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author | Luigi Semenzato <semenzato@chromium.org> | 2019-07-12 06:00:10 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-12 20:05:47 +0200 |
commit | ee2ad71b0756e995fa4f6d922463e9bccd71b198 (patch) | |
tree | 0ca5415368b95cbe6890d915a98fc83c9e1eee3e /mm/vmalloc.c | |
parent | mm: use down_read_killable for locking mmap_sem in access_remote_vm (diff) | |
download | linux-ee2ad71b0756e995fa4f6d922463e9bccd71b198.tar.xz linux-ee2ad71b0756e995fa4f6d922463e9bccd71b198.zip |
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.
All the information is already present in /proc/pid/smaps, but much more
expensive to obtain because of the large size of that procfs entry.
This patch also removes a small code duplication in smaps_account, which
would have gotten worse otherwise.
Also updated Documentation/filesystems/proc.txt (the smaps section was a
bit stale, and I added a smaps_rollup section) and
Documentation/ABI/testing/procfs-smaps_rollup.
[semenzato@chromium.org: v5]
Link: http://lkml.kernel.org/r/20190626234333.44608-1-semenzato@chromium.org
Link: http://lkml.kernel.org/r/20190626180429.174569-1-semenzato@chromium.org
Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
Acked-by: Yu Zhao <yuzhao@chromium.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Yu Zhao <yuzhao@chromium.org>
Cc: Brian Geffon <bgeffon@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions