diff options
| author | David Rientjes <rientjes@google.com> | 2018-04-06 02:25:19 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-06 07:36:27 +0300 |
| commit | d46078b2888947a86b6bb997cd5927e602e8fdc9 (patch) | |
| tree | 84c5dedfbf534274212214e7f3c31af8a69547e7 | |
| parent | 5ecd9d403ad081ed2de7b118c1e96124d4e0ba6c (diff) | |
| download | linux-d46078b2888947a86b6bb997cd5927e602e8fdc9.tar.xz | |
mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes
Since the 2.6 kernel, the oom killer has slightly biased away from
CAP_SYS_ADMIN processes by discounting some of its memory usage in
comparison to other processes.
This has always been implicit and nothing exactly relies on the
behavior.
Gaurav notices that __task_cred() can dereference a potentially freed
pointer if the task under consideration is exiting because a reference
to the task_struct is not held.
Remove the CAP_SYS_ADMIN bias so that all processes are treated equally.
If any CAP_SYS_ADMIN process would like to be biased against, it is
always allowed to adjust /proc/pid/oom_score_adj.
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803071548510.6996@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Gaurav Kohli <gkohli@codeaurora.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/oom_kill.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 82a92ad67af3..c4c9ecd17c6e 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -226,13 +226,6 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, mm_pgtables_bytes(p->mm) / PAGE_SIZE; task_unlock(p); - /* - * Root processes get 3% bonus, just like the __vm_enough_memory() - * implementation used by LSMs. - */ - if (has_capability_noaudit(p, CAP_SYS_ADMIN)) - points -= (points * 3) / 100; - /* Normalize to oom_score_adj units */ adj *= totalpages / 1000; points += adj; |