From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754407AbbA0KpT (ORCPT ); Tue, 27 Jan 2015 05:45:19 -0500 Received: from cantor2.suse.de ([195.135.220.15]:44875 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752054AbbA0KpN (ORCPT ); Tue, 27 Jan 2015 05:45:13 -0500 Date: Tue, 27 Jan 2015 11:45:11 +0100 From: Michal Hocko To: Vinayak Menon Cc: Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov@parallels.com, mgorman@suse.de, minchan@kernel.org Subject: Re: [PATCH v2] mm: vmscan: fix the page state calculation in too_many_isolated Message-ID: <20150127104511.GB19880@dhcp22.suse.cz> References: <1421235419-30736-1-git-send-email-vinmenon@codeaurora.org> <20150114165036.GI4706@dhcp22.suse.cz> <54B7F7C4.2070105@codeaurora.org> <20150116154922.GB4650@dhcp22.suse.cz> <54BA7D3A.40100@codeaurora.org> <20150126172832.GC22681@dhcp22.suse.cz> <54C76995.70501@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54C76995.70501@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 27-01-15 16:03:57, Vinayak Menon wrote: [...] > Sure, I can retest. Thanks! > Even without highly overloaded workqueues, there can be a delay of HZ in > updating the counters. This means reclaim path can be blocked for a second > or more, when there aren't really any isolated pages. So we need the fix in > too_many_isolated also right ? Is this a big deal though? What you are hitting is certainly a corner case. I assume your system is trashing heavily already with so few pages on the file LRU list. Anyway as mentioned in other email I would rather see vmstat data more reliable than spread hacks to the code where we see immediate issues. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f171.google.com (mail-wi0-f171.google.com [209.85.212.171]) by kanga.kvack.org (Postfix) with ESMTP id 551A26B0032 for ; Tue, 27 Jan 2015 05:45:14 -0500 (EST) Received: by mail-wi0-f171.google.com with SMTP id l15so3769314wiw.4 for ; Tue, 27 Jan 2015 02:45:13 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id ft7si1415545wjb.169.2015.01.27.02.45.12 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 27 Jan 2015 02:45:13 -0800 (PST) Date: Tue, 27 Jan 2015 11:45:11 +0100 From: Michal Hocko Subject: Re: [PATCH v2] mm: vmscan: fix the page state calculation in too_many_isolated Message-ID: <20150127104511.GB19880@dhcp22.suse.cz> References: <1421235419-30736-1-git-send-email-vinmenon@codeaurora.org> <20150114165036.GI4706@dhcp22.suse.cz> <54B7F7C4.2070105@codeaurora.org> <20150116154922.GB4650@dhcp22.suse.cz> <54BA7D3A.40100@codeaurora.org> <20150126172832.GC22681@dhcp22.suse.cz> <54C76995.70501@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54C76995.70501@codeaurora.org> Sender: owner-linux-mm@kvack.org List-ID: To: Vinayak Menon Cc: Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov@parallels.com, mgorman@suse.de, minchan@kernel.org On Tue 27-01-15 16:03:57, Vinayak Menon wrote: [...] > Sure, I can retest. Thanks! > Even without highly overloaded workqueues, there can be a delay of HZ in > updating the counters. This means reclaim path can be blocked for a second > or more, when there aren't really any isolated pages. So we need the fix in > too_many_isolated also right ? Is this a big deal though? What you are hitting is certainly a corner case. I assume your system is trashing heavily already with so few pages on the file LRU list. Anyway as mentioned in other email I would rather see vmstat data more reliable than spread hacks to the code where we see immediate issues. -- Michal Hocko SUSE Labs -- 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