.mkstemp()[1]
+ tmp_file = open(tmp_path, 'w')
+ sys.stdout = tmp_file
+
+ pr_heats(args)
+
+ if args.heatmap:
+ sys.stdout = orig_stdout
+ tmp_file.flush()
+ tmp_file.close()
+ plot_heatmap(tmp_path, args.heatmap)
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/damon/nr_regions.py b/tools/damon/nr_regions.py
new file mode 100644
index 000000000000..655ee50a7b8d
--- /dev/null
+++ b/tools/damon/nr_regions.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"Print out distribution of the number of regions in the given record"
+
+import argparse
+import struct
+import sys
+import tempfile
+
+import _dist
+import _recfile
+
+def set_argparser(parser):
+ parser.add_argument('--input', '-i', type=str, metavar='<file>',
+ default='damon.data', help='input file name')
+ parser.add_argument('--range', '-r', type=int, nargs=3,
+ metavar=('<start>', '<stop>', '<step>'),
+ help='range of percentiles to print')
+ parser.add_argument('--sortby', '-s', choices=['time', 'size'],
+ help='the metric to be used for sorting the number of regions')
+ parser.add_argument('--plot', '-p', type=str, metavar='<file>',
+ help='plot the distribution to an image file')
+
+def main(args=None):
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ percentiles = [0, 25, 50, 75, 100]
+
+ file_path = args.input
+ if args.range:
+ percentiles = range(args.range[0], args.range[1], args.range[2])
+ nr_regions_sort = True
+ if args.sortby == 'time':
+ nr_regions_sort = False
+
+ pid_pattern_map = {}
+ with open(file_path, 'rb') as f:
+ _recfile.set_fmt_version(f)
+ start_time = None
+ while True:
+ timebin = f.read(16)
+ if len(timebin) != 16:
+ break
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ for t in range(nr_tasks):
+ pid = _recfile.pid(f)
+ if not pid in pid_pattern_map:
+ pid_pattern_map[pid] = []
+ pid_pattern_map[pid].append(_dist.access_patterns(f))
+
+ orig_stdout = sys.stdout
+ if args.plot:
+ tmp_path = tempfile.mkstemp()[1]
+ tmp_file = open(tmp_path, 'w')
+ sys.stdout = tmp_file
+
+ print('# <percentile> <# regions>')
+ for pid in pid_pattern_map.keys():
+ # Skip firs 20 regions as those would not adaptively adjusted
+ snapshots = pid_pattern_map[pid][20:]
+ nr_regions_dist = []
+ for snapshot in snapshots:
+ nr_regions_dist.append(len(snapshot))
+ if nr_regions_sort:
+ nr_regions_dist.sort(reverse=False)
+
+ print('# pid\t%s' % pid)
+ print('# avr:\t%d' % (sum(nr_regions_dist) / len(nr_regions_dist)))
+ for percentile in percentiles:
+ thres_idx = int(percentile / 100.0 * len(nr_regions_dist))
+ if thres_idx == len(nr_regions_dist):
+ thres_idx -= 1
+ threshold = nr_regions_dist[thres_idx]
+ print('%d\t%d' % (percentile, nr_regions_dist[thres_idx]))
+
+ if args.plot:
+ sys.stdout = orig_stdout
+ tmp_file.flush()
+ tmp_file.close()
+ xlabel = 'runtime (percent)'
+ if nr_regions_sort:
+ xlabel = 'percentile'
+ _dist.plot_dist(tmp_path, args.plot, xlabel,
+ 'number of monitoring target regions')
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/damon/record.py b/tools/damon/record.py
new file mode 100644
index 000000000000..a547d479a103
--- /dev/null
+++ b/tools/damon/record.py
@@ -0,0 +1,212 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Record data access patterns of the target process.
+"""
+
+import argparse
+import copy
+import os
+import signal
+import subprocess
+import time
+
+debugfs_attrs = None
+debugfs_record = None
+debugfs_pids = None
+debugfs_monitor_on = None
+
+def set_target_pid(pid):
+ return subprocess.call('echo %s > %s' % (pid, debugfs_pids), shell=True,
+ executable='/bin/bash')
+
+def turn_damon(on_off):
+ return subprocess.call("echo %s > %s" % (on_off, debugfs_monitor_on),
+ shell=True, executable="/bin/bash")
+
+def is_damon_running():
+ with open(debugfs_monitor_on, 'r') as f:
+ return f.read().strip() == 'on'
+
+def do_record(target, is_target_cmd, attrs, old_attrs):
+ if os.path.isfile(attrs.rfile_path):
+ os.rename(attrs.rfile_path, attrs.rfile_path + '.old')
+
+ if attrs.apply():
+ print('attributes (%s) failed to be applied' % attrs)
+ cleanup_exit(old_attrs, -1)
+ print('# damon attrs: %s' % attrs)
+ if is_target_cmd:
+ p = subprocess.Popen(target, shell=True, executable='/bin/bash')
+ target = p.pid
+ if set_target_pid(target):
+ print('pid setting (%s) failed' % target)
+ cleanup_exit(old_attrs, -2)
+ if turn_damon('on'):
+ print('could not turn on damon' % target)
+ cleanup_exit(old_attrs, -3)
+ if is_target_cmd:
+ p.wait()
+ while True:
+ # damon will turn it off by itself if the target tasks are terminated.
+ if not is_damon_running():
+ break
+ time.sleep(1)
+
+ cleanup_exit(old_attrs, 0)
+
+class Attrs:
+ sample_interval = None
+ aggr_interval = None
+ regions_update_interval = None
+ min_nr_regions = None
+ max_nr_regions = None
+ rbuf_len = None
+ rfile_path = None
+
+ def __init__(self, s, a, r, n, x, l, f):
+ self.sample_interval = s
+ self.aggr_interval = a
+ self.regions_update_interval = r
+ self.min_nr_regions = n
+ self.max_nr_regions = x
+ self.rbuf_len = l
+ self.rfile_path = f
+
+ def __str__(self):
+ return "%s %s %s %s %s %s %s" % (self.sample_interval, self.aggr_interval,
+ self.regions_update_interval, self.min_nr_regions,
+ self.max_nr_regions, self.rbuf_len, self.rfile_path)
+
+ def attr_str(self):
+ return "%s %s %s %s %s " % (self.sample_interval, self.aggr_interval,
+ self.regions_update_interval, self.min_nr_regions,
+ self.max_nr_regions)
+
+ def record_str(self):
+ return '%s %s ' % (self.rbuf_len, self.rfile_path)
+
+ def apply(self):
+ ret = subprocess.call('echo %s > %s' % (self.attr_str(), debugfs_attrs),
+ shell=True, executable='/bin/bash')
+ if ret:
+ return ret
+ return subprocess.call('echo %s > %s' % (self.record_str(),
+ debugfs_record), shell=True, executable='/bin/bash')
+
+def current_attrs():
+ with open(debugfs_attrs, 'r') as f:
+ attrs = f.read().split()
+ attrs = [int(x) for x in attrs]
+
+ with open(debugfs_record, 'r') as f:
+ rattrs = f.read().split()
+ attrs.append(int(rattrs[0]))
+ attrs.append(rattrs[1])
+ return Attrs(*attrs)
+
+def cmd_args_to_attrs(args):
+ "Generate attributes with specified arguments"
+ sample_interval = args.sample
+ aggr_interval = args.aggr
+ regions_update_interval = args.updr
+ min_nr_regions = args.minr
+ max_nr_regions = args.maxr
+ rbuf_len = args.rbuf
+ if not os.path.isabs(args.out):
+ args.out = os.path.join(os.getcwd(), args.out)
+ rfile_path = args.out
+ return Attrs(sample_interval, aggr_interval, regions_update_interval,
+ min_nr_regions, max_nr_regions, rbuf_len, rfile_path)
+
+def cleanup_exit(orig_attrs, exit_code):
+ if is_damon_running():
+ if turn_damon('off'):
+ print('failed to turn damon off!')
