mm, oom: get rid of signal_struct::oom_victims
After "oom: keep mm of the killed task available" we can safely detect
an oom victim by checking task->signal->oom_mm so we do not need the
signal_struct counter anymore so let's get rid of it.
This alone wouldn't be sufficient for nommu archs because
exit_oom_victim doesn't hide the process from the oom killer anymore.
We can, however, mark the mm with a MMF flag in __mmput. We can reuse
MMF_OOM_REAPED and rename it to a more generic MMF_OOM_SKIP.
Link: http://lkml.kernel.org/r/1472119394-11342-6-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 17946e5..b61357d 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -58,6 +58,11 @@
return p->signal->oom_flag_origin;
}
+static inline bool tsk_is_oom_victim(struct task_struct * tsk)
+{
+ return tsk->signal->oom_mm;
+}
+
extern unsigned long oom_badness(struct task_struct *p,
struct mem_cgroup *memcg, const nodemask_t *nodemask,
unsigned long totalpages);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c4b5883..af07213 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -524,7 +524,7 @@
#define MMF_HAS_UPROBES 19 /* has uprobes */
#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
-#define MMF_OOM_REAPED 21 /* mm has been already reaped */
+#define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
@@ -672,7 +672,6 @@
atomic_t sigcnt;
atomic_t live;
int nr_threads;
- atomic_t oom_victims; /* # of TIF_MEDIE threads in this thread group */
struct list_head thread_head;
wait_queue_head_t wait_chldexit; /* for wait4() */