From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f197.google.com (mail-wj0-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 4E1F06B0038 for ; Wed, 30 Nov 2016 13:25:55 -0500 (EST) Received: by mail-wj0-f197.google.com with SMTP id jb2so34062948wjb.6 for ; Wed, 30 Nov 2016 10:25:55 -0800 (PST) Received: from mail-wj0-f193.google.com (mail-wj0-f193.google.com. [209.85.210.193]) by mx.google.com with ESMTPS id m141si8258196wmd.20.2016.11.30.10.25.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Nov 2016 10:25:54 -0800 (PST) Received: by mail-wj0-f193.google.com with SMTP id jb2so23476640wjb.3 for ; Wed, 30 Nov 2016 10:25:54 -0800 (PST) Date: Wed, 30 Nov 2016 19:25:52 +0100 From: Michal Hocko Subject: Re: INFO: rcu_sched detected stalls on CPUs/tasks with `kswapd` and `mem_cgroup_shrink_node` Message-ID: <20161130182552.GN18432@dhcp22.suse.cz> References: <20161125212000.GI31360@linux.vnet.ibm.com> <20161128095825.GI14788@dhcp22.suse.cz> <20161128105425.GY31360@linux.vnet.ibm.com> <3a4242cb-0198-0a3b-97ae-536fb5ff83ec@kernelpanic.ru> <20161128143435.GC3924@linux.vnet.ibm.com> <20161128150509.GG3924@linux.vnet.ibm.com> <66fd50e1-a922-846a-f427-7654795bd4b5@kernelpanic.ru> <20161130174802.GM18432@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Boris Zhmurov Cc: paulmck@linux.vnet.ibm.com, Paul Menzel , Donald Buczek , linux-mm@kvack.org On Wed 30-11-16 21:12:52, Boris Zhmurov wrote: > Michal Hocko 30/11/16 20:48: > > >> Well, after some testing I may say, that your patch: > >> ---------------------8<----------------------------------- > >> commit 7cebc6b63bf75db48cb19a94564c39294fd40959 > >> Author: Paul E. McKenney > >> Date: Fri Nov 25 12:48:10 2016 -0800 > >> > >> mm: Prevent shrink_node_memcg() RCU CPU stall warnings > >> ---------------------8<----------------------------------- > >> > >> fixes stall warning and dmesg is clean now. > > > > Do I get it right that s@cond_resched_rcu_qs@cond_resched@ didn't help? > > I didn't try that. I've tried 4 patches from Paul's linux-rcu tree. > I can try another portion of patches, no problem :) Replacing cond_resched_rcu_qs in shrink_node_memcg by cond_resched would be really helpful to tell whether we are missing a real scheduling point or whether something more serious is going on here. -- 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