+ if orig_attrs:
+ if orig_attrs.apply():
+ print('original attributes (%s) restoration failed!' % orig_attrs)
+ exit(exit_code)
+
+def sighandler(signum, frame):
+ print('\nsignal %s received' % signum)
+ cleanup_exit(orig_attrs, signum)
+
+def chk_update_debugfs(debugfs):
+ global debugfs_attrs
+ global debugfs_record
+ global debugfs_pids
+ global debugfs_monitor_on
+
+ debugfs_damon = os.path.join(debugfs, 'damon')
+ debugfs_attrs = os.path.join(debugfs_damon, 'attrs')
+ debugfs_record = os.path.join(debugfs_damon, 'record')
+ debugfs_pids = os.path.join(debugfs_damon, 'pids')
+ debugfs_monitor_on = os.path.join(debugfs_damon, 'monitor_on')
+
+ if not os.path.isdir(debugfs_damon):
+ print("damon debugfs dir (%s) not found", debugfs_damon)
+ exit(1)
+
+ for f in [debugfs_attrs, debugfs_record, debugfs_pids, debugfs_monitor_on]:
+ if not os.path.isfile(f):
+ print("damon debugfs file (%s) not found" % f)
+ exit(1)
+
+def chk_permission():
+ if os.geteuid() != 0:
+ print("Run as root")
+ exit(1)
+
+def set_argparser(parser):
+ parser.add_argument('target', type=str, metavar='<target>',
+ help='the target command or the pid to record')
+ parser.add_argument('-s', '--sample', metavar='<interval>', type=int,
+ default=5000, help='sampling interval')
+ parser.add_argument('-a', '--aggr', metavar='<interval>', type=int,
+ default=100000, help='aggregate interval')
+ parser.add_argument('-u', '--updr', metavar='<interval>', type=int,
+ default=1000000, help='regions update interval')
+ parser.add_argument('-n', '--minr', metavar='<# regions>', type=int,
+ default=10, help='minimal number of regions')
+ parser.add_argument('-m', '--maxr', metavar='<# regions>', type=int,
+ default=1000, help='maximum number of regions')
+ parser.add_argument('-l', '--rbuf', metavar='<len>', type=int,
+ default=1024*1024, help='length of record result buffer')
+ parser.add_argument('-o', '--out', metavar='<file path>', type=str,
+ default='damon.data', help='output file path')
+ parser.add_argument('-d', '--debugfs', metavar='<debugfs>', type=str,
+ default='/sys/kernel/debug', help='debugfs mounted path')
+
+def main(args=None):
+ global orig_attrs
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ chk_permission()
+ chk_update_debugfs(args.debugfs)
+
+ signal.signal(signal.SIGINT, sighandler)
+ signal.signal(signal.SIGTERM, sighandler)
+ orig_attrs = current_attrs()
+
+ new_attrs = cmd_args_to_attrs(args)
+ target = args.target
+
+ target_fields = target.split()
+ if not subprocess.call('which %s > /dev/null' % target_fields[0],
+ shell=True, executable='/bin/bash'):
+ do_record(target, True, new_attrs, orig_attrs)
+ else:
+ try:
+ pid = int(target)
+ except:
+ print('target \'%s\' is neither a command, nor a pid' % target)
+ exit(1)
+ do_record(target, False, new_attrs, orig_attrs)
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/damon/report.py b/tools/damon/report.py
new file mode 100644
index 000000000000..c661c7b2f1af
--- /dev/null
+++ b/tools/damon/report.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import argparse
+
+import bin2txt
+import heats
+import nr_regions
+import wss
+
+def set_argparser(parser):
+ subparsers = parser.add_subparsers(title='report type', dest='report_type',
+ metavar='<report type>', help='the type of the report to generate')
+ subparsers.required = True
+
+ parser_raw = subparsers.add_parser('raw', help='human readable raw data')
+ bin2txt.set_argparser(parser_raw)
+
+ parser_heats = subparsers.add_parser('heats', help='heats of regions')
+ heats.set_argparser(parser_heats)
+
+ parser_wss = subparsers.add_parser('wss', help='working set size')
+ wss.set_argparser(parser_wss)
+
+ parser_nr_regions = subparsers.add_parser('nr_regions',
+ help='number of regions')
+ nr_regions.set_argparser(parser_nr_regions)
+
+def main(args=None):
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ if args.report_type == 'raw':
+ bin2txt.main(args)
+ elif args.report_type == 'heats':
+ heats.main(args)
+ elif args.report_type == 'wss':
+ wss.main(args)
+ elif args.report_type == 'nr_regions':
+ nr_regions.main(args)
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/damon/wss.py b/tools/damon/wss.py
new file mode 100644
index 000000000000..b43065176cfd
--- /dev/null
+++ b/tools/damon/wss.py
@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"Print out the distribution of the working set sizes of the given trace"
+
+import argparse
+import struct
+import sys
+import tempfile
+
+import _dist
+import _recfile
+
+def set_argparser(parser):
+ parser.add_argument('--input', '-i', type=str, metavar='<file>',
+ default='damon.data', help='input file name')
+ parser.add_argument('--range', '-r', type=int, nargs=3,
+ metavar=('<start>', '<stop>', '<step>'),
+ help='range of wss percentiles to print')
+ parser.add_argument('--sortby', '-s', choices=['time', 'size'],
+ help='the metric to be used for the sort of the working set sizes')
+ parser.add_argument('--plot', '-p', type=str, metavar='<file>',
+ help='plot the distribution to an image file')
+
+def main(args=None):
+ if not args:
+ parser = argparse.ArgumentParser()
+ set_argparser(parser)
+ args = parser.parse_args()
+
+ percentiles = [0, 25, 50, 75, 100]
+
+ file_path = args.input
+ if args.range:
+ percentiles = range(args.range[0], args.range[1], args.range[2])
+ wss_sort = True
+ if args.sortby == 'time':
+ wss_sort = False
+
+ pid_pattern_map = {}
+ with open(file_path, 'rb') as f:
+ _recfile.set_fmt_version(f)
+ start_time = None
+ while True:
+ timebin = f.read(16)
+ if len(timebin) != 16:
+ break
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ for t in range(nr_tasks):
+ pid = _recfile.pid(f)
+ if not pid in pid_pattern_map:
+ pid_pattern_map[pid] = []
+ pid_pattern_map[pid].append(_dist.access_patterns(f))
+
+ orig_stdout = sys.stdout
+ if args.plot:
+ tmp_path = tempfile.mkstemp()[1]
+ tmp_file = open(tmp_path, 'w')
+ sys.stdout = tmp_file
+
+ print('# <percentile> <wss>')
+ for pid in pid_pattern_map.keys():
+ # Skip first 20 snapshots as regions may not adjusted yet.
+ snapshots = pid_pattern_map[pid][20:]
+ wss_dist = []
+ for snapshot in snapshots:
+ wss = 0
+ for p in snapshot:
+ # Ignore regions not accessed
+ if p[1] <= 0:
+ continue
+ wss += p[0]
+ wss_dist.append(wss)
+ if wss_sort:
+ wss_dist.sort(reverse=False)
+
+ print('# pid\t%s' % pid)
+ print('# avr:\t%d' % (sum(wss_dist) / len(wss_dist)))
+ for percentile in percentiles:
+ thres_idx = int(percentile / 100.0 * len(wss_dist))
+ if thres_idx == len(wss_dist):
+ thres_idx -= 1
+ threshold = wss_dist[thres_idx]
+ print('%d\t%d' % (percentile, wss_dist[thres_idx]))
+
+ if args.plot:
+ sys.stdout = orig_stdout
+ tmp_file.flush()
+ tmp_file.close()
+ xlabel = 'runtime (percent)'
+ if wss_sort:
+ xlabel = 'percentile'
+ _dist.plot_dist(tmp_path, args.plot, xlabel,
+ 'working set size (bytes)')
+
+if __name__ == '__main__':
+ main()
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 13/16] Documentation/admin-guide/mm: Add a document for DAMON
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (11 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 12/16] tools: Add a minimal user-space tool for DAMON SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 14/16] mm/damon: Add kunit tests SeongJae Park
` (2 subsequent siblings)
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds a simple document for DAMON under
`Documentation/admin-guide/mm`.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
.../admin-guide/mm/data_access_monitor.rst | 428 ++++++++++++++++++
Documentation/admin-guide/mm/index.rst | 1 +
2 files changed, 429 insertions(+)
create mode 100644 Documentation/admin-guide/mm/data_access_monitor.rst
diff --git a/Documentation/admin-guide/mm/data_access_monitor.rst b/Documentation/admin-guide/mm/data_access_monitor.rst
new file mode 100644
index 000000000000..1d5e18d6ab9e
--- /dev/null
+++ b/Documentation/admin-guide/mm/data_access_monitor.rst
@@ -0,0 +1,428 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+DAMON: Data Access MONitor
+==========================
+
+Introduction
+============
+
+Memory management decisions can be improved if finer data access information is
+available. However, because such finer information usually comes with higher
+overhead, most systems including Linux forgives the potential benefit and rely
+on only coarse information or some light-weight heuristics.
+
+A number of data access pattern awared memory management optimizations
+consistently say the potential benefit is not small (2.55x speedup). However,
+none of those has successfully adopted into into the Linux kernel mainly due to
+the absence of a scalable and efficient data access monitoring mechanism.
+
+DAMON is a data access monitoring subsystem for the problem. It is 1) accurate
+enough to be used for the DRAM level memory management, 2) light-weight enough
+to be applied online, and 3) keeps predefined upper-bound overhead
+regardless of the size of target workloads (thus scalable).
+
+DAMON is implemented as a standalone kernel module and provides several simple
+interfaces. Owing to that, though it has mainly designed for the kernel's
+memory management mechanisms, it can be also used for a wide range of user
+space programs and people.
+
+
+Frequently Asked Questions
+==========================
+
+Q: Why not integrated with perf?
