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From: <sjpark@amazon.com>
To: <akpm@linux-foundation.org>
Cc: SeongJae Park <sjpark@amazon.de>, <acme@kernel.org>,
	<alexander.shishkin@linux.intel.com>, <amit@kernel.org>,
	<brendan.d.gregg@gmail.com>, <brendanhiggins@google.com>,
	<cai@lca.pw>, <colin.king@canonical.com>, <corbet@lwn.net>,
	<dwmw@amazon.com>, <jolsa@redhat.com>, <kirill@shutemov.name>,
	<mark.rutland@arm.com>, <mgorman@suse.de>, <minchan@kernel.org>,
	<mingo@redhat.com>, <namhyung@kernel.org>, <peterz@infradead.org>,
	<rdunlap@infradead.org>, <rostedt@goodmis.org>,
	<sj38.park@gmail.com>, <vdavydov.dev@gmail.com>,
	<linux-mm@kvack.org>, <linux-doc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH v4 05/11] mm/damon: Implement kernel space API
Date: Mon, 10 Feb 2020 15:50:43 +0100
Message-ID: <20200210145043.27684-1-sjpark@amazon.com> (raw)
In-Reply-To: <20200210144812.26845-1-sjpark@amazon.com>

From: SeongJae Park <sjpark@amazon.de>

This commit implements the DAMON api for the kernel.  Other kernel code
can use DAMON by calling damon_start() and damon_stop() with their own
'struct damon_ctx'.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
 include/linux/damon.h | 71 +++++++++++++++++++++++++++++++++++++++++++
 mm/damon.c            | 70 +++++++++++-------------------------------
 2 files changed, 89 insertions(+), 52 deletions(-)
 create mode 100644 include/linux/damon.h

diff --git a/include/linux/damon.h b/include/linux/damon.h
new file mode 100644
index 000000000000..78785cb88d42
--- /dev/null
+++ b/include/linux/damon.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DAMON api
+ *
+ * Copyright 2019 Amazon.com, Inc. or its affiliates.  All rights reserved.
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#ifndef _DAMON_H_
+#define _DAMON_H_
+
+#include <linux/random.h>
+#include <linux/spinlock_types.h>
+#include <linux/time64.h>
+#include <linux/types.h>
+
+/* Represents a monitoring target region on the virtual address space */
+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 {
+	unsigned long pid;
+	struct list_head regions_list;
+	struct list_head list;
+};
+
+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;
+
+	unsigned char *rbuf;
+	unsigned int rbuf_len;
+	unsigned int rbuf_offset;
+	char *rfile_path;
+
+	struct task_struct *kdamond;
+	bool kdamond_stop;
+	spinlock_t kdamond_lock;
+
+	struct rnd_state rndseed;
+
+	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,
+			unsigned long *pids, ssize_t nr_pids);
+int damon_set_recording(struct damon_ctx *ctx,
+			unsigned int rbuf_len, char *rfile_path);
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long s, unsigned long a,
+			unsigned long r, unsigned long min, unsigned long max);
+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 c2c40e003580..450b85bef120 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt) "damon: " fmt
 
+#include <linux/damon.h>
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/mm.h>
@@ -40,55 +41,6 @@
 #define damon_for_each_task_safe(ctx, t, next) \
 	list_for_each_entry_safe(t, next, &(ctx)->tasks_list, list)
 
-/* Represents a monitoring target region on the virtual address space */
-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 {
-	unsigned long pid;
-	struct list_head regions_list;
-	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 'aggr_interval' and then flushes it to the result buffer if
- * an 'aggr_interval' surpassed.  And for each 'regions_update_interval', damon
- * checks whether the memory mapping of the target tasks has changed (e.g., by
- * mmap() calls from the applications) and applies the changes.
- *
- * 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;
-
-	unsigned char *rbuf;
-	unsigned int rbuf_len;
-	unsigned int rbuf_offset;
-	char *rfile_path;
-
-	struct task_struct *kdamond;
-	bool kdamond_stop;
-	spinlock_t kdamond_lock;
-
-	struct rnd_state rndseed;
-
-	struct list_head tasks_list;	/* 'damon_task' objects */
-};
-
 #define LEN_RES_FILE_PATH	256
 
