* [PATCH 1/1] mm: smaps: split PSS into components
@ 2019-06-26 18:04 semenzato
2019-06-26 22:19 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: semenzato @ 2019-06-26 18:04 UTC (permalink / raw)
To: linux-mm, akpm; +Cc: yuzhao, bgeffon, sonnyrao, Luigi Semenzato
From: Luigi Semenzato <semenzato@chromium.org>
Report separate components (anon, file, and shmem)
for PSS in smaps_rollup.
This helps understand and tune the memory manager behavior
in consumer devices, particularly mobile devices. Many of
them (e.g. chromebooks and Android-based devices) use zram
for anon memory, and perform disk reads for discarded file
pages. The difference in latency is large (e.g. reading
a single page from SSD is 30 times slower than decompressing
a zram page on one popular device), thus it is useful to know
how much of the PSS is anon vs. file.
This patch also removes a small code duplication in smaps_account,
which would have gotten worse otherwise.
Also added missing entry for smaps_rollup in
Documentation/filesystems/proc.txt.
Acked-by: Yu Zhao <yuzhao@chromium.org>
Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
---
Documentation/filesystems/proc.txt | 6 +-
fs/proc/task_mmu.c | 92 ++++++++++++++++++++----------
2 files changed, 66 insertions(+), 32 deletions(-)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 66cad5c86171..b48e85e19877 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -153,9 +153,11 @@ Table 1-1: Process specific entries in /proc
symbol the task is blocked in - or "0" if not blocked.
pagemap Page table
stack Report full stack trace, enable via CONFIG_STACKTRACE
- smaps an extension based on maps, showing the memory consumption of
+ smaps An extension based on maps, showing the memory consumption of
each mapping and flags associated with it
- numa_maps an extension based on maps, showing the memory locality and
+ smaps_rollup Accumulated smaps stats for all mappings of the process. This
+ can be derived from smaps, but is faster and more convenient
+ numa_maps An extension based on maps, showing the memory locality and
binding policy as well as mem usage (in pages) of each mapping.
..............................................................................
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 01d4eb0e6bd1..00d110dcd6c2 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -417,17 +417,53 @@ struct mem_size_stats {
unsigned long shared_hugetlb;
unsigned long private_hugetlb;
u64 pss;
+ u64 pss_anon;
+ u64 pss_file;
+ u64 pss_shmem;
u64 pss_locked;
u64 swap_pss;
bool check_shmem_swap;
};
+static void smaps_page_accumulate(struct mem_size_stats *mss,
+ struct page *page, unsigned long size, unsigned long pss,
+ bool dirty, bool locked, bool private)
+{
+ mss->pss += pss;
+
+ if (PageAnon(page))
+ mss->pss_anon += pss;
+ else if (PageSwapBacked(page))
+ mss->pss_shmem += pss;
+ else
+ mss->pss_file += pss;
+
+ if (locked)
+ mss->pss_locked += pss;
+
+ if (dirty || PageDirty(page)) {
+ if (private)
+ mss->private_dirty += size;
+ else
+ mss->shared_dirty += size;
+ } else {
+ if (private)
+ mss->private_clean += size;
+ else
+ mss->shared_clean += size;
+ }
+}
+
static void smaps_account(struct mem_size_stats *mss, struct page *page,
bool compound, bool young, bool dirty, bool locked)
{
int i, nr = compound ? 1 << compound_order(page) : 1;
unsigned long size = nr * PAGE_SIZE;
+ /*
+ * First accumulate quantities that depend only on |size| and the type
+ * of the compound page.
+ */
if (PageAnon(page)) {
mss->anonymous += size;
if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
@@ -440,42 +476,25 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
mss->referenced += size;
/*
+ * Then accumulate quantities that may depend on sharing, or that may
+ * differ page-by-page.
+ *
* page_count(page) == 1 guarantees the page is mapped exactly once.
* If any subpage of the compound page mapped with PTE it would elevate
* page_count().