+A: From the perspective of perf like profilers, DAMON can be thought of as a
+data source in kernel, like tracepoints, pressure stall information (psi), or
+idle page tracking. Thus, it can be easily integrated with those. However,
+this patchset doesn't provide a fancy perf integration because current step of
+DAMON development is focused on its core logic only. That said, DAMON already
+provides two interfaces for user space programs, which based on debugfs and
+tracepoint, respectively. Using the tracepoint interface, you can use DAMON
+with perf. This patchset also provides the debugfs interface based user space
+tool for DAMON. It can be used to record, visualize, and analyze data access
+pattern of target processes in a convenient way.
+
+Q: Why a new module, instead of extending perf or other tools?
+A: First, DAMON aims to be used by other programs including the kernel.
+Therefore, having dependency to specific tools like perf is not desirable.
+Second, because it need to be lightweight as much as possible so that it can be
+used online, any unnecessary overhead such as kernel - user space context
+switching cost should be avoided. These are the two most biggest reasons why
+DAMON is implemented in the kernel space. The idle page tracking subsystem
+would be the kernel module that most seems similar to DAMON. However, it's own
+interface is not compatible with DAMON. Also, the internal implementation of
+it has no common part to be reused by DAMON.
+
+Q: Can 'perf mem' provide the data required for DAMON?
+A: On the systems supporting 'perf mem', yes. DAMON is using the PTE Accessed
+bits in low level. Other H/W or S/W features that can be used for the purpose
+could be used. However, as explained with above question, DAMON need to be
+implemented in the kernel space.
+
+
+Expected Use-cases
+==================
+
+A straightforward usecase of DAMON would be the program behavior analysis.
+With the DAMON output, users can confirm whether the program is running as
+intended or not. This will be useful for debuggings and tests of design
+points.
+
+The monitored results can also be useful for counting the dynamic working set
+size of workloads. For the administration of memory overcommitted systems or
+selection of the environments (e.g., containers providing different amount of
+memory) for your workloads, this will be useful.
+
+If you are a programmer, you can optimize your program by managing the memory
+based on the actual data access pattern. For example, you can identify the
+dynamic hotness of your data using DAMON and call ``mlock()`` to keep your hot
+data in DRAM, or call ``madvise()`` with ``MADV_PAGEOUT`` to proactively
+reclaim cold data. Even though your program is guaranteed to not encounter
+memory pressure, you can still improve the performance by applying the DAMON
+outputs for call of ``MADV_HUGEPAGE`` and ``MADV_NOHUGEPAGE``. More creative
+optimizations would be possible. Our evaluations of DAMON includes a
+straightforward optimization using the ``mlock()``. Please refer to the below
+Evaluation section for more detail.
+
+As DAMON incurs very low overhead, such optimizations can be applied not only
+offline, but also online. Also, there is no reason to limit such optimizations
+to the user space. Several parts of the kernel's memory management mechanisms
+could be also optimized using DAMON. The reclamation, the THP (de)promotion
+decisions, and the compaction would be such a candidates.
+
+
+Mechanisms of DAMON
+===================
+
+
+Basic Access Check
+------------------
+
+DAMON basically reports what pages are how frequently accessed. The report is
+passed to users in binary format via a ``result file`` which users can set it's
+path. Note that the frequency is not an absolute number of accesses, but a
+relative frequency among the pages of the target workloads.
+
+Users can also control the resolution of the reports by setting two time
+intervals, ``sampling interval`` and ``aggregation interval``. In detail,
+DAMON checks access to each page per ``sampling interval``, aggregates the
+results (counts the number of the accesses to each page), and reports the
+aggregated results per ``aggregation interval``. For the access check of each
+page, DAMON uses the Accessed bits of PTEs.
+
+This is thus similar to the previously mentioned periodic access checks based
+mechanisms, which overhead is increasing as the size of the target process
+grows.
+
+
+Region Based Sampling
+---------------------
+
+To avoid the unbounded increase of the overhead, DAMON groups a number of
+adjacent pages that assumed to have same access frequencies into a region. As
+long as the assumption (pages in a region have same access frequencies) is
+kept, only one page in the region is required to be checked. Thus, for each
+``sampling interval``, DAMON randomly picks one page in each region and clears
+its Accessed bit. After one more ``sampling interval``, DAMON reads the
+Accessed bit of the page and increases the access frequency of the region if
+the bit has set meanwhile. Therefore, the monitoring overhead is controllable
+by setting the number of regions. DAMON allows users to set the minimal and
+maximum number of regions for the trade-off.
+
+Except the assumption, this is almost same with the above-mentioned
+miniature-like static region based sampling. In other words, this scheme
+cannot preserve the quality of the output if the assumption is not guaranteed.
+
+
+Adaptive Regions Adjustment
+---------------------------
+
+At the beginning of the monitoring, DAMON constructs the initial regions by
+evenly splitting the memory mapped address space of the process into the
+user-specified minimal number of regions. In this initial state, the
+assumption is normally not kept and thus the quality could be low. To keep the
+assumption as much as possible, DAMON adaptively merges and splits each region.
+For each ``aggregation interval``, it compares the access frequencies of
+adjacent regions and merges those if the frequency difference is small. Then,
+after it reports and clears the aggregated access frequency of each region, it
+splits each region into two regions if the total number of regions is smaller
+than the half of the user-specified maximum number of regions.
+
+In this way, DAMON provides its best-effort quality and minimal overhead while
+keeping the bounds users set for their trade-off.
+
+
+Applying Complex and Dynamic Memory Mappings
+--------------------------------------------
+
+Only a number of small parts in the super-huge virtual address space of the
+processes is mapped to physical memory and accessed. Thus, tracking the
+unmapped address regions is just wasteful. However, because DAMON can deal
+with some level of noises using the adaptive regions adjustment mechanism,
+tracking every mapping is not strictly required but could even incur a high
+overhead in somce cases. That said, too huge unmapped areas inside the
+monitoring target should be removed to not take the time for the adaptive
+mechanism.
+
+For the reason, DAMON converts the complex mappings to three distinct regions
+that cover every mapped areas of the address space. Also the two gaps between
+the three regions are the two biggest unmapped areas in the given address
+space. The two biggest unmapped areas might be the gap between the heap and
+the uppermost mmap()-ed region, and the gap between the lowermost mmap()-ed
+region and the stack will be two biggest unmapped regions. Because these gaps
+are exceptionally huge areas in usual address space, excluding these two
+biggest unmapped regions will be sufficient to make a trade-off.
+
+To further minimize dynamic mapping changes applying overhead, DAMON check the
+dynamic memory mapping changes and applies it to the abstracted target area
+only for each of a user-specified time interval (``regions update interval``).
+
+
+``debugfs`` Interface
+=====================
+
+DAMON exports four files, ``attrs``, ``pids``, ``record``, and ``monitor_on``
+under its debugfs directory, ``<debugfs>/damon/``.
+
+Attributes
+----------
+
+Users can read and write the ``sampling interval``, ``aggregation interval``,
+``regions update interval``, and min/max number of monitoring target regions by
+reading from and writing to the ``attrs`` file. For example, below commands
+set those values to 5 ms, 100 ms, 1,000 ms, 10, 1000 and check it again::
+
+ # cd <debugfs>/damon
+ # echo 5000 100000 1000000 10 1000 > attrs
+ # cat attrs
+ 5000 100000 1000000 10 1000
+
+Target PIDs
+-----------
+
+Users can read and write the pids of current monitoring target processes by
+reading from and writing to the ``pids`` file. For example, below commands set
+processes having pids 42 and 4242 as the processes to be monitored and check it
+again::
+
+ # cd <debugfs>/damon
+ # echo 42 4242 > pids
+ # cat pids
+ 42 4242
+
+Note that setting the pids doesn't start the monitoring.
+
+Record
+------
+
+DAMON supports direct monitoring result record feature. The recorded results
+are first written to a buffer and flushed to a file in batch. Users can set
+the size of the buffer and the path to the result file by reading from and
+writing to the ``record`` file. For example, below commands set the buffer to
+be 4 KiB and the result to be saved in ``/damon.data``.
+
+ # cd <debugfs>/damon
+ # echo "4096 /damon.data" > record
+ # cat record
+ 4096 /damon.data
+
+Turning On/Off
+--------------
+
+You can check current status, start and stop the monitoring by reading from and
+writing to the ``monitor_on`` file. Writing ``on`` to the file starts DAMON to
+monitor the target processes with the attributes. Writing ``off`` to the file
+stops DAMON. DAMON also stops if every target processes is terminated.
+Below example commands turn on, off, and check status of DAMON::
+
+ # cd <debugfs>/damon
+ # echo on > monitor_on
+ # echo off > monitor_on
+ # cat monitor_on
+ off
+
+Please note that you cannot write to the ``attrs`` and ``pids`` files while the
+monitoring is turned on. If you write to the files while DAMON is running, an
+error code such as ``-EBUSY`` will be returned.
+
+
+User Space Tool for DAMON
+=========================
+
+There is a user space tool for DAMON, ``/tools/damon/damo``. It provides
+another user interface which more convenient than the debugfs interface.
