From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> To: mhocko@kernel.org Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mgorman@suse.de, rientjes@google.com, torvalds@linux-foundation.org, oleg@redhat.com, hughd@google.com, andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/2] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Date: Fri, 29 Jan 2016 07:26:39 +0900 [thread overview] Message-ID: <201601290726.GGC12497.OSQJVtMFFOHOLF@I-love.SAKURA.ne.jp> (raw) In-Reply-To: <20160128215121.GE621@dhcp22.suse.cz> Michal Hocko wrote: > On Thu 28-01-16 20:24:36, Tetsuo Handa wrote: > [...] > > I like the OOM reaper approach but I can't agree on merging the OOM reaper > > without providing a guaranteed last resort at the same time. If you do want > > to start the OOM reaper as simple as possible (without being bothered by > > a lot of possible corner cases), please pursue a guaranteed last resort > > at the same time. > > I am getting tired of this level of argumentation. oom_reaper in its > current form is a step forward. I have acknowledged there are possible > improvements doable on top but I do not see them necessary for the core > part being merged. I am not trying to rush this in because I am very > well aware of how subtle and complex all the interactions might be. > So please stop your "we must have it all at once" attitude. This is > nothing we have to rush in. We are not talking about a regression which > has to be absolutely fixed in few days. I'm not asking you to merge a perfect version of oom_reaper from the beginning. I know it is too difficult. Instead, I'm asking you to allow using timeout based approaches (shown below) as temporarily workaround because there are environments which cannot wait for oom_reaper to become enough reliable. Would you please reply to the thread which proposed a guaranteed last resort (shown below)? Tetsuo Handa wrote: > I consider phases for managing system-wide OOM events as follows. > > (1) Design and use a system with appropriate memory capacity in mind. > > (2) When (1) failed, the OOM killer is invoked. The OOM killer selects > an OOM victim and allow that victim access to memory reserves by > setting TIF_MEMDIE to it. > > (3) When (2) did not solve the OOM condition, start allowing all tasks > access to memory reserves by your approach. > > (4) When (3) did not solve the OOM condition, start selecting more OOM > victims by my approach. > > (5) When (4) did not solve the OOM condition, trigger the kernel panic. >
WARNING: multiple messages have this Message-ID (diff)
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> To: mhocko@kernel.org Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mgorman@suse.de, rientjes@google.com, torvalds@linux-foundation.org, oleg@redhat.com, hughd@google.com, andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/2] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Date: Fri, 29 Jan 2016 07:26:39 +0900 [thread overview] Message-ID: <201601290726.GGC12497.OSQJVtMFFOHOLF@I-love.SAKURA.ne.jp> (raw) In-Reply-To: <20160128215121.GE621@dhcp22.suse.cz> Michal Hocko wrote: > On Thu 28-01-16 20:24:36, Tetsuo Handa wrote: > [...] > > I like the OOM reaper approach but I can't agree on merging the OOM reaper > > without providing a guaranteed last resort at the same time. If you do want > > to start the OOM reaper as simple as possible (without being bothered by > > a lot of possible corner cases), please pursue a guaranteed last resort > > at the same time. > > I am getting tired of this level of argumentation. oom_reaper in its > current form is a step forward. I have acknowledged there are possible > improvements doable on top but I do not see them necessary for the core > part being merged. I am not trying to rush this in because I am very > well aware of how subtle and complex all the interactions might be. > So please stop your "we must have it all at once" attitude. This is > nothing we have to rush in. We are not talking about a regression which > has to be absolutely fixed in few days. I'm not asking you to merge a perfect version of oom_reaper from the beginning. I know it is too difficult. Instead, I'm asking you to allow using timeout based approaches (shown below) as temporarily workaround because there are environments which cannot wait for oom_reaper to become enough reliable. Would you please reply to the thread which proposed a guaranteed last resort (shown below)? Tetsuo Handa wrote: > I consider phases for managing system-wide OOM events as follows. > > (1) Design and use a system with appropriate memory capacity in mind. > > (2) When (1) failed, the OOM killer is invoked. The OOM killer selects > an OOM victim and allow that victim access to memory reserves by > setting TIF_MEMDIE to it. > > (3) When (2) did not solve the OOM condition, start allowing all tasks > access to memory reserves by your approach. > > (4) When (3) did not solve the OOM condition, start selecting more OOM > victims by my approach. > > (5) When (4) did not solve the OOM condition, trigger the kernel panic. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-01-28 22:26 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-06 15:42 [PATCH 0/2 -mm] oom reaper v4 Michal Hocko 2016-01-06 15:42 ` Michal Hocko 2016-01-06 15:42 ` [PATCH 1/2] mm, oom: introduce oom reaper Michal Hocko 2016-01-06 15:42 ` Michal Hocko 2016-01-07 11:23 ` Tetsuo Handa 2016-01-07 11:23 ` Tetsuo Handa 2016-01-07 12:30 ` Michal Hocko 2016-01-07 12:30 ` Michal Hocko 2016-01-11 22:54 ` Andrew Morton 2016-01-11 22:54 ` Andrew Morton 2016-01-12 8:16 ` Michal Hocko 2016-01-12 8:16 ` Michal Hocko 2016-01-28 1:28 ` David Rientjes 2016-01-28 1:28 ` David Rientjes 2016-01-28 21:42 ` Michal Hocko 2016-01-28 21:42 ` Michal Hocko 2016-02-02 3:02 ` David Rientjes 2016-02-02 3:02 ` David Rientjes 2016-02-02 8:57 ` Michal Hocko 2016-02-02 8:57 ` Michal Hocko 2016-02-02 11:48 ` Tetsuo Handa 2016-02-02 11:48 ` Tetsuo Handa 2016-02-02 22:55 ` David Rientjes 2016-02-02 22:55 ` David Rientjes 2016-02-02 22:51 ` David Rientjes 2016-02-02 22:51 ` David Rientjes 2016-02-03 10:31 ` Tetsuo Handa 2016-02-03 10:31 ` Tetsuo Handa 2016-01-06 15:42 ` [PATCH 2/2] oom reaper: handle anonymous mlocked pages Michal Hocko 2016-01-06 15:42 ` Michal Hocko 2016-01-07 8:14 ` Michal Hocko 2016-01-07 8:14 ` Michal Hocko 2016-01-11 12:42 ` [PATCH 3/2] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Michal Hocko 2016-01-11 12:42 ` Michal Hocko 2016-01-11 16:52 ` Johannes Weiner 2016-01-11 16:52 ` Johannes Weiner 2016-01-11 17:46 ` Michal Hocko 2016-01-11 17:46 ` Michal Hocko 2016-02-15 10:58 ` Tetsuo Handa 2016-02-15 10:58 ` Tetsuo Handa 2016-01-18 4:35 ` Tetsuo Handa 2016-01-18 4:35 ` Tetsuo Handa 2016-01-18 10:22 ` Tetsuo Handa 2016-01-18 10:22 ` Tetsuo Handa 2016-01-26 16:38 ` Michal Hocko 2016-01-26 16:38 ` Michal Hocko 2016-01-28 11:24 ` Tetsuo Handa 2016-01-28 11:24 ` Tetsuo Handa 2016-01-28 21:51 ` Michal Hocko 2016-01-28 21:51 ` Michal Hocko 2016-01-28 22:26 ` Tetsuo Handa [this message] 2016-01-28 22:26 ` Tetsuo Handa 2016-01-28 22:36 ` Michal Hocko 2016-01-28 22:36 ` Michal Hocko 2016-01-28 22:33 ` Michal Hocko 2016-01-28 22:33 ` Michal Hocko
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