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| author | David Rientjes <rientjes@google.com> | 2010-08-09 17:19:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:45:02 -0700 |
| commit | 51b1bd2ace1595b72956224deda349efa880b693 (patch) | |
| tree | 82732bb33d26379c05494dcdba8ea390ae0621db /Documentation/feature-removal-schedule.txt | |
| parent | a63d83f427fbce97a6cea0db2e64b0eb8435cd10 (diff) | |
| download | lwn-51b1bd2ace1595b72956224deda349efa880b693.tar.gz lwn-51b1bd2ace1595b72956224deda349efa880b693.zip | |
oom: deprecate oom_adj tunable
/proc/pid/oom_adj is now deprecated so that that it may eventually be
removed. The target date for removal is August 2012.
A warning will be printed to the kernel log if a task attempts to use this
interface. Future warning will be suppressed until the kernel is rebooted
to prevent spamming the kernel log.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/feature-removal-schedule.txt')
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 71f0fea1058f..56cee4727b1a 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -151,6 +151,31 @@ Who: Eric Biederman <ebiederm@xmission.com> --------------------------- +What: /proc/<pid>/oom_adj +When: August 2012 +Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's + badness heuristic used to determine which task to kill when the kernel + is out of memory. + + The badness heuristic has since been rewritten since the introduction of + this tunable such that its meaning is deprecated. The value was + implemented as a bitshift on a score generated by the badness() + function that did not have any precise units of measure. With the + rewrite, the score is given as a proportion of available memory to the + task allocating pages, so using a bitshift which grows the score + exponentially is, thus, impossible to tune with fine granularity. + + A much more powerful interface, /proc/<pid>/oom_score_adj, was + introduced with the oom killer rewrite that allows users to increase or + decrease the badness() score linearly. This interface will replace + /proc/<pid>/oom_adj. + + A warning will be emitted to the kernel log if an application uses this + deprecated interface. After it is printed once, future warnings will be + suppressed until the kernel is rebooted. + +--------------------------- + What: remove EXPORT_SYMBOL(kernel_thread) When: August 2006 Files: arch/*/kernel/*_ksyms.c |