+Nevertheless, note that it is only aimed to be used for minimal reference of
+the DAMON's debugfs interfaces and for tests of the DAMON itself. Based on the
+debugfs interface, you can create another cool and more convenient user space
+tools.
+
+The interface of the tool is basically subcommand based. You can almost always
+use ``-h`` option to get help of the use of each subcommand. Currently, it
+supports two subcommands, ``record`` and ``report``.
+
+
+Recording Data Access Pattern
+-----------------------------
+
+The ``record`` subcommand records the data access pattern of target process in
+a file (``./damon.data`` by default) using DAMON. You can specifies the target
+as either pid or a command for an execution of the process. Below example
+shows a command target usage::
+
+ # cd <kernel>/tools/damon/
+ # ./damo record "sleep 5"
+
+The tool will execute ``sleep 5`` by itself and record the data access patterns
+of the process. Below example shows a pid target usage::
+
+ # sleep 5 &
+ # ./damo record `pidof sleep`
+
+You can set more detailed attributes and path to the recorded data file using
+optional arguments to the subcommand. Use the ``-h`` option for more help.
+
+
+Analyzing Data Access Pattern
+-----------------------------
+
+The ``report`` subcommand reads a data access pattern record file (if not
+explicitly specified, reads ``./damon.data`` file if exists) and generates
+reports of various types. You can specify what type of report you want using
+sub-subcommand to ``report`` subcommand. For supported types, pass the ``-h``
+option to ``report`` subcommand.
+
+
+raw
+~~~
+
+``raw`` sub-subcommand simply transforms the record, which is storing the data
+access patterns in binary format to human readable text. For example::
+
+ $ ./damo report raw
+ start_time: 193485829398
+ rel time: 0
+ nr_tasks: 1
+ pid: 1348
+ nr_regions: 4
+ 560189609000-56018abce000( 22827008): 0
+ 7fbdff59a000-7fbdffaf1a00( 5601792): 0
+ 7fbdffaf1a00-7fbdffbb5000( 800256): 1
+ 7ffea0dc0000-7ffea0dfd000( 249856): 0
+
+ rel time: 100000731
+ nr_tasks: 1
+ pid: 1348
+ nr_regions: 6
+ 560189609000-56018abce000( 22827008): 0
+ 7fbdff59a000-7fbdff8ce933( 3361075): 0
+ 7fbdff8ce933-7fbdffaf1a00( 2240717): 1
+ 7fbdffaf1a00-7fbdffb66d99( 480153): 0
+ 7fbdffb66d99-7fbdffbb5000( 320103): 1
+ 7ffea0dc0000-7ffea0dfd000( 249856): 0
+
+The first line shows recording started timestamp (nanosecond). Records of data
+access patterns are following this. Each record is sperated by a blank line.
+Each record first specifies the recorded time (``rel time``), number of
+monitored tasks in this record (``nr_tasks``). Multiple number of records of
+data access pattern for each task continue. Each data access pattern for each
+task shows first it's pid (``pid``) and number of monitored virtual address
+regions in this access pattern (``nr_regions``). After that, each line shows
+start/end address, size, and number of monitored accesses to the region for
+each of the regions.
+
+
+heats
+~~~~~
+
+The ``raw`` type shows detailed information but it is exhaustive to manually
+read and analyzed. For the reason, ``heats`` plots the data in heatmap form,
+using time as x-axis, virtual address as y-axis, and access frequency as
+z-axis. Also, users set the resolution and start/end point of each axis via
+optional arguments. For example::
+
+ $ ./damo report heats --tres 3 --ares 3
+ 0 0 0.0
+ 0 7609002 0.0
+ 0 15218004 0.0
+ 66112620851 0 0.0
+ 66112620851 7609002 0.0
+ 66112620851 15218004 0.0
+ 132225241702 0 0.0
+ 132225241702 7609002 0.0
+ 132225241702 15218004 0.0
+
+This command shows the recorded access pattern of the ``sleep`` command using 3
+data points for each of time axis and address axis. Therefore, it shows 9 data
+points in total.
+
+Users can easily converts this text output into heatmap image or other 3D
+representation using various tools such as 'gnuplot'. ``raw`` sub-subcommand
+also provides 'gnuplot' based heatmap image creation. For this, you can use
+``--heatmap`` option. Also, note that because it uses 'gnuplot' internally, it
+will fail if 'gnuplot' is not installed on your system. For example::
+
+ $ ./damo report heats --heatmap heatmap.png
+
+Creates ``heatmap.png`` file containing the heatmap image. It supports
+``pdf``, ``png``, ``jpeg``, and ``svg``.
+
+For proper zoom in / zoom out, you need to see the layout of the record. For
+that, use '--guide' option. If the option is given, it will provide useful
+information about the records in the record file. For example::
+
+ $ ./damo report heats --guide
+ pid:1348
+ time: 193485829398-198337863555 (4852034157)
+ region 0: 00000094564599762944-00000094564622589952 (22827008)
+ region 1: 00000140454009610240-00000140454016012288 (6402048)
+ region 2: 00000140731597193216-00000140731597443072 (249856)
+
+The output shows monitored regions (start and end addresses in byte) and
+monitored time duration (start and end time in nanosecond) of each target task.
+Therefore, it would be wise to plot only each region rather than plotting
+entire address space in one heatmap because the gaps between the regions are so
+huge in this case.
+
+
+wss
+~~~
+
+The ``wss`` type shows the distribution or time-varying working set sizes of
+the recorded workload using the records. For example::
+
+ $ ./damo report wss
+ # <percentile> <wss>
+ # pid 1348
+ # avr: 66228
+ 0 0
+ 25 0
+ 50 0
+ 75 0
+ 100 1920615
+
+Without any option, it shows the distribution of the working set sizes as
+above. Basically it shows 0th, 25th, 50th, 75th, and 100th percentile and
+average of the measured working set sizes in the access pattern records. In
+this case, the working set size was zero for 75th percentile but 1,920,615
+bytes in max and 66,228 in average.
+
+By setting the sort key of the percentile using '--sortby', you can also see
+how the working set size is chronologically changed. For example::
+
+ $ ./damo report wss --sortby time
+ # <percentile> <wss>
+ # pid 1348
+ # avr: 66228
+ 0 0
+ 25 0
+ 50 0
+ 75 0
+ 100 0
+
+The average is still 66,228. And, because we sorted the working set using
+recorded time and the access is very short, we cannot show when the access
+made.
+
+Users can specify the resolution of the distribution (``--range``). It also
+supports 'gnuplot' based simple visualization (``--plot``) of the distribution.
diff --git a/Documentation/admin-guide/mm/index.rst b/Documentation/admin-guide/mm/index.rst
index 11db46448354..d3d0ba373eb6 100644
--- a/Documentation/admin-guide/mm/index.rst
+++ b/Documentation/admin-guide/mm/index.rst
@@ -27,6 +27,7 @@ the Linux memory management.
concepts
cma_debugfs
+ data_access_monitor
hugetlbpage
idle_page_tracking
ksm
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 14/16] mm/damon: Add kunit tests
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (12 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 13/16] Documentation/admin-guide/mm: Add a document " SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 15/16] mm/damon: Add user space selftests SeongJae Park
2020-05-05 11:08 ` [PATCH v10 16/16] MAINTAINERS: Update for DAMON SeongJae Park
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds kunit based unit tests for DAMON.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
mm/Kconfig | 11 +
mm/damon-test.h | 622 ++++++++++++++++++++++++++++++++++++++++++++++++
mm/damon.c | 6 +
3 files changed, 639 insertions(+)
create mode 100644 mm/damon-test.h
diff --git a/mm/Kconfig b/mm/Kconfig
index 9ea49633a6df..81ace52f1c23 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -751,4 +751,15 @@ config DAMON
and 2) sufficiently light-weight so that it can be applied online.
If unsure, say N.
+config DAMON_KUNIT_TEST
+ bool "Test for damon"
+ depends on DAMON=y && KUNIT
+ help
+ This builds the DAMON Kunit test suite.
+
+ For more information on KUnit and unit tests in general, please refer
+ to the KUnit documentation.
+
+ If unsure, say N.
+
endmenu
diff --git a/mm/damon-test.h b/mm/damon-test.h
new file mode 100644
index 000000000000..851c2062a480
--- /dev/null
+++ b/mm/damon-test.h
@@ -0,0 +1,622 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Data Access Monitor Unit Tests
+ *
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All rights reserved.