*/
if (page_count(page) == 1) {
- if (dirty || PageDirty(page))
- mss->private_dirty += size;
- else
- mss->private_clean += size;
- mss->pss += (u64)size << PSS_SHIFT;
- if (locked)
- mss->pss_locked += (u64)size << PSS_SHIFT;
+ smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
+ locked, true);
return;
}
-
for (i = 0; i < nr; i++, page++) {
int mapcount = page_mapcount(page);
- unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
-
- if (mapcount >= 2) {
- if (dirty || PageDirty(page))
- mss->shared_dirty += PAGE_SIZE;
- else
- mss->shared_clean += PAGE_SIZE;
- mss->pss += pss / mapcount;
- if (locked)
- mss->pss_locked += pss / mapcount;
- } else {
- if (dirty || PageDirty(page))
- mss->private_dirty += PAGE_SIZE;
- else
- mss->private_clean += PAGE_SIZE;
- mss->pss += pss;
- if (locked)
- mss->pss_locked += pss;
- }
+ unsigned long pss = PAGE_SIZE << PSS_SHIFT;
+ if (mapcount >= 2)
+ pss /= mapcount;
+ smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked,
+ mapcount < 2);
}
}
@@ -754,10 +773,23 @@ static void smap_gather_stats(struct vm_area_struct *vma,
seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
/* Show the contents common for smaps and smaps_rollup */
-static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss)
+static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
+ bool rollup_mode)
{
SEQ_PUT_DEC("Rss: ", mss->resident);
SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
+ if (rollup_mode) {
+ /*
+ * These are meaningful only for smaps_rollup, otherwise two of
+ * them are zero, and the other one is the same as Pss.
+ */
+ SEQ_PUT_DEC(" kB\nPss_Anon: ",
+ mss->pss_anon >> PSS_SHIFT);
+ SEQ_PUT_DEC(" kB\nPss_File: ",
+ mss->pss_file >> PSS_SHIFT);
+ SEQ_PUT_DEC(" kB\nPss_Shmem: ",
+ mss->pss_shmem >> PSS_SHIFT);
+ }
SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean);
SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty);
SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean);
@@ -794,7 +826,7 @@ static int show_smap(struct seq_file *m, void *v)
SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma));
seq_puts(m, " kB\n");
- __show_smap(m, &mss);
+ __show_smap(m, &mss, false);
seq_printf(m, "THPeligible: %d\n", transparent_hugepage_enabled(vma));
@@ -841,7 +873,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
seq_pad(m, ' ');
seq_puts(m, "[rollup]\n");
- __show_smap(m, &mss);
+ __show_smap(m, &mss, true);
release_task_mempolicy(priv);
up_read(&mm->mmap_sem);
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] mm: smaps: split PSS into components
2019-06-26 18:04 [PATCH 1/1] mm: smaps: split PSS into components semenzato
@ 2019-06-26 22:19 ` Andrew Morton
2019-06-26 23:40 ` Luigi Semenzato
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2019-06-26 22:19 UTC (permalink / raw)
To: semenzato; +Cc: linux-mm, yuzhao, bgeffon, sonnyrao
On Wed, 26 Jun 2019 11:04:29 -0700 semenzato@chromium.org wrote:
> From: Luigi Semenzato <semenzato@chromium.org>
>
> Report separate components (anon, file, and shmem)
> for PSS in smaps_rollup.
>
> This helps understand and tune the memory manager behavior
> in consumer devices, particularly mobile devices. Many of
> them (e.g. chromebooks and Android-based devices) use zram
> for anon memory, and perform disk reads for discarded file
> pages. The difference in latency is large (e.g. reading
> a single page from SSD is 30 times slower than decompressing
> a zram page on one popular device), thus it is useful to know
> how much of the PSS is anon vs. file.
>
> This patch also removes a small code duplication in smaps_account,
> which would have gotten worse otherwise.
>
> Also added missing entry for smaps_rollup in
> Documentation/filesystems/proc.txt.
>
> ...
>
> -static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss)
> +static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
> + bool rollup_mode)
> {
> SEQ_PUT_DEC("Rss: ", mss->resident);
> SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
> + if (rollup_mode) {
> + /*
> + * These are meaningful only for smaps_rollup, otherwise two of
> + * them are zero, and the other one is the same as Pss.
