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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2010-03-05 22:41:42 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-06 20:26:24 +0100
commitb084d4353ff99d824d3bc5a5c2c22c70b1fba722 (patch)
tree8178db2b337fc8a36e6ca2e1fc2e7d7473957e27 /Documentation/filesystems/proc.txt
parentmm: avoid false sharing of mm_counter (diff)
downloadlinux-b084d4353ff99d824d3bc5a5c2c22c70b1fba722.tar.xz
linux-b084d4353ff99d824d3bc5a5c2c22c70b1fba722.zip
mm: count swap usage
A frequent questions from users about memory management is what numbers of swap ents are user for processes. And this information will give some hints to oom-killer. Besides we can count the number of swapents per a process by scanning /proc/<pid>/smaps, this is very slow and not good for usual process information handler which works like 'ps' or 'top'. (ps or top is now enough slow..) This patch adds a counter of swapents to mm_counter and update is at each swap events. Information is exported via /proc/<pid>/status file as [kamezawa@bluextal memory]$ cat /proc/self/status Name: cat State: R (running) Tgid: 2910 Pid: 2910 PPid: 2823 TracerPid: 0 Uid: 500 500 500 500 Gid: 500 500 500 500 FDSize: 256 Groups: 500 VmPeak: 82696 kB VmSize: 82696 kB VmLck: 0 kB VmHWM: 432 kB VmRSS: 432 kB VmData: 172 kB VmStk: 84 kB VmExe: 48 kB VmLib: 1568 kB VmPTE: 40 kB VmSwap: 0 kB <=============== this. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems/proc.txt')
-rw-r--r--Documentation/filesystems/proc.txt2
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index e418f3d8f427..b5c5fc657a88 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -164,6 +164,7 @@ read the file /proc/PID/status:
VmExe: 68 kB
VmLib: 1412 kB
VmPTE: 20 kb
+ VmSwap: 0 kB
Threads: 1
SigQ: 0/28578
SigPnd: 0000000000000000
@@ -219,6 +220,7 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7)
VmExe size of text segment
VmLib size of shared library code
VmPTE size of page table entries
+ VmSwap size of swap usage (the number of referred swapents)
Threads number of threads
SigQ number of signals queued/max. number for queue
SigPnd bitmap of pending signals for the thread