From patchwork Fri Jan 9 11:05:51 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 5598891 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D2829C058D for ; Fri, 9 Jan 2015 11:07:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F19AE204E0 for ; Fri, 9 Jan 2015 11:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21FD020462 for ; Fri, 9 Jan 2015 11:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756693AbbAILHk (ORCPT ); Fri, 9 Jan 2015 06:07:40 -0500 Received: from cantor2.suse.de ([195.135.220.15]:60707 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757239AbbAILGJ (ORCPT ); Fri, 9 Jan 2015 06:06:09 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 99F76AC60; Fri, 9 Jan 2015 11:06:07 +0000 (UTC) From: Michal Hocko To: Andrew Morton Cc: Tejun Heo , "\\\"Rafael J. Wysocki\\\"" , David Rientjes , Johannes Weiner , Oleg Nesterov , Cong Wang , , LKML , linux-pm@vger.kernel.org Subject: [PATCH -v3 1/5] oom: add helpers for setting and clearing TIF_MEMDIE Date: Fri, 9 Jan 2015 12:05:51 +0100 Message-Id: <1420801555-22659-2-git-send-email-mhocko@suse.cz> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1420801555-22659-1-git-send-email-mhocko@suse.cz> References: <1420801555-22659-1-git-send-email-mhocko@suse.cz> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is just a preparatory and it doesn't introduce any functional change. Note: I am utterly unhappy about lowmemory killer abusing TIF_MEMDIE just to wait for the oom victim and to prevent from new killing. This is just a side effect of the flag. The primary meaning is to give the oom victim access to the memory reserves and that shouldn't be necessary here. Signed-off-by: Michal Hocko --- drivers/staging/android/lowmemorykiller.c | 7 ++++++- include/linux/oom.h | 4 ++++ kernel/exit.c | 2 +- mm/memcontrol.c | 2 +- mm/oom_kill.c | 23 ++++++++++++++++++++--- 5 files changed, 32 insertions(+), 6 deletions(-) diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index b545d3d1da3e..feafa172b155 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -160,7 +160,12 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) selected->pid, selected->comm, selected_oom_score_adj, selected_tasksize); lowmem_deathpending_timeout = jiffies + HZ; - set_tsk_thread_flag(selected, TIF_MEMDIE); + /* + * FIXME: lowmemorykiller shouldn't abuse global OOM killer + * infrastructure. There is no real reason why the selected + * task should have access to the memory reserves. + */ + mark_tsk_oom_victim(selected); send_sig(SIGKILL, selected, 0); rem += selected_tasksize; } diff --git a/include/linux/oom.h b/include/linux/oom.h index 76200984d1e2..b42b80f88c3a 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -47,6 +47,10 @@ static inline bool oom_task_origin(const struct task_struct *p) return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN); } +extern void mark_tsk_oom_victim(struct task_struct *tsk); + +extern void unmark_oom_victim(void); + extern unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages); diff --git a/kernel/exit.c b/kernel/exit.c index 287884b05b89..5db52e52c493 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -456,7 +456,7 @@ static void exit_mm(struct task_struct *tsk) task_unlock(tsk); mm_update_next_owner(mm); mmput(mm); - clear_thread_flag(TIF_MEMDIE); + unmark_oom_victim(); } static struct task_struct *find_alive_thread(struct task_struct *p) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0021313d1210..18ecef729597 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1559,7 +1559,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, * quickly exit and free its memory. */ if (fatal_signal_pending(current) || task_will_free_mem(current)) { - set_thread_flag(TIF_MEMDIE); + mark_tsk_oom_victim(current); return; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 294493a7ae4b..80b34e285f96 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -416,6 +416,23 @@ void note_oom_kill(void) atomic_inc(&oom_kills); } +/** + * mark_tsk_oom_victim - marks the given taks as OOM victim. + * @tsk: task to mark + */ +void mark_tsk_oom_victim(struct task_struct *tsk) +{ + set_tsk_thread_flag(tsk, TIF_MEMDIE); +} + +/** + * unmark_oom_victim - unmarks the current task as OOM victim. + */ +void unmark_oom_victim(void) +{ + clear_thread_flag(TIF_MEMDIE); +} + #define K(x) ((x) << (PAGE_SHIFT-10)) /* * Must be called while holding a reference to p, which will be released upon @@ -440,7 +457,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, */ task_lock(p); if (p->mm && task_will_free_mem(p)) { - set_tsk_thread_flag(p, TIF_MEMDIE); + mark_tsk_oom_victim(p); task_unlock(p); put_task_struct(p); return; @@ -495,7 +512,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, /* mm cannot safely be dereferenced after task_unlock(victim) */ mm = victim->mm; - set_tsk_thread_flag(victim, TIF_MEMDIE); + mark_tsk_oom_victim(victim); 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)), @@ -652,7 +669,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, */ if (current->mm && (fatal_signal_pending(current) || task_will_free_mem(current))) { - set_thread_flag(TIF_MEMDIE); + mark_tsk_oom_victim(current); return; }