Cool! Andrew picked up the patch I liked.
Andres, how about adding it to olpc-2.6 too? Along with the
latest Memphis patch, it would give use us invaluable stats
for those trying to reduce memory usage.
-------- Original Message --------
Subject: + maps-pssproportional-set-size-accounting-in-smaps.patch added to -mm
tree
Date: Mon, 24 Sep 2007 13:32:10 -0700
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL
PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED],
[EMAIL PROTECTED]
The patch titled
maps: PSS(proportional set size) accounting in smaps
has been added to the -mm tree. Its filename is
maps-pssproportional-set-size-accounting-in-smaps.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: maps: PSS(proportional set size) accounting in smaps
From: Fengguang Wu <[EMAIL PROTECTED]>
The "proportional set size" (PSS) of a process is the count of pages it has
in memory, where each page is divided by the number of processes sharing
it. So if a process has 1000 pages all to itself, and 1000 shared with one
other process, its PSS will be 1500.
- lwn.net: "ELC: How much memory are applications really using?"
The PSS proposed by Matt Mackall is a very nice metic for measuring an
process's memory footprint. So collect and export it via
/proc/<pid>/smaps.
Matt Mackall's pagemap/kpagemap and John Berthels's exmap can also do the
job. They are comprehensive tools. But for PSS, let's do it in the simple
way.
Cc: John Berthels <[EMAIL PROTECTED]>
Cc: Bernardo Innocenti <[EMAIL PROTECTED]>
Cc: Padraig Brady <[EMAIL PROTECTED]>
Cc: Denys Vlasenko <[EMAIL PROTECTED]>
Cc: Balbir Singh <[EMAIL PROTECTED]>
Acked-by: Matt Mackall <[EMAIL PROTECTED]>
Signed-off-by: Fengguang Wu <[EMAIL PROTECTED]>
Cc: Hugh Dickins <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
fs/proc/task_mmu.c | 29 ++++++++++++++++++++++++++++-
1 files changed, 28 insertions(+), 1 deletion(-)
diff -puN fs/proc/task_mmu.c~maps-pssproportional-set-size-accounting-in-smaps
fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~maps-pssproportional-set-size-accounting-in-smaps
+++ a/fs/proc/task_mmu.c
@@ -324,6 +324,27 @@ struct mem_size_stats
unsigned long private_clean;
unsigned long private_dirty;
unsigned long referenced;
+
+ /*
+ * Proportional Set Size(PSS): my share of RSS.
+ *
+ * PSS of a process is the count of pages it has in memory, where each
+ * page is divided by the number of processes sharing it. So if a
+ * process has 1000 pages all to itself, and 1000 shared with one other
+ * process, its PSS will be 1500. - Matt Mackall, lwn.net
+ */
+ u64 pss;
+ /*
+ * To keep (accumulated) division errors low, we adopt 64bit pss and
+ * use some low bits for division errors. So (pss >> PSS_DIV_BITS)
+ * would be the real byte count.
+ *
+ * A shift of 12 before division means(assuming 4K page size):
+ * - 1M 3-user-pages add up to 8KB errors;
+ * - supports mapcount up to 2^24, or 16M;
+ * - supports PSS up to 2^52 bytes, or 4PB.
+ */
+#define PSS_DIV_BITS 12
};
struct smaps_arg
@@ -341,6 +362,7 @@ static int smaps_pte_range(pmd_t *pmd, u
pte_t *pte, ptent;
spinlock_t *ptl;
struct page *page;
+ int mapcount;
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
for (; addr != end; pte++, addr += PAGE_SIZE) {
@@ -357,16 +379,19 @@ static int smaps_pte_range(pmd_t *pmd, u
/* Accumulate the size in pages that have been accessed. */
if (pte_young(ptent) || PageReferenced(page))
mss->referenced += PAGE_SIZE;
- if (page_mapcount(page) >= 2) {
+ mapcount = page_mapcount(page);
+ if (mapcount >= 2) {
if (pte_dirty(ptent))
mss->shared_dirty += PAGE_SIZE;
else
mss->shared_clean += PAGE_SIZE;
+ mss->pss += (PAGE_SIZE << PSS_DIV_BITS) / mapcount;
} else {
if (pte_dirty(ptent))
mss->private_dirty += PAGE_SIZE;
else
mss->private_clean += PAGE_SIZE;
+ mss->pss += (PAGE_SIZE << PSS_DIV_BITS);
}
}
pte_unmap_unlock(pte - 1, ptl);
@@ -395,6 +420,7 @@ static int show_smap(struct seq_file *m,
seq_printf(m,
"Size: %8lu kB\n"
"Rss: %8lu kB\n"
+ "Pss: %8lu kB\n"
"Shared_Clean: %8lu kB\n"
"Shared_Dirty: %8lu kB\n"
"Private_Clean: %8lu kB\n"
@@ -402,6 +428,7 @@ static int show_smap(struct seq_file *m,
"Referenced: %8lu kB\n",
(vma->vm_end - vma->vm_start) >> 10,
sarg.mss.resident >> 10,
+ (unsigned long)(sarg.mss.pss >> (10 + PSS_DIV_BITS)),
sarg.mss.shared_clean >> 10,
sarg.mss.shared_dirty >> 10,
sarg.mss.private_clean >> 10,
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
readahead-compacting-file_ra_state.patch
readahead-mmap-read-around-simplification.patch
readahead-combine-file_ra_stateprev_index-prev_offset-into-prev_pos.patch
readahead-combine-file_ra_stateprev_index-prev_offset-into-prev_pos-fix.patch
readahead-combine-file_ra_stateprev_index-prev_offset-into-prev_pos-fix-2.patch
radixtree-introduce-radix_tree_next_hole.patch
readahead-basic-support-of-interleaved-reads.patch
readahead-remove-the-local-copy-of-ra-in-do_generic_mapping_read.patch
readahead-remove-several-readahead-macros.patch
readahead-remove-the-limit-max_sectors_kb-imposed-on-max_readahead_kb.patch
filemap-trivial-code-cleanups.patch
filemap-convert-some-unsigned-long-to-pgoff_t.patch
make-swappiness-safer-to-use.patch
maps-pssproportional-set-size-accounting-in-smaps.patch
convert-ill-defined-log2-to-ilog2.patch
seqfile-merge-duplite-code-to-seq_open_private.patch
avoid-negative-and-full-width-shifts-in-radix-treec.patch
--
\___/
|___| Bernardo Innocenti - http://www.codewiz.org/
\___\ One Laptop Per Child - http://www.laptop.org/
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