On Wed, 11 Jan 2012 19:24:24 -0800 (PST)
David Rientjes <rientjes@xxxxxxxxxx> wrote:
> oom_kill_task() has a single caller, so fold it into its parent function,
> oom_kill_process(). Slightly reduces the number of lines in the oom
> killer.
>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> ---
> mm/oom_kill.c | 87 ++++++++++++++++++++++++++------------------------------
> 1 files changed, 40 insertions(+), 47 deletions(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -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 mem_cgroup *mem)
> -{
> - 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 *mem, nodemask_t *nodemask,
> @@ -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())
> @@ -531,8 +486,46 @@ static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
> }
> } while_each_thread(p, t);
>
> - oom_kill_task(victim, mem);
> + victim = find_lock_task_mm(victim);
> + if (!victim)
> + return;
> +
> + /* mm cannot be safely dereferenced after task_unlock(p) */
> + 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 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(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.
>
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