The patch titled
Subject: mm: smaps: split PSS into components
has been added to the -mm tree. Its filename is
mm-smaps-split-pss-into-components.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-smaps-split-pss-into-components.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-smaps-split-pss-into-components.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Luigi Semenzato <semenzato@xxxxxxxxxxxx>
Subject: mm: smaps: split PSS into components
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.
Link: http://lkml.kernel.org/r/20190531154645.39365-1-semenzato@xxxxxxxxxxxx
Signed-off-by: Luigi Semenzato <semenzato@xxxxxxxxxxxx>
Acked-by: Yu Zhao <yuzhao@xxxxxxxxxxxx>
Cc: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Dmitry Torokhov <dtor@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 6 +
fs/proc/task_mmu.c | 89 ++++++++++++++++++---------
2 files changed, 64 insertions(+), 31 deletions(-)
--- a/Documentation/filesystems/proc.txt~mm-smaps-split-pss-into-components
+++ a/Documentation/filesystems/proc.txt
@@ -153,9 +153,11 @@ Table 1-1: Process specific entries in /
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.
..............................................................................
--- a/fs/proc/task_mmu.c~mm-smaps-split-pss-into-components
+++ a/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 +476,24 @@ static void smaps_account(struct mem_siz
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);
+ 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;
- }
+ smaps_page_accumulate(mss, page, PAGE_SIZE, pss / mapcount,
+ dirty, locked, mapcount < 2);
}
}
@@ -754,10 +772,23 @@ static void smap_gather_stats(struct vm_
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 +825,7 @@ static int show_smap(struct seq_file *m,
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 +872,7 @@ static int show_smaps_rollup(struct seq_
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);
_
Patches currently in -mm which might be from semenzato@xxxxxxxxxxxx are
mm-smaps-split-pss-into-components.patch