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#ifdef CONFIG_DAMON_KUNIT_TEST
+
+#ifndef _DAMON_TEST_H
+#define _DAMON_TEST_H
+
+#include <kunit/test.h>
+
+static void damon_test_str_to_pids(struct kunit *test)
+{
+ char *question;
+ int *answers;
+ int expected[] = {12, 35, 46};
+ ssize_t nr_integers = 0, i;
+
+ question = "123";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)1, nr_integers);
+ KUNIT_EXPECT_EQ(test, 123, answers[0]);
+ kfree(answers);
+
+ question = "123abc";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)1, nr_integers);
+ KUNIT_EXPECT_EQ(test, 123, answers[0]);
+ kfree(answers);
+
+ question = "a123";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
+ KUNIT_EXPECT_PTR_EQ(test, answers, (int *)NULL);
+
+ question = "12 35";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)2, nr_integers);
+ for (i = 0; i < nr_integers; i++)
+ KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
+ kfree(answers);
+
+ question = "12 35 46";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)3, nr_integers);
+ for (i = 0; i < nr_integers; i++)
+ KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
+ kfree(answers);
+
+ question = "12 35 abc 46";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)2, nr_integers);
+ for (i = 0; i < 2; i++)
+ KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
+ kfree(answers);
+
+ question = "";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
+ KUNIT_EXPECT_PTR_EQ(test, (int *)NULL, answers);
+ kfree(answers);
+
+ question = "\n";
+ answers = str_to_pids(question, strnlen(question, 128), &nr_integers);
+ KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
+ KUNIT_EXPECT_PTR_EQ(test, (int *)NULL, answers);
+ kfree(answers);
+}
+
+static void damon_test_regions(struct kunit *test)
+{
+ struct damon_region *r;
+ struct damon_task *t;
+
+ r = damon_new_region(&damon_user_ctx, 1, 2);
+ KUNIT_EXPECT_EQ(test, 1ul, r->vm_start);
+ KUNIT_EXPECT_EQ(test, 2ul, r->vm_end);
+ KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
+
+ t = damon_new_task(42);
+ KUNIT_EXPECT_EQ(test, 0u, nr_damon_regions(t));
+
+ damon_add_region(r, t);
+ KUNIT_EXPECT_EQ(test, 1u, nr_damon_regions(t));
+
+ damon_del_region(r);
+ KUNIT_EXPECT_EQ(test, 0u, nr_damon_regions(t));
+
+ damon_free_task(t);
+}
+
+static void damon_test_tasks(struct kunit *test)
+{
+ struct damon_ctx *c = &damon_user_ctx;
+ struct damon_task *t;
+
+ t = damon_new_task(42);
+ KUNIT_EXPECT_EQ(test, 42, t->pid);
+ KUNIT_EXPECT_EQ(test, 0u, nr_damon_tasks(c));
+
+ damon_add_task(&damon_user_ctx, t);
+ KUNIT_EXPECT_EQ(test, 1u, nr_damon_tasks(c));
+
+ damon_destroy_task(t);
+ KUNIT_EXPECT_EQ(test, 0u, nr_damon_tasks(c));
+}
+
+static void damon_test_set_pids(struct kunit *test)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ int pids[] = {1, 2, 3};
+ char buf[64];
+
+ damon_set_pids(ctx, pids, 3);
+ damon_sprint_pids(ctx, buf, 64);
+ KUNIT_EXPECT_STREQ(test, (char *)buf, "1 2 3\n");
+
+ damon_set_pids(ctx, NULL, 0);
+ damon_sprint_pids(ctx, buf, 64);
+ KUNIT_EXPECT_STREQ(test, (char *)buf, "\n");
+
+ damon_set_pids(ctx, (int []){1, 2}, 2);
+ damon_sprint_pids(ctx, buf, 64);
+ KUNIT_EXPECT_STREQ(test, (char *)buf, "1 2\n");
+
+ damon_set_pids(ctx, (int []){2}, 1);
+ damon_sprint_pids(ctx, buf, 64);
+ KUNIT_EXPECT_STREQ(test, (char *)buf, "2\n");
+
+ damon_set_pids(ctx, NULL, 0);
+ damon_sprint_pids(ctx, buf, 64);
+ KUNIT_EXPECT_STREQ(test, (char *)buf, "\n");
+}
+
+/*
+ * Test damon_three_regions_in_vmas() function
+ *
+ * DAMON converts the complex and dynamic memory mappings of each target task
+ * to three discontiguous regions which cover every mapped areas. However, the
+ * three regions should not include the two biggest unmapped areas in the
+ * original mapping, because the two biggest areas are normally the areas
+ * between 1) heap and the mmap()-ed regions, and 2) the mmap()-ed regions and
+ * stack. Because these two unmapped areas are very huge but obviously never
+ * accessed, covering the region is just a waste.
+ *
+ * 'damon_three_regions_in_vmas() receives an address space of a process. It
+ * first identifies the start of mappings, end of mappings, and the two biggest
+ * unmapped areas. After that, based on the information, it constructs the
+ * three regions and returns. For more detail, refer to the comment of
+ * 'damon_init_regions_of()' function definition in 'mm/damon.c' file.
+ *
+ * For example, suppose virtual address ranges of 10-20, 20-25, 200-210,
+ * 210-220, 300-305, and 307-330 (Other comments represent this mappings in
+ * more short form: 10-20-25, 200-210-220, 300-305, 307-330) of a process are
+ * mapped. To cover every mappings, the three regions should start with 10,
+ * and end with 305. The process also has three unmapped areas, 25-200,
+ * 220-300, and 305-307. Among those, 25-200 and 220-300 are the biggest two
+ * unmapped areas, and thus it should be converted to three regions of 10-25,
+ * 200-220, and 300-330.
+ */
+static void damon_test_three_regions_in_vmas(struct kunit *test)
+{
+ struct region regions[3] = {0,};
+ /* 10-20-25, 200-210-220, 300-305, 307-330 */
+ struct vm_area_struct vmas[] = {
+ (struct vm_area_struct) {.vm_start = 10, .vm_end = 20},
+ (struct vm_area_struct) {.vm_start = 20, .vm_end = 25},
+ (struct vm_area_struct) {.vm_start = 200, .vm_end = 210},
+ (struct vm_area_struct) {.vm_start = 210, .vm_end = 220},
+ (struct vm_area_struct) {.vm_start = 300, .vm_end = 305},
+ (struct vm_area_struct) {.vm_start = 307, .vm_end = 330},
+ };
+ vmas[0].vm_next = &vmas[1];
+ vmas[1].vm_next = &vmas[2];
+ vmas[2].vm_next = &vmas[3];
+ vmas[3].vm_next = &vmas[4];
+ vmas[4].vm_next = &vmas[5];
+ vmas[5].vm_next = NULL;
+
+ damon_three_regions_in_vmas(&vmas[0], regions);
+
+ KUNIT_EXPECT_EQ(test, 10ul, regions[0].start);
+ KUNIT_EXPECT_EQ(test, 25ul, regions[0].end);
+ KUNIT_EXPECT_EQ(test, 200ul, regions[1].start);
+ KUNIT_EXPECT_EQ(test, 220ul, regions[1].end);
+ KUNIT_EXPECT_EQ(test, 300ul, regions[2].start);
+ KUNIT_EXPECT_EQ(test, 330ul, regions[2].end);
+}
+
+/* Clean up global state of damon */
+static void damon_cleanup_global_state(void)
+{
+ struct damon_task *t, *next;
+
+ damon_for_each_task_safe(&damon_user_ctx, t, next)
+ damon_destroy_task(t);
+
+ damon_user_ctx.rbuf_offset = 0;
+}
+
+/*
+ * Test kdamond_reset_aggregated()
+ *
+ * DAMON checks access to each region and aggregates this information as the
+ * access frequency of each region. In detail, it increases '->nr_accesses' of
+ * regions that an access has confirmed. 'kdamond_reset_aggregated()' flushes
+ * the aggregated information ('->nr_accesses' of each regions) to the result
+ * buffer. As a result of the flushing, the '->nr_accesses' of regions are
+ * initialized to zero.
