From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 7F8026B0038 for ; Sat, 8 Apr 2017 13:04:32 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id n129so98584793pga.22 for ; Sat, 08 Apr 2017 10:04:32 -0700 (PDT) Received: from mail-pf0-x234.google.com (mail-pf0-x234.google.com. [2607:f8b0:400e:c00::234]) by mx.google.com with ESMTPS id h3si8564953pfe.60.2017.04.08.10.04.31 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 08 Apr 2017 10:04:31 -0700 (PDT) Received: by mail-pf0-x234.google.com with SMTP id s16so16708553pfs.0 for ; Sat, 08 Apr 2017 10:04:31 -0700 (PDT) Date: Sat, 8 Apr 2017 10:04:20 -0700 (PDT) From: Hugh Dickins Subject: Re: Is it safe for kthreadd to drain_all_pages? In-Reply-To: Message-ID: References: <20170406130614.a6ygueggpwseqysd@techsingularity.net> <20170407163932.GJ16413@dhcp22.suse.cz> <20170407172918.GK16413@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Michal Hocko , Andrew Morton , Mel Gorman , Tejun Heo , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Fri, 7 Apr 2017, Hugh Dickins wrote: > On Fri, 7 Apr 2017, Michal Hocko wrote: > > On Fri 07-04-17 09:58:17, Hugh Dickins wrote: > > > On Fri, 7 Apr 2017, Michal Hocko wrote: > > > > On Fri 07-04-17 09:25:33, Hugh Dickins wrote: > > > > [...] > > > > > 24 hours so far, and with a clean /var/log/messages. Not conclusive > > > > > yet, and of course I'll leave it running another couple of days, but > > > > > I'm increasingly sure that it works as you intended: I agree that > > > > > > > > > > mm-move-pcp-and-lru-pcp-drainging-into-single-wq.patch > > > > > mm-move-pcp-and-lru-pcp-drainging-into-single-wq-fix.patch > > > > > > > > > > should go to Linus as soon as convenient. Though I think the commit > > > > > message needs something a bit stronger than "Quite annoying though". > > > > > Maybe add a line: > > > > > > > > > > Fixes serious hang under load, observed repeatedly on 4.11-rc. > > > > > > > > Yeah, it is much less theoretical now. I will rephrase and ask Andrew to > > > > update the chagelog and send it to Linus once I've got your final go. > > > > > > I don't know akpm's timetable, but your fix being more than a two-liner, > > > I think it would be better if it could get into rc6, than wait another > > > week for rc7, just in case others then find problems with it. So I > > > think it's safer *not* to wait for my final go, but proceed on the > > > assumption that it will follow a day later. > > > > Fair enough. Andrew, could you update the changelog of > > mm-move-pcp-and-lru-pcp-drainging-into-single-wq.patch > > and send it to Linus along with > > mm-move-pcp-and-lru-pcp-drainging-into-single-wq-fix.patch before rc6? > > > > I would add your Teste-by Hugh but I guess you want to give your testing > > more time before feeling comfortable to give it. > > Yes, fair enough: at the moment it's just > Half-Tested-by: Hugh Dickins > and I hope to take the Half- off in about 21 hours. > But I certainly wouldn't mind if it found its way to Linus without my > final seal of approval. 48 hours and still going well: I declare it good, and thanks to Andrew, Linus has ce612879ddc7 "mm: move pcp and lru-pcp draining into single wq" already in for rc6. Hugh -- 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