The patch titled
Subject: mm-smaps-split-pss-into-components-v5
has been added to the -mm tree. Its filename is
mm-smaps-split-pss-into-components-v5.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-smaps-split-pss-into-components-v5.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-smaps-split-pss-into-components-v5.patch
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------------------------------------------------------
From: Luigi Semenzato <semenzato@xxxxxxxxxxxx>
Subject: mm-smaps-split-pss-into-components-v5
Link: http://lkml.kernel.org/r/20190626234333.44608-1-semenzato@xxxxxxxxxxxx
Signed-off-by: Luigi Semenzato <semenzato@xxxxxxxxxxxx>
Acked-by: Yu Zhao <yuzhao@xxxxxxxxxxxx>
Cc: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxxxx>
Cc: Brian Geffon <bgeffon@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/procfs-smaps_rollup | 14 +++++-
Documentation/filesystems/proc.txt | 35 ++++++++++++----
2 files changed, 39 insertions(+), 10 deletions(-)
--- a/Documentation/ABI/testing/procfs-smaps_rollup~mm-smaps-split-pss-into-components-v5
+++ a/Documentation/ABI/testing/procfs-smaps_rollup
@@ -3,18 +3,28 @@ Date: August 2017
Contact: Daniel Colascione <dancol@xxxxxxxxxx>
Description:
This file provides pre-summed memory information for a
- process. The format is identical to /proc/pid/smaps,
+ process. The format is almost identical to /proc/pid/smaps,
except instead of an entry for each VMA in a process,
smaps_rollup has a single entry (tagged "[rollup]")
for which each field is the sum of the corresponding
fields from all the maps in /proc/pid/smaps.
- For more details, see the procfs man page.
+ Additionally, the fields Pss_Anon, Pss_File and Pss_Shmem
+ are not present in /proc/pid/smaps. These fields represent
+ the sum of the Pss field of each type (anon, file, shmem).
+ For more details, see Documentation/filesystems/proc.txt
+ and the procfs man page.
Typical output looks like this:
00100000-ff709000 ---p 00000000 00:00 0 [rollup]
+ Size: 1192 kB
+ KernelPageSize: 4 kB
+ MMUPageSize: 4 kB
Rss: 884 kB
Pss: 385 kB
+ Pss_Anon: 301 kB
+ Pss_File: 80 kB
+ Pss_Shmem: 4 kB
Shared_Clean: 696 kB
Shared_Dirty: 0 kB
Private_Clean: 120 kB
--- a/Documentation/filesystems/proc.txt~mm-smaps-split-pss-into-components-v5
+++ a/Documentation/filesystems/proc.txt
@@ -367,7 +367,7 @@ Table 1-4: Contents of the stat files (a
exit_code the thread's exit_code in the form reported by the waitpid system call
..............................................................................
-The /proc/PID/maps file containing the currently mapped memory regions and
+The /proc/PID/maps file contains the currently mapped memory regions and
their access permissions.
The format is:
@@ -418,11 +418,14 @@ is not associated with a file:
or if empty, the mapping is anonymous.
The /proc/PID/smaps is an extension based on maps, showing the memory
-consumption for each of the process's mappings. For each of mappings there
-is a series of lines such as the following:
+consumption for each of the process's mappings. For each mapping (aka Virtual
+Memory Area, or VMA) there is a series of lines such as the following:
08048000-080bc000 r-xp 00000000 03:02 13130 /bin/bash
+
Size: 1084 kB
+KernelPageSize: 4 kB
+MMUPageSize: 4 kB
Rss: 892 kB
Pss: 374 kB
Shared_Clean: 892 kB
@@ -444,11 +447,14 @@ Locked: 0 kB
THPeligible: 0
VmFlags: rd ex mr mw me dw
-the first of these lines shows the same information as is displayed for the
-mapping in /proc/PID/maps. The remaining lines show the size of the mapping
-(size), the amount of the mapping that is currently resident in RAM (RSS), the
-process' proportional share of this mapping (PSS), the number of clean and
-dirty private pages in the mapping.
+The first of these lines shows the same information as is displayed for the
+mapping in /proc/PID/maps. Following lines show the size of the mapping
+(size); the size of each page allocated when backing a VMA (KernelPageSize),
+which is usually the same as the size in the page table entries; the page size
+used by the MMU when backing a VMA (in most cases, the same as KernelPageSize);
+the amount of the mapping that is currently resident in RAM (RSS); the
+process' proportional share of this mapping (PSS); and the number of clean and
+dirty shared and private pages in the mapping.
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.
@@ -533,6 +539,19 @@ guarantees:
2) If there is something at a given vaddr during the entirety of the
life of the smaps/maps walk, there will be some output for it.
+The /proc/PID/smaps_rollup file includes the same fields as /proc/PID/smaps,
+but their values are the sums of the corresponding values for all mappings of
+the process. Additionally, it contains these fields:
+
+Pss_Anon
+Pss_File
+Pss_Shmem
+
+They represent the proportional shares of anonymous, file, and shmem pages, as
+described for smaps above. These fields are omitted in smaps since each
+mapping identifies the type (anon, file, or shmem) of all pages it contains.
+Thus all information in smaps_rollup can be derived from smaps, but at a
+significantly higher cost.
The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
bits on both physical and virtual pages associated with a process, and the
_
Patches currently in -mm which might be from semenzato@xxxxxxxxxxxx are
mm-smaps-split-pss-into-components.patch
mm-smaps-split-pss-into-components-v5.patch