+ */
+static void damon_test_aggregate(struct kunit *test)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ int pids[] = {1, 2, 3};
+ unsigned long saddr[][3] = {{10, 20, 30}, {5, 42, 49}, {13, 33, 55} };
+ unsigned long eaddr[][3] = {{15, 27, 40}, {31, 45, 55}, {23, 44, 66} };
+ unsigned long accesses[][3] = {{42, 95, 84}, {10, 20, 30}, {0, 1, 2} };
+ struct damon_task *t;
+ struct damon_region *r;
+ int it, ir;
+ ssize_t sz, sr, sp;
+
+ damon_set_recording(ctx, 256, "damon.data");
+ damon_set_pids(ctx, pids, 3);
+
+ it = 0;
+ damon_for_each_task(ctx, t) {
+ for (ir = 0; ir < 3; ir++) {
+ r = damon_new_region(ctx,
+ saddr[it][ir], eaddr[it][ir]);
+ r->nr_accesses = accesses[it][ir];
+ damon_add_region(r, t);
+ }
+ it++;
+ }
+ kdamond_reset_aggregated(ctx);
+ it = 0;
+ damon_for_each_task(ctx, t) {
+ ir = 0;
+ /* '->nr_accesses' should be zeroed */
+ damon_for_each_region(r, t) {
+ KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
+ ir++;
+ }
+ /* regions should be preserved */
+ KUNIT_EXPECT_EQ(test, 3, ir);
+ it++;
+ }
+ /* tasks also should be preserved */
+ KUNIT_EXPECT_EQ(test, 3, it);
+
+ /* The aggregated information should be written in the buffer */
+ sr = sizeof(r->vm_start) + sizeof(r->vm_end) + sizeof(r->nr_accesses);
+ sp = sizeof(t->pid) + sizeof(unsigned int) + 3 * sr;
+ sz = sizeof(struct timespec64) + sizeof(unsigned int) + 3 * sp;
+ KUNIT_EXPECT_EQ(test, (unsigned int)sz, ctx->rbuf_offset);
+
+ damon_set_recording(ctx, 0, "damon.data");
+ damon_cleanup_global_state();
+}
+
+static void damon_test_write_rbuf(struct kunit *test)
+{
+ struct damon_ctx *ctx = &damon_user_ctx;
+ char *data;
+
+ damon_set_recording(&damon_user_ctx, 256, "damon.data");
+
+ data = "hello";
+ damon_write_rbuf(ctx, data, strnlen(data, 256));
+ KUNIT_EXPECT_EQ(test, ctx->rbuf_offset, 5u);
+
+ damon_write_rbuf(ctx, data, 0);
+ KUNIT_EXPECT_EQ(test, ctx->rbuf_offset, 5u);
+
+ KUNIT_EXPECT_STREQ(test, (char *)ctx->rbuf, data);
+ damon_set_recording(&damon_user_ctx, 0, "damon.data");
+}
+
+static struct damon_region *__nth_region_of(struct damon_task *t, int idx)
+{
+ struct damon_region *r;
+ unsigned int i = 0;
+
+ damon_for_each_region(r, t) {
+ if (i++ == idx)
+ return r;
+ }
+
+ return NULL;
+}
+
+/*
+ * Test 'damon_apply_three_regions()'
+ *
+ * test kunit object
+ * regions an array containing start/end addresses of current
+ * monitoring target regions
+ * nr_regions the number of the addresses in 'regions'
+ * three_regions The three regions that need to be applied now
+ * expected start/end addresses of monitoring target regions that
+ * 'three_regions' are applied
+ * nr_expected the number of addresses in 'expected'
+ *
+ * The memory mapping of the target processes changes dynamically. To follow
+ * the change, DAMON periodically reads the mappings, simplifies it to the
+ * three regions, and updates the monitoring target regions to fit in the three
+ * regions. The update of current target regions is the role of
+ * 'damon_apply_three_regions()'.
+ *
+ * This test passes the given target regions and the new three regions that
+ * need to be applied to the function and check whether it updates the regions
+ * as expected.
+ */
+static void damon_do_test_apply_three_regions(struct kunit *test,
+ unsigned long *regions, int nr_regions,
+ struct region *three_regions,
+ unsigned long *expected, int nr_expected)
+{
+ struct damon_task *t;
+ struct damon_region *r;
+ int i;
+
+ t = damon_new_task(42);
+ for (i = 0; i < nr_regions / 2; i++) {
+ r = damon_new_region(&damon_user_ctx,
+ regions[i * 2], regions[i * 2 + 1]);
+ damon_add_region(r, t);
+ }
+ damon_add_task(&damon_user_ctx, t);
+
+ damon_apply_three_regions(&damon_user_ctx, t, three_regions);
+
+ for (i = 0; i < nr_expected / 2; i++) {
+ r = __nth_region_of(t, i);
+ KUNIT_EXPECT_EQ(test, r->vm_start, expected[i * 2]);
+ KUNIT_EXPECT_EQ(test, r->vm_end, expected[i * 2 + 1]);
+ }
+
+ damon_cleanup_global_state();
+}
+
+/*
+ * This function test most common case where the three big regions are only
+ * slightly changed. Target regions should adjust their boundary (10-20-30,
+ * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
+ * regions (57-79) that now out of the three regions.
+ */
+static void damon_test_apply_three_regions1(struct kunit *test)
+{
+ /* 10-20-30, 50-55-57-59, 70-80-90-100 */
+ unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
+ 70, 80, 80, 90, 90, 100};
+ /* 5-27, 45-55, 73-104 */
+ struct region new_three_regions[3] = {
+ (struct region){.start = 5, .end = 27},
+ (struct region){.start = 45, .end = 55},
+ (struct region){.start = 73, .end = 104} };
+ /* 5-20-27, 45-55, 73-80-90-104 */
+ unsigned long expected[] = {5, 20, 20, 27, 45, 55,
+ 73, 80, 80, 90, 90, 104};
+
+ damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
+ new_three_regions, expected, ARRAY_SIZE(expected));
+}
+
+/*
+ * Test slightly bigger change. Similar to above, but the second big region
+ * now require two target regions (50-55, 57-59) to be removed.
+ */
+static void damon_test_apply_three_regions2(struct kunit *test)
+{
+ /* 10-20-30, 50-55-57-59, 70-80-90-100 */
+ unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
+ 70, 80, 80, 90, 90, 100};
+ /* 5-27, 56-57, 65-104 */
+ struct region new_three_regions[3] = {
+ (struct region){.start = 5, .end = 27},
+ (struct region){.start = 56, .end = 57},
+ (struct region){.start = 65, .end = 104} };
+ /* 5-20-27, 56-57, 65-80-90-104 */
+ unsigned long expected[] = {5, 20, 20, 27, 56, 57,
+ 65, 80, 80, 90, 90, 104};
+
+ damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
+ new_three_regions, expected, ARRAY_SIZE(expected));
+}
+
+/*
+ * Test a big change. The second big region has totally freed and mapped to
+ * different area (50-59 -> 61-63). The target regions which were in the old
+ * second big region (50-55-57-59) should be removed and new target region
+ * covering the second big region (61-63) should be created.
+ */
+static void damon_test_apply_three_regions3(struct kunit *test)
+{
+ /* 10-20-30, 50-55-57-59, 70-80-90-100 */
+ unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
+ 70, 80, 80, 90, 90, 100};
+ /* 5-27, 61-63, 65-104 */
+ struct region new_three_regions[3] = {
+ (struct region){.start = 5, .end = 27},
+ (struct region){.start = 61, .end = 63},
+ (struct region){.start = 65, .end = 104} };
+ /* 5-20-27, 61-63, 65-80-90-104 */
+ unsigned long expected[] = {5, 20, 20, 27, 61, 63,
+ 65, 80, 80, 90, 90, 104};
+
+ damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
+ new_three_regions, expected, ARRAY_SIZE(expected));
+}
+
+/*
+ * Test another big change. Both of the second and third big regions (50-59
+ * and 70-100) has totally freed and mapped to different area (30-32 and
+ * 65-68). The target regions which were in the old second and third big
+ * regions should now be removed and new target regions covering the new second
+ * and third big regions should be crated.
