From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f72.google.com (mail-it0-f72.google.com [209.85.214.72]) by kanga.kvack.org (Postfix) with ESMTP id E17896B037E for ; Wed, 5 Jul 2017 10:08:05 -0400 (EDT) Received: by mail-it0-f72.google.com with SMTP id v193so145168661itc.10 for ; Wed, 05 Jul 2017 07:08:05 -0700 (PDT) Received: from resqmta-ch2-09v.sys.comcast.net (resqmta-ch2-09v.sys.comcast.net. [2001:558:fe21:29:69:252:207:41]) by mx.google.com with ESMTPS id 194si24117327itz.9.2017.07.05.07.08.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Jul 2017 07:08:04 -0700 (PDT) Date: Wed, 5 Jul 2017 09:08:01 -0500 (CDT) From: Christoph Lameter Subject: Re: mm/slab: What is cache_reap work for? In-Reply-To: <201707042215.ICG90672.FStFMFQOHLOOJV@I-love.SAKURA.ne.jp> Message-ID: References: <201706271935.DJJ18719.OMFLFFHJSOVtQO@I-love.SAKURA.ne.jp> <201707042215.ICG90672.FStFMFQOHLOOJV@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, 4 Jul 2017, Tetsuo Handa wrote: > Thank you for explanation. What I observed is that it seems that > cache_reap work was not able to run because it used system_wq when > the system was unable to allocate memory for new worker thread due to > infinite too_many_isolated() loop in shrink_inactive_list(). Its ok for it not to run for awhile but that potentially traps memory. And you want more memory to be freed. > I wondered whether cache_reap work qualifies as an mm_percpu_wq user > if cache_reap work does something like what vmstat_work work does (e.g. > update statistic counters which affect progress of memory allocation). > But "calls other functions that are used during regular slab allocation" > means cache_reap work cannot qualify as an mm_percpu_wq user... Well if you audit the functions called then you may be able to get there. -- 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