Re: [PATCH] mm/page_alloc: Wait for oom_lock before retrying.
From: Sergey Senozhatsky <hidden>
Date: 2016-12-14 10:20:23
On (12/14/16 10:37), Petr Mladek wrote: [..]
quoted
---------- [ 450.767693] Out of memory: Kill process 14642 (a.out) score 999 or sacrifice child [ 450.769974] Killed process 14642 (a.out) total-vm:4168kB, anon-rss:84kB, file-rss:0kB, shmem-rss:0kB [ 450.776538] oom_reaper: reaped process 14642 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB [ 450.781170] Out of memory: Kill process 14643 (a.out) score 999 or sacrifice child [ 450.783469] Killed process 14643 (a.out) total-vm:4168kB, anon-rss:84kB, file-rss:0kB, shmem-rss:0kB [ 450.787912] oom_reaper: reaped process 14643 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB [ 450.792630] Out of memory: Kill process 14644 (a.out) score 999 or sacrifice child [ 450.964031] a.out: page allocation stalls for 10014ms, order:0, mode:0x24280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO) [ 450.964033] CPU: 0 PID: 14622 Comm: a.out Tainted: G W 4.9.0+ #99 (...snipped...) [ 740.984902] a.out: page allocation stalls for 300003ms, order:0, mode:0x24280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO) [ 740.984905] CPU: 0 PID: 14622 Comm: a.out Tainted: G W 4.9.0+ #99 ---------- Although it is fine to make warn_alloc() less verbose, this is not a problem which can be avoided by simply reducing printk(). Unless we give enough CPU time to the OOM killer and OOM victims, it is trivial to lockup the system.You could try to use printk_deferred() in warn_alloc(). It will not handle console. It will help to be sure that the blocked printk() is the main problem.
I thought about deferred printk, but I'm afraid in the given conditions this has great chances to badly lockup the system. -ss -- 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>