+ */
+static void damon_test_apply_three_regions4(struct kunit *test)
+{
+ /* 10-20-30, 50-55-57-59, 70-80-90-100 */
+ unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
+ 70, 80, 80, 90, 90, 100};
+ /* 5-7, 30-32, 65-68 */
+ struct region new_three_regions[3] = {
+ (struct region){.start = 5, .end = 7},
+ (struct region){.start = 30, .end = 32},
+ (struct region){.start = 65, .end = 68} };
+ /* expect 5-7, 30-32, 65-68 */
+ unsigned long expected[] = {5, 7, 30, 32, 65, 68};
+
+ damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
+ new_three_regions, expected, ARRAY_SIZE(expected));
+}
+
+static void damon_test_split_evenly(struct kunit *test)
+{
+ struct damon_ctx *c = &damon_user_ctx;
+ struct damon_task *t;
+ struct damon_region *r;
+ unsigned long i;
+
+ KUNIT_EXPECT_EQ(test, damon_split_region_evenly(c, NULL, 5), -EINVAL);
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 0, 100);
+ KUNIT_EXPECT_EQ(test, damon_split_region_evenly(c, r, 0), -EINVAL);
+
+ damon_add_region(r, t);
+ KUNIT_EXPECT_EQ(test, damon_split_region_evenly(c, r, 10), 0);
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 10u);
+
+ i = 0;
+ damon_for_each_region(r, t) {
+ KUNIT_EXPECT_EQ(test, r->vm_start, i++ * 10);
+ KUNIT_EXPECT_EQ(test, r->vm_end, i * 10);
+ }
+ damon_free_task(t);
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 5, 59);
+ damon_add_region(r, t);
+ KUNIT_EXPECT_EQ(test, damon_split_region_evenly(c, r, 5), 0);
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 5u);
+
+ i = 0;
+ damon_for_each_region(r, t) {
+ if (i == 4)
+ break;
+ KUNIT_EXPECT_EQ(test, r->vm_start, 5 + 10 * i++);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 5 + 10 * i);
+ }
+ KUNIT_EXPECT_EQ(test, r->vm_start, 5 + 10 * i);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 59ul);
+ damon_free_task(t);
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 5, 6);
+ damon_add_region(r, t);
+ KUNIT_EXPECT_EQ(test, damon_split_region_evenly(c, r, 2), -EINVAL);
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 1u);
+
+ damon_for_each_region(r, t) {
+ KUNIT_EXPECT_EQ(test, r->vm_start, 5ul);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 6ul);
+ }
+ damon_free_task(t);
+}
+
+static void damon_test_split_at(struct kunit *test)
+{
+ struct damon_task *t;
+ struct damon_region *r;
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 0, 100);
+ damon_add_region(r, t);
+ damon_split_region_at(&damon_user_ctx, r, 25);
+ KUNIT_EXPECT_EQ(test, r->vm_start, 0ul);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 25ul);
+
+ r = damon_next_region(r);
+ KUNIT_EXPECT_EQ(test, r->vm_start, 25ul);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 100ul);
+
+ damon_free_task(t);
+}
+
+static void damon_test_merge_two(struct kunit *test)
+{
+ struct damon_task *t;
+ struct damon_region *r, *r2, *r3;
+ int i;
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 0, 100);
+ r->nr_accesses = 10;
+ damon_add_region(r, t);
+ r2 = damon_new_region(&damon_user_ctx, 100, 300);
+ r2->nr_accesses = 20;
+ damon_add_region(r2, t);
+
+ damon_merge_two_regions(r, r2);
+ KUNIT_EXPECT_EQ(test, r->vm_start, 0ul);
+ KUNIT_EXPECT_EQ(test, r->vm_end, 300ul);
+ KUNIT_EXPECT_EQ(test, r->nr_accesses, 16u);
+
+ i = 0;
+ damon_for_each_region(r3, t) {
+ KUNIT_EXPECT_PTR_EQ(test, r, r3);
+ i++;
+ }
+ KUNIT_EXPECT_EQ(test, i, 1);
+
+ damon_free_task(t);
+}
+
+static void damon_test_merge_regions_of(struct kunit *test)
+{
+ struct damon_task *t;
+ struct damon_region *r;
+ unsigned long sa[] = {0, 100, 114, 122, 130, 156, 170, 184};
+ unsigned long ea[] = {100, 112, 122, 130, 156, 170, 184, 230};
+ unsigned int nrs[] = {0, 0, 10, 10, 20, 30, 1, 2};
+
+ unsigned long saddrs[] = {0, 114, 130, 156, 170};
+ unsigned long eaddrs[] = {112, 130, 156, 170, 230};
+ int i;
+
+ t = damon_new_task(42);
+ for (i = 0; i < ARRAY_SIZE(sa); i++) {
+ r = damon_new_region(&damon_user_ctx, sa[i], ea[i]);
+ r->nr_accesses = nrs[i];
+ damon_add_region(r, t);
+ }
+
+ damon_merge_regions_of(t, 9);
+ /* 0-112, 114-130, 130-156, 156-170 */
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 5u);
+ for (i = 0; i < 5; i++) {
+ r = __nth_region_of(t, i);
+ KUNIT_EXPECT_EQ(test, r->vm_start, saddrs[i]);
+ KUNIT_EXPECT_EQ(test, r->vm_end, eaddrs[i]);
+ }
+ damon_free_task(t);
+}
+
+static void damon_test_split_regions_of(struct kunit *test)
+{
+ struct damon_task *t;
+ struct damon_region *r;
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 0, 22);
+ damon_add_region(r, t);
+ damon_split_regions_of(&damon_user_ctx, t, 2);
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 2u);
+ damon_free_task(t);
+
+ t = damon_new_task(42);
+ r = damon_new_region(&damon_user_ctx, 0, 220);
+ damon_add_region(r, t);
+ damon_split_regions_of(&damon_user_ctx, t, 4);
+ KUNIT_EXPECT_EQ(test, nr_damon_regions(t), 4u);
+ damon_free_task(t);
+}
+
+static struct kunit_case damon_test_cases[] = {
+ KUNIT_CASE(damon_test_str_to_pids),
+ KUNIT_CASE(damon_test_tasks),
+ KUNIT_CASE(damon_test_regions),
+ KUNIT_CASE(damon_test_set_pids),
+ KUNIT_CASE(damon_test_three_regions_in_vmas),
+ KUNIT_CASE(damon_test_aggregate),
+ KUNIT_CASE(damon_test_write_rbuf),
+ KUNIT_CASE(damon_test_apply_three_regions1),
+ KUNIT_CASE(damon_test_apply_three_regions2),
+ KUNIT_CASE(damon_test_apply_three_regions3),
+ KUNIT_CASE(damon_test_apply_three_regions4),
+ KUNIT_CASE(damon_test_split_evenly),
+ KUNIT_CASE(damon_test_split_at),
+ KUNIT_CASE(damon_test_merge_two),
+ KUNIT_CASE(damon_test_merge_regions_of),
+ KUNIT_CASE(damon_test_split_regions_of),
+ {},
+};
+
+static struct kunit_suite damon_test_suite = {
+ .name = "damon",
+ .test_cases = damon_test_cases,
+};
+kunit_test_suite(damon_test_suite);
+
+#endif /* _DAMON_TEST_H */
+
+#endif /* CONFIG_DAMON_KUNIT_TEST */
diff --git a/mm/damon.c b/mm/damon.c
index 9f7d173eca3b..cff27cb9c0e0 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -25,7 +25,11 @@
#include <trace/events/damon.h>
/* Minimal region size. Every damon_region is aligned by this. */
+#ifndef CONFIG_DAMON_KUNIT_TEST
#define MIN_REGION PAGE_SIZE
+#else
+#define MIN_REGION 1
+#endif
#define damon_get_task_struct(t) \
(get_pid_task(find_vpid(t->pid), PIDTYPE_PID))
@@ -1496,3 +1500,5 @@ module_exit(damon_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("SeongJae Park <sjpark@amazon.de>");
MODULE_DESCRIPTION("DAMON: Data Access MONitor");
+
+#include "damon-test.h"
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 15/16] mm/damon: Add user space selftests
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (13 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 14/16] mm/damon: Add kunit tests SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
2020-05-05 11:08 ` [PATCH v10 16/16] MAINTAINERS: Update for DAMON SeongJae Park
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit adds a simple user space tests for DAMON. The tests are
using kselftest framework.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
tools/testing/selftests/damon/Makefile | 7 +
.../selftests/damon/_chk_dependency.sh | 28 ++++
tools/testing/selftests/damon/_chk_record.py | 108 ++++++++++++++
.../testing/selftests/damon/debugfs_attrs.sh | 139 ++++++++++++++++++
.../testing/selftests/damon/debugfs_record.sh | 50 +++++++
5 files changed, 332 insertions(+)
create mode 100644 tools/testing/selftests/damon/Makefile
create mode 100644 tools/testing/selftests/damon/_chk_dependency.sh
create mode 100644 tools/testing/selftests/damon/_chk_record.py
create mode 100755 tools/testing/selftests/damon/debugfs_attrs.sh
create mode 100755 tools/testing/selftests/damon/debugfs_record.sh
diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile
new file mode 100644
index 000000000000..cfd5393a4639
--- /dev/null
+++ b/tools/testing/selftests/damon/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for damon selftests
+
+TEST_FILES = _chk_dependency.sh _chk_record_file.py
+TEST_PROGS = debugfs_attrs.sh debugfs_record.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/damon/_chk_dependency.sh b/tools/testing/selftests/damon/_chk_dependency.sh
new file mode 100644
index 000000000000..814dcadd5e96
--- /dev/null
+++ b/tools/testing/selftests/damon/_chk_dependency.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+DBGFS=/sys/kernel/debug/damon
+
+if [ $EUID -ne 0 ];
+then
+ echo "Run as root"
+ exit $ksft_skip
+fi
+
+if [ ! -d $DBGFS ]