> + */
> + SEQ_PUT_DEC(" kB\nPss_Anon: ",
> + mss->pss_anon >> PSS_SHIFT);
> + SEQ_PUT_DEC(" kB\nPss_File: ",
> + mss->pss_file >> PSS_SHIFT);
> + SEQ_PUT_DEC(" kB\nPss_Shmem: ",
> + mss->pss_shmem >> PSS_SHIFT);
> + }
Documentation/filesystems/proc.txt is rather incomplete. It documents
/proc/PID/smaps (seems to be out of date) but doesn't describe the
fields in smaps_rollup.
Please update Documentation/ABI/testing/procfs-smaps_rollup and please
check that it's up-to-date while you're in there.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] mm: smaps: split PSS into components
2019-06-26 22:19 ` Andrew Morton
@ 2019-06-26 23:40 ` Luigi Semenzato
0 siblings, 0 replies; 4+ messages in thread
From: Luigi Semenzato @ 2019-06-26 23:40 UTC (permalink / raw)
To: Andrew Morton; +Cc: Linux Memory Management List, Yu Zhao, bgeffon, Sonny Rao
On Wed, Jun 26, 2019 at 3:19 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Wed, 26 Jun 2019 11:04:29 -0700 semenzato@chromium.org wrote:
>
> > From: Luigi Semenzato <semenzato@chromium.org>
> >
> > Report separate components (anon, file, and shmem)
> > for PSS in smaps_rollup.
> >
> > This helps understand and tune the memory manager behavior
> > in consumer devices, particularly mobile devices. Many of
> > them (e.g. chromebooks and Android-based devices) use zram
> > for anon memory, and perform disk reads for discarded file
> > pages. The difference in latency is large (e.g. reading
> > a single page from SSD is 30 times slower than decompressing
> > a zram page on one popular device), thus it is useful to know
> > how much of the PSS is anon vs. file.
> >
> > This patch also removes a small code duplication in smaps_account,
> > which would have gotten worse otherwise.
> >
> > Also added missing entry for smaps_rollup in
> > Documentation/filesystems/proc.txt.
> >
> > ...
> >
> > -static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss)
> > +static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
> > + bool rollup_mode)
> > {
> > SEQ_PUT_DEC("Rss: ", mss->resident);
> > SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
> > + if (rollup_mode) {
> > + /*
> > + * These are meaningful only for smaps_rollup, otherwise two of
> > + * them are zero, and the other one is the same as Pss.
> > + */
> > + SEQ_PUT_DEC(" kB\nPss_Anon: ",
> > + mss->pss_anon >> PSS_SHIFT);
> > + SEQ_PUT_DEC(" kB\nPss_File: ",
> > + mss->pss_file >> PSS_SHIFT);
> > + SEQ_PUT_DEC(" kB\nPss_Shmem: ",
> > + mss->pss_shmem >> PSS_SHIFT);
> > + }
>
> Documentation/filesystems/proc.txt is rather incomplete. It documents
> /proc/PID/smaps (seems to be out of date) but doesn't describe the
> fields in smaps_rollup.
>
> Please update Documentation/ABI/testing/procfs-smaps_rollup and please
> check that it's up-to-date while you're in there.
>
Thank you for noticing the stale/missing docs and sorry that I did not.
Will email the updated patch shortly.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/1] mm: smaps: split PSS into components
@ 2019-05-22 23:53 semenzato
0 siblings, 0 replies; 4+ messages in thread
From: semenzato @ 2019-05-22 23:53 UTC (permalink / raw)
To: linux-mm; +Cc: minchan, sonnyrao, dtor, Luigi Semenzato
From: Luigi Semenzato <semenzato@chromium.org>
Report separate components (anon, file, and shmem)
for PSS in smaps and smaps_rollup.
This helps understand and tune the memory manager behavior
in consumer devices, particularly mobile devices. Many of
them (e.g. chromebooks and Android-based devices) use zram
for anon memory, and perform disk reads for discarded file
pages. The difference in latency is large (e.g. reading
a single page from SSD is 30 times slower than decompressing
a zram page on one popular device), thus it is useful to know
how much of the PSS is anon vs. file.
