From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 9B9272802FE for ; Fri, 30 Jun 2017 09:58:33 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id p135so34478335ita.11 for ; Fri, 30 Jun 2017 06:58:33 -0700 (PDT) Received: from resqmta-ch2-03v.sys.comcast.net (resqmta-ch2-03v.sys.comcast.net. [2001:558:fe21:29:69:252:207:35]) by mx.google.com with ESMTPS id c66si7596129ioc.232.2017.06.30.06.58.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 30 Jun 2017 06:58:32 -0700 (PDT) Date: Fri, 30 Jun 2017 08:58:30 -0500 (CDT) From: Christoph Lameter Subject: Re: mm/slab: What is cache_reap work for? In-Reply-To: <201706271935.DJJ18719.OMFLFFHJSOVtQO@I-love.SAKURA.ne.jp> Message-ID: References: <201706271935.DJJ18719.OMFLFFHJSOVtQO@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: linux-mm@kvack.org On Tue, 27 Jun 2017, Tetsuo Handa wrote: > I hit an unable to invoke the OOM killer lockup shown below. According to > "cpus=2 node=0 flags=0x0 nice=0" part, it seems that cache_reap (in mm/slab.c) > work stuck waiting for disk_events_workfn (in block/genhd.c) work to complete. Cache reaping in SLAB is the expiration of objects since they are deemed to be cache cold after while. Reaping is a tick driven worker thread that calls other functions that are used during regular slab allocation and freeing. Maybe someone added code that can cause deadlocks if invoked from the tick? -- 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: email@kvack.org