diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-01-21 15:50:00 -0800 |
|---|---|---|
| committer | Mandar Padmawar <mpadmawar@nvidia.com> | 2014-06-18 21:33:21 -0700 |
| commit | 84ce23d27df5d272da0226d6ca4a40cffa348621 (patch) | |
| tree | 2c7e2d57de6b7b222b3b805b7adebf0f7bcb2d70 /mm | |
| parent | 3b75a6402747a7bc214366f87cf185949f33cc65 (diff) | |
oom_kill: has_intersects_mems_allowed() needs rcu_read_lock()
At least out_of_memory() calls has_intersects_mems_allowed() without
even rcu_read_lock(), this is obviously buggy.
Add the necessary rcu_read_lock(). This means that we can not simply
return from the loop, we need "bool ret" and "break".
While at it, swap the names of task_struct's (the argument and the
local). This cleans up the code a little bit and avoids the unnecessary
initialization.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Sergey Dyasly <dserrg@gmail.com>
Tested-by: Sergey Dyasly <dserrg@gmail.com>
Reviewed-by: Sameer Nanda <snanda@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: "Ma, Xindong" <xindong.ma@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Iee512a4e3446b1ec8fb7fcc434f1cf18a13a5645
Reviewed-on: http://git-master/r/421704
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Tested-by: Kerwin Wan <kerwinw@nvidia.com>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/oom_kill.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 3a1b1e473001..71da6fa9b186 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -47,18 +47,20 @@ static DEFINE_SPINLOCK(zone_scan_lock); #ifdef CONFIG_NUMA /** * has_intersects_mems_allowed() - check task eligiblity for kill - * @tsk: task struct of which task to consider + * @start: task struct of which task to consider * @mask: nodemask passed to page allocator for mempolicy ooms * * Task eligibility is determined by whether or not a candidate task, @tsk, * shares the same mempolicy nodes as current if it is bound by such a policy * and whether or not it has the same set of allowed cpuset nodes. */ -static bool has_intersects_mems_allowed(struct task_struct *tsk, +static bool has_intersects_mems_allowed(struct task_struct *start, const nodemask_t *mask) { - struct task_struct *start = tsk; + struct task_struct *tsk; + bool ret = false; + rcu_read_lock(); for_each_thread(start, tsk) { if (mask) { /* @@ -67,19 +69,20 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk, * mempolicy intersects current, otherwise it may be * needlessly killed. */ - if (mempolicy_nodemask_intersects(tsk, mask)) - return true; + ret = mempolicy_nodemask_intersects(tsk, mask); } else { /* * This is not a mempolicy constrained oom, so only * check the mems of tsk's cpuset. */ - if (cpuset_mems_allowed_intersects(current, tsk)) - return true; + ret = cpuset_mems_allowed_intersects(current, tsk); } + if (ret) + break; } + rcu_read_unlock(); - return false; + return ret; } #else static bool has_intersects_mems_allowed(struct task_struct *tsk, |