This patch also removes a small code duplication in smaps_account,
which would have gotten worse otherwise.
Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
---
fs/proc/task_mmu.c | 61 ++++++++++++++++++++++++++++------------------
1 file changed, 37 insertions(+), 24 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 01d4eb0e6bd1..4b586c4d27b0 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -417,17 +417,45 @@ struct mem_size_stats {
unsigned long shared_hugetlb;
unsigned long private_hugetlb;
u64 pss;
+ u64 pss_anon;
+ u64 pss_file;
+ u64 pss_shmem;
u64 pss_locked;
u64 swap_pss;
bool check_shmem_swap;
};
+static void smaps_page_accumulate(struct mem_size_stats *mss,
+ struct page *page, unsigned long size, unsigned long pss,
+ bool dirty, bool locked)
+{
+ mss->pss += pss;
+
+ if (PageAnon(page))
+ mss->pss_anon += pss;
+ else if (PageSwapBacked(page))
+ mss->pss_shmem += pss;
+ else
+ mss->pss_file += pss;
+
+ if (locked)
+ mss->pss_locked += pss;
+ if (dirty || PageDirty(page))
+ mss->shared_dirty += size;
+ else
+ mss->shared_clean += size;
+}
+
static void smaps_account(struct mem_size_stats *mss, struct page *page,
bool compound, bool young, bool dirty, bool locked)
{
int i, nr = compound ? 1 << compound_order(page) : 1;
unsigned long size = nr * PAGE_SIZE;
+ /*
+ * First accumulate quantities that depend only on |size| and the type
+ * of the compound page.
+ */
if (PageAnon(page)) {
mss->anonymous += size;
if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
@@ -440,42 +468,24 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
mss->referenced += size;
/*
+ * Then accumulate quantities that may depend on sharing, or that may
+ * differ page-by-page.
+ *
* page_count(page) == 1 guarantees the page is mapped exactly once.
* If any subpage of the compound page mapped with PTE it would elevate
* page_count().
*/
if (page_count(page) == 1) {
- if (dirty || PageDirty(page))
- mss->private_dirty += size;
- else
- mss->private_clean += size;
- mss->pss += (u64)size << PSS_SHIFT;
- if (locked)
- mss->pss_locked += (u64)size << PSS_SHIFT;
+ smaps_page_accumulate(mss, page, size, size, dirty, locked);
return;
}
-
for (i = 0; i < nr; i++, page++) {
int mapcount = page_mapcount(page);
unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
-
if (mapcount >= 2) {
- if (dirty || PageDirty(page))
- mss->shared_dirty += PAGE_SIZE;
- else
- mss->shared_clean += PAGE_SIZE;
- mss->pss += pss / mapcount;
- if (locked)
- mss->pss_locked += pss / mapcount;
- } else {
- if (dirty || PageDirty(page))
- mss->private_dirty += PAGE_SIZE;
- else
- mss->private_clean += PAGE_SIZE;
- mss->pss += pss;
- if (locked)
- mss->pss_locked += pss;
+ pss /= mapcount;
}
+ smaps_page_accumulate(mss, page, PAGE_SIZE, pss, dirty, locked);
}
}
@@ -758,6 +768,9 @@ static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss)
{
SEQ_PUT_DEC("Rss: ", mss->resident);
SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
+ SEQ_PUT_DEC(" kB\nPss_Anon: ", mss->pss_anon >> PSS_SHIFT);
+ SEQ_PUT_DEC(" kB\nPss_File: ", mss->pss_file >> PSS_SHIFT);
+ SEQ_PUT_DEC(" kB\nPss_Shmem: ", mss->pss_shmem >> PSS_SHIFT);
SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean);
SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty);
SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean);
--
2.21.0.1020.gf2820cf01a-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
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2019-06-26 18:04 [PATCH 1/1] mm: smaps: split PSS into components semenzato
2019-06-26 22:19 ` Andrew Morton
2019-06-26 23:40 ` Luigi Semenzato
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2019-05-22 23:53 semenzato
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