From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f200.google.com (mail-wj0-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 217FC6B0038 for ; Fri, 2 Dec 2016 12:15:46 -0500 (EST) Received: by mail-wj0-f200.google.com with SMTP id hb5so46328915wjc.2 for ; Fri, 02 Dec 2016 09:15:46 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id fa9si6069543wjb.103.2016.12.02.09.15.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Dec 2016 09:15:44 -0800 (PST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uB2HAT2T118451 for ; Fri, 2 Dec 2016 12:15:43 -0500 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0b-001b2d01.pphosted.com with ESMTP id 273934ek2u-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 02 Dec 2016 12:15:42 -0500 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 2 Dec 2016 10:15:42 -0700 Date: Fri, 2 Dec 2016 09:15:42 -0800 From: "Paul E. McKenney" Subject: Re: INFO: rcu_sched detected stalls on CPUs/tasks with `kswapd` and `mem_cgroup_shrink_node` Reply-To: paulmck@linux.vnet.ibm.com References: <20161128150509.GG3924@linux.vnet.ibm.com> <66fd50e1-a922-846a-f427-7654795bd4b5@kernelpanic.ru> <20161130174802.GM18432@dhcp22.suse.cz> <20161130182552.GN18432@dhcp22.suse.cz> <20161202164408.GM3924@linux.vnet.ibm.com> <20161202170248.GT6830@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161202170248.GT6830@dhcp22.suse.cz> Message-Id: <20161202171542.GO3924@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Boris Zhmurov , Paul Menzel , Donald Buczek , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Fri, Dec 02, 2016 at 06:02:49PM +0100, Michal Hocko wrote: > On Fri 02-12-16 08:44:08, Paul E. McKenney wrote: > > On Fri, Dec 02, 2016 at 07:39:24PM +0300, Boris Zhmurov wrote: > > > Paul E. McKenney Thu Dec 01 2016 - 14:39:21 EST: > > > > > > >> Well, I can confirm, that replacing cond_resched_rcu_qs in > > > >> shrink_node_memcg by cond_resched also makes dmesg clean from RCU > > > >> CPU stall warnings. > > > >> > > > >> I've attached patch (just modification of Paul's patch), that > > > >> fixes RCU stall messages in situations, when all memory is used by > > > >> couchbase/memcached + fs cache and linux starts to use swap. > > > > > > > Nice! Just to double-check, could you please also test your patch > > > > above with these two commits from -rcu? > > > > > > > > d2db185bfee8 ("rcu: Remove short-term CPU kicking") f8f127e738e3 > > > > ("rcu: Add long-term CPU kicking") > > > > > > > > Thanx, Paul > > > > > > > > > Looks like patches d2db185bfee8 and f8f127e738e3 change nothing. > > > > > > With cond_resched() in shrink_node_memcg and these two patches dmesg is > > > clean. No any RCU CPU stall messages. > > > > Very good! I have these two patches queued for 4.11. > > FWIW I have posted the cond_resched patch to Andrew [1]. I didn't CC you > Paul to save you from emails as this is more MM than anything else > related ;) > > [1] http://lkml.kernel.org/r/20161202095841.16648-1-mhocko@kernel.org Feel free to apply: Acked-by: Paul E. McKenney Thanx, Paul -- 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