 /* Get a random number in [l, r) */
@@ -885,11 +837,15 @@ static int kdamond_fn(void *data)
 			}
 			mmput(mm);
 		}
+		if (ctx->sample_cb)
+			ctx->sample_cb(ctx);
 
 		if (kdamond_aggregate_interval_passed(ctx)) {
 			kdamond_merge_regions(ctx, max_nr_accesses / 10);
 			kdamond_flush_aggregated(ctx);
 			kdamond_split_regions(ctx);
+			if (ctx->aggregate_cb)
+				ctx->aggregate_cb(ctx);
 		}
 
 		if (kdamond_need_update_regions(ctx))
@@ -952,6 +908,16 @@ static int damon_turn_kdamond(struct damon_ctx *ctx, bool on)
 	return 0;
 }
 
+int damon_start(struct damon_ctx *ctx)
+{
+	return damon_turn_kdamond(ctx, true);
+}
+
+int damon_stop(struct damon_ctx *ctx)
+{
+	return damon_turn_kdamond(ctx, false);
+}
+
 static inline bool damon_is_target_pid(struct damon_ctx *c, unsigned long pid)
 {
 	struct damon_task *t;
@@ -966,7 +932,7 @@ static inline bool damon_is_target_pid(struct damon_ctx *c, unsigned long pid)
 /*
  * This function should not be called while the kdamond is running.
  */
-static int damon_set_pids(struct damon_ctx *ctx,
+int damon_set_pids(struct damon_ctx *ctx,
 			unsigned long *pids, ssize_t nr_pids)
 {
 	ssize_t i;
@@ -1007,7 +973,7 @@ static int damon_set_pids(struct damon_ctx *ctx,
  *
  * Returns 0 on success, negative error code otherwise.
  */
-static int damon_set_recording(struct damon_ctx *ctx,
+int damon_set_recording(struct damon_ctx *ctx,
 				unsigned int rbuf_len, char *path_to_rfile)
 {
 	size_t rfile_path_len;
@@ -1051,7 +1017,7 @@ static int damon_set_recording(struct damon_ctx *ctx,
  *
  * Returns 0 on success, negative error code otherwise.
  */
-static int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_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)
 {
-- 
2.17.1



  parent reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 14:48 [PATCH v4 00/11] Introduce Data Access MONitor (DAMON) sjpark
2020-02-10 14:48 ` [PATCH v4 01/11] mm: " sjpark
2020-02-10 14:48 ` [PATCH v4 02/11] mm/damon: Implement region based sampling sjpark
2020-02-10 14:48 ` [PATCH v4 03/11] mm/damon: Adaptively adjust regions sjpark
2020-02-10 14:48 ` [PATCH v4 04/11] mm/damon: Apply dynamic memory mapping changes sjpark
2020-02-10 14:50 ` sjpark [this message]
2020-02-12 23:21   ` [PATCH v4 05/11] mm/damon: Implement kernel space API kbuild test robot
2020-02-13  9:09     ` SeongJae Park
2020-02-10 14:51 ` [PATCH v4 06/11] mm/damon: Add debugfs interface sjpark
2020-02-10 14:52 ` [PATCH v4 07/11] mm/damon: Add a tracepoint for result writing sjpark
2020-02-10 14:52 ` [PATCH v4 08/11] tools: Add a minimal user-space tool for DAMON sjpark
2020-02-10 14:53 ` [PATCH v4 09/11] Documentation/admin-guide/mm: Add a document " sjpark
2020-02-10 14:53 ` [PATCH v4 10/11] mm/damon: Add kunit tests sjpark
2020-02-11 22:21   ` Brendan Higgins
2020-02-13 16:56   ` kbuild test robot
2020-02-14 11:19     ` SeongJae Park
2020-02-15  4:07   ` Randy Dunlap
2020-02-15  6:52     ` SeongJae Park
2020-02-10 14:54 ` [PATCH v4 11/11] MAINTAINERS: Update for DAMON sjpark

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