+then
+ echo "$DBGFS not found"
+ exit $ksft_skip
+fi
+
+for f in attrs record pids monitor_on
+do
+ if [ ! -f "$DBGFS/$f" ]
+ then
+ echo "$f not found"
+ exit 1
+ fi
+done
diff --git a/tools/testing/selftests/damon/_chk_record.py b/tools/testing/selftests/damon/_chk_record.py
new file mode 100644
index 000000000000..5cfcf4161404
--- /dev/null
+++ b/tools/testing/selftests/damon/_chk_record.py
@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"Check whether the DAMON record file is valid"
+
+import argparse
+import struct
+import sys
+
+fmt_version = 0
+
+def set_fmt_version(f):
+ global fmt_version
+
+ mark = f.read(16)
+ if mark == b'damon_recfmt_ver':
+ fmt_version = struct.unpack('i', f.read(4))[0]
+ else:
+ fmt_version = 0
+ f.seek(0)
+ return fmt_version
+
+def read_pid(f):
+ if fmt_version == 0:
+ pid = struct.unpack('L', f.read(8))[0]
+ else:
+ pid = struct.unpack('i', f.read(4))[0]
+def err_percent(val, expected):
+ return abs(val - expected) / expected * 100
+
+def chk_task_info(f):
+ pid = read_pid(f)
+ nr_regions = struct.unpack('I', f.read(4))[0]
+
+ if nr_regions > max_nr_regions:
+ print('too many regions: %d > %d' % (nr_regions, max_nr_regions))
+ exit(1)
+
+ nr_gaps = 0
+ eaddr = 0
+ for r in range(nr_regions):
+ saddr = struct.unpack('L', f.read(8))[0]
+ if eaddr and saddr != eaddr:
+ nr_gaps += 1
+ eaddr = struct.unpack('L', f.read(8))[0]
+ nr_accesses = struct.unpack('I', f.read(4))[0]
+
+ if saddr >= eaddr:
+ print('wrong region [%d,%d)' % (saddr, eaddr))
+ exit(1)
+
+ max_nr_accesses = aint / sint
+ if nr_accesses > max_nr_accesses:
+ if err_percent(nr_accesses, max_nr_accesses) > 15:
+ print('too high nr_access: expected %d but %d' %
+ (max_nr_accesses, nr_accesses))
+ exit(1)
+ if nr_gaps != 2:
+ print('number of gaps are not two but %d' % nr_gaps)
+ exit(1)
+
+def parse_time_us(bindat):
+ sec = struct.unpack('l', bindat[0:8])[0]
+ nsec = struct.unpack('l', bindat[8:16])[0]
+ return (sec * 1000000000 + nsec) / 1000
+
+def main():
+ global sint
+ global aint
+ global min_nr
+ global max_nr_regions
+
+ parser = argparse.ArgumentParser()
+ parser.add_argument('file', metavar='<file>',
+ help='path to the record file')
+ parser.add_argument('--attrs', metavar='<attrs>',
+ default='5000 100000 1000000 10 1000',
+ help='content of debugfs attrs file')
+ args = parser.parse_args()
+ file_path = args.file
+ attrs = [int(x) for x in args.attrs.split()]
+ sint, aint, rint, min_nr, max_nr_regions = attrs
+
+ with open(file_path, 'rb') as f:
+ set_fmt_version(f)
+ last_aggr_time = None
+ while True:
+ timebin = f.read(16)
+ if len(timebin) != 16:
+ break
+
+ now = parse_time_us(timebin)
+ if not last_aggr_time:
+ last_aggr_time = now
+ else:
+ error = err_percent(now - last_aggr_time, aint)
+ if error > 15:
+ print('wrong aggr interval: expected %d, but %d' %
+ (aint, now - last_aggr_time))
+ exit(1)
+ last_aggr_time = now
+
+ nr_tasks = struct.unpack('I', f.read(4))[0]
+ for t in range(nr_tasks):
+ chk_task_info(f)
+
+if __name__ == '__main__':
+ main()
diff --git a/tools/testing/selftests/damon/debugfs_attrs.sh b/tools/testing/selftests/damon/debugfs_attrs.sh
new file mode 100755
index 000000000000..d5188b0f71b1
--- /dev/null
+++ b/tools/testing/selftests/damon/debugfs_attrs.sh
@@ -0,0 +1,139 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+source ./_chk_dependency.sh
+
+# Test attrs file
+file="$DBGFS/attrs"
+
+ORIG_CONTENT=$(cat $file)
+
+echo 1 2 3 4 5 > $file
+if [ $? -ne 0 ]
+then
+ echo "$file write failed"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo 1 2 3 4 > $file
+if [ $? -eq 0 ]
+then
+ echo "$file write success (should failed)"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+CONTENT=$(cat $file)
+if [ "$CONTENT" != "1 2 3 4 5" ]
+then
+ echo "$file not written"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo $ORIG_CONTENT > $file
+
+# Test record file
+file="$DBGFS/record"
+
+ORIG_CONTENT=$(cat $file)
+
+echo "4242 foo.bar" > $file
+if [ $? -ne 0 ]
+then
+ echo "$file writing sane input failed"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo abc 2 3 > $file
+if [ $? -eq 0 ]
+then
+ echo "$file writing insane input 1 success (should failed)"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo 123 > $file
+if [ $? -eq 0 ]
+then
+ echo "$file writing insane input 2 success (should failed)"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+CONTENT=$(cat $file)
+if [ "$CONTENT" != "4242 foo.bar" ]
+then
+ echo "$file not written"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo "0 null" > $file
+if [ $? -ne 0 ]
+then
+ echo "$file disabling write fail"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+CONTENT=$(cat $file)
+if [ "$CONTENT" != "0 null" ]
+then
+ echo "$file not disabled"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo "4242 foo.bar" > $file
+if [ $? -ne 0 ]
+then
+ echo "$file writing sane data again fail"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo $ORIG_CONTENT > $file
+
+# Test pids file
+file="$DBGFS/pids"
+
+ORIG_CONTENT=$(cat $file)
+
+echo "1 2 3 4" > $file
+if [ $? -ne 0 ]
+then
+ echo "$file write fail"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo "1 2 abc 4" > $file
+if [ $? -ne 0 ]
+then
+ echo "$file write fail"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo abc 2 3 > $file
+if [ $? -eq 0 ]
+then
+ echo "$file write success (should failed)"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+CONTENT=$(cat $file)
+if [ "$CONTENT" != "1 2" ]
+then
+ echo "$file not written"
+ echo $ORIG_CONTENT > $file
+ exit 1
+fi
+
+echo $ORIG_CONTENT > $file
+
+echo "PASS"
diff --git a/tools/testing/selftests/damon/debugfs_record.sh b/tools/testing/selftests/damon/debugfs_record.sh
new file mode 100755
index 000000000000..fa9e07eea258
--- /dev/null
+++ b/tools/testing/selftests/damon/debugfs_record.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+source ./_chk_dependency.sh
+
+restore_attrs()
+{
+ echo $ORIG_ATTRS > $DBGFS/attrs
+ echo $ORIG_PIDS > $DBGFS/pids
+ echo $ORIG_RECORD > $DBGFS/record
+}
+
+ORIG_ATTRS=$(cat $DBGFS/attrs)
+ORIG_PIDS=$(cat $DBGFS/pids)
+ORIG_RECORD=$(cat $DBGFS/record)
+
+rfile=$pwd/damon.data
+
+rm -f $rfile
+ATTRS="5000 100000 1000000 10 1000"
+echo $ATTRS > $DBGFS/attrs
+echo 4096 $rfile > $DBGFS/record
+sleep 5 &
+echo $(pidof sleep) > $DBGFS/pids
+echo on > $DBGFS/monitor_on
+sleep 0.5
+killall sleep
+echo off > $DBGFS/monitor_on
+
+sync
+
+if [ ! -f $rfile ]
+then
+ echo "record file not made"
+ restore_attrs
+
+ exit 1
+fi
+
+python3 ./_chk_record.py $rfile --attrs "$ATTRS"
+if [ $? -ne 0 ]
+then
+ echo "record file is wrong"
+ restore_attrs
+ exit 1
+fi
+
+rm -f $rfile
+restore_attrs
+echo "PASS"
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v10 16/16] MAINTAINERS: Update for DAMON
2020-05-05 11:07 [PATCH v10 00/16] Introduce Data Access MONitor (DAMON) SeongJae Park
` (14 preceding siblings ...)
2020-05-05 11:08 ` [PATCH v10 15/16] mm/damon: Add user space selftests SeongJae Park
@ 2020-05-05 11:08 ` SeongJae Park
15 siblings, 0 replies; 18+ messages in thread
From: SeongJae Park @ 2020-05-05 11:08 UTC (permalink / raw)
To: akpm
Cc: SeongJae Park, Jonathan.Cameron, aarcange, acme,
alexander.shishkin, amit, benh, brendan.d.gregg, brendanhiggins,
cai, colin.king, corbet, dwmw, irogers, jolsa, kirill,
mark.rutland, mgorman, minchan, mingo, namhyung, peterz, rdunlap,
riel, rientjes, rostedt, sblbir, shakeelb, shuah, sj38.park, snu,
vbabka, vdavydov.dev, yang.shi, ying.huang, linux-damon,
linux-mm, linux-doc, linux-kernel
From: SeongJae Park <sjpark@amazon.de>
This commit updates MAINTAINERS file for DAMON related files.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
MAINTAINERS | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5a5332b3591d..cb4a7fa3cdfe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4661,6 +4661,18 @@ F: net/ax25/ax25_out.c
F: net/ax25/ax25_timer.c
F: net/ax25/sysctl_net_ax25.c
+DATA ACCESS MONITOR
+M: SeongJae Park <sjpark@amazon.de>
+L: linux-mm@kvack.org
+S: Maintained
+F: Documentation/admin-guide/mm/data_access_monitor.rst
+F: include/linux/damon.h
+F: include/trace/events/damon.h
+F: mm/damon-test.h
+F: mm/damon.c
+F: tools/damon/*
+F: tools/testing/selftests/damon/*
+
DAVICOM FAST ETHERNET (DMFE) NETWORK DRIVER
L: netdev@vger.kernel.org
S: Orphan
--
2.17.1
^ permalink raw reply related [flat|nested] 18+ messages in thread