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yaml
---
r: 292615
b: refs/heads/master
c: 647f2bd
h: refs/heads/master
i:
  292613: d1c7464
  292611: 9af835c
  292607: e60f2ba
v: v3
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David Rientjes authored and Linus Torvalds committed Mar 22, 2012
1 parent 2ab28ab commit 4b5ac79
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Showing 2 changed files with 39 additions and 48 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 2a1c9b1fc0a0ea2e30cdeb69062647c5c5ae661f
refs/heads/master: 647f2bdf4a00dbcaa8964286501d68e7d2e6da93
85 changes: 38 additions & 47 deletions trunk/mm/oom_kill.c
Original file line number Diff line number Diff line change
Expand Up @@ -434,52 +434,6 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
}

#define K(x) ((x) << (PAGE_SHIFT-10))
static void oom_kill_task(struct task_struct *p)
{
struct task_struct *q;
struct mm_struct *mm;

p = find_lock_task_mm(p);
if (!p)
return;

/* mm cannot be safely dereferenced after task_unlock(p) */
mm = p->mm;

pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
task_pid_nr(p), p->comm, K(p->mm->total_vm),
K(get_mm_counter(p->mm, MM_ANONPAGES)),
K(get_mm_counter(p->mm, MM_FILEPAGES)));
task_unlock(p);

/*
* Kill all user processes sharing p->mm in other thread groups, if any.
* They don't get access to memory reserves or a higher scheduler
* priority, though, to avoid depletion of all memory or task
* starvation. This prevents mm->mmap_sem livelock when an oom killed
* task cannot exit because it requires the semaphore and its contended
* by another thread trying to allocate memory itself. That thread will
* now get access to memory reserves since it has a pending fatal
* signal.
*/
for_each_process(q)
if (q->mm == mm && !same_thread_group(q, p) &&
!(q->flags & PF_KTHREAD)) {
if (q->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
continue;

task_lock(q); /* Protect ->comm from prctl() */
pr_err("Kill process %d (%s) sharing same memory\n",
task_pid_nr(q), q->comm);
task_unlock(q);
force_sig(SIGKILL, q);
}

set_tsk_thread_flag(p, TIF_MEMDIE);
force_sig(SIGKILL, p);
}
#undef K

static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
unsigned int points, unsigned long totalpages,
struct mem_cgroup *memcg, nodemask_t *nodemask,
Expand All @@ -488,6 +442,7 @@ static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
struct task_struct *victim = p;
struct task_struct *child;
struct task_struct *t = p;
struct mm_struct *mm;
unsigned int victim_points = 0;

if (printk_ratelimit())
Expand Down Expand Up @@ -531,8 +486,44 @@ static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
}
} while_each_thread(p, t);

oom_kill_task(victim);
victim = find_lock_task_mm(victim);
if (!victim)
return;

/* mm cannot safely be dereferenced after task_unlock(victim) */
mm = victim->mm;
pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
K(get_mm_counter(victim->mm, MM_ANONPAGES)),
K(get_mm_counter(victim->mm, MM_FILEPAGES)));
task_unlock(victim);

/*
* Kill all user processes sharing victim->mm in other thread groups, if
* any. They don't get access to memory reserves, though, to avoid
* depletion of all memory. This prevents mm->mmap_sem livelock when an
* oom killed thread cannot exit because it requires the semaphore and
* its contended by another thread trying to allocate memory itself.
* That thread will now get access to memory reserves since it has a
* pending fatal signal.
*/
for_each_process(p)
if (p->mm == mm && !same_thread_group(p, victim) &&
!(p->flags & PF_KTHREAD)) {
if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
continue;

task_lock(p); /* Protect ->comm from prctl() */
pr_err("Kill process %d (%s) sharing same memory\n",
task_pid_nr(p), p->comm);
task_unlock(p);
force_sig(SIGKILL, p);
}

set_tsk_thread_flag(victim, TIF_MEMDIE);
force_sig(SIGKILL, victim);
}
#undef K

/*
* Determines whether the kernel must panic because of the panic_on_oom sysctl.
Expand Down

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