Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751836AbdFIWir (ORCPT ); Fri, 9 Jun 2017 18:38:47 -0400 Received: from mail-pf0-f174.google.com ([209.85.192.174]:33787 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751761AbdFIWiq (ORCPT ); Fri, 9 Jun 2017 18:38:46 -0400 Date: Fri, 9 Jun 2017 15:38:44 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Michal Hocko cc: Matthew Wilcox , Vlastimil Babka , Larry Finger , Andrew Morton , LKML , linux-mm@kvack.org Subject: Re: Sleeping BUG in khugepaged for i586 In-Reply-To: <20170608203046.GB5535@dhcp22.suse.cz> Message-ID: References: <968ae9a9-5345-18ca-c7ce-d9beaf9f43b6@lwfinger.net> <20170605144401.5a7e62887b476f0732560fa0@linux-foundation.org> <1e883924-9766-4d2a-936c-7a49b337f9e2@lwfinger.net> <9ab81c3c-e064-66d2-6e82-fc9bac125f56@suse.cz> <20170608144831.GA19903@dhcp22.suse.cz> <20170608170557.GA8118@bombadil.infradead.org> <20170608201822.GA5535@dhcp22.suse.cz> <20170608203046.GB5535@dhcp22.suse.cz> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 622 Lines: 14 On Thu, 8 Jun 2017, Michal Hocko wrote: > I would just pull the cond_resched out of __collapse_huge_page_copy > right after pte_unmap. But I am not really sure why this cond_resched is > really needed because the changelog of the patch which adds is is quite > terse on details. I'm not sure what could possibly be added to the changelog. We have encountered need_resched warnings during the iteration. We fix these because need_resched warnings suppress future warnings of the same type for issues that are more important. I can fix the i386 issue but removing the cond_resched() entirely isn't really suitable.