diff options
| author | Mandeep Singh Baines <[email protected]> | 2011-01-13 23:46:05 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2011-01-14 01:32:35 +0000 |
| commit | dabb16f639820267b3850d804571c70bd93d4e07 (patch) | |
| tree | 7da59e6133cd2f820389574ac9206c56e046f5d4 /Documentation/filesystems | |
| parent | mm: unify module_alloc code for vmalloc (diff) | |
| download | kernel-dabb16f639820267b3850d804571c70bd93d4e07.tar.gz kernel-dabb16f639820267b3850d804571c70bd93d4e07.zip | |
oom: allow a non-CAP_SYS_RESOURCE proces to oom_score_adj down
We'd like to be able to oom_score_adj a process up/down as it
enters/leaves the foreground. Currently, it is not possible to oom_adj
down without CAP_SYS_RESOURCE. This patch allows a task to decrease its
oom_score_adj back to the value that a CAP_SYS_RESOURCE thread set it to
or its inherited value at fork. Assuming the thread that has forked it
has oom_score_adj of 0, each process could decrease it back from 0 upon
activation unless a CAP_SYS_RESOURCE thread elevated it to something
higher.
Alternative considered:
* a setuid binary
* a daemon with CAP_SYS_RESOURCE
Since you don't wan't all processes to be able to reduce their oom_adj, a
setuid or daemon implementation would be complex. The alternatives also
have much higher overhead.
This patch updated from original patch based on feedback from David
Rientjes.
Signed-off-by: Mandeep Singh Baines <[email protected]>
Acked-by: David Rientjes <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Ying Han <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index ef757fca470b..23cae6548d3a 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1323,6 +1323,10 @@ scaled linearly with /proc/<pid>/oom_score_adj. Writing to /proc/<pid>/oom_score_adj or /proc/<pid>/oom_adj will change the other with its scaled value. +The value of /proc/<pid>/oom_score_adj may be reduced no lower than the last +value set by a CAP_SYS_RESOURCE process. To reduce the value any lower +requires CAP_SYS_RESOURCE. + NOTICE: /proc/<pid>/oom_adj is deprecated and will be removed, please see Documentation/feature-removal-schedule.txt. |