From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f198.google.com (mail-wj0-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id C62FD6B0038 for ; Mon, 23 Jan 2017 18:04:31 -0500 (EST) Received: by mail-wj0-f198.google.com with SMTP id c7so29319273wjb.7 for ; Mon, 23 Jan 2017 15:04:31 -0800 (PST) Received: from outbound-smtp08.blacknight.com (outbound-smtp08.blacknight.com. [46.22.139.13]) by mx.google.com with ESMTPS id q80si15905900wmg.80.2017.01.23.15.04.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Jan 2017 15:04:30 -0800 (PST) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp08.blacknight.com (Postfix) with ESMTPS id 485121C12C7 for ; Mon, 23 Jan 2017 23:04:30 +0000 (GMT) Date: Mon, 23 Jan 2017 23:04:29 +0000 From: Mel Gorman Subject: Re: [PATCH 3/4] mm, page_alloc: Drain per-cpu pages from workqueue context Message-ID: <20170123230429.os7ssxab4mazrkrb@techsingularity.net> References: <20170117092954.15413-1-mgorman@techsingularity.net> <20170117092954.15413-4-mgorman@techsingularity.net> <06c39883-eff5-1412-a148-b063aa7bcc5f@suse.cz> <20170120152606.w3hb53m2w6thzsqq@techsingularity.net> <20170123170329.GA7820@htj.duckdns.org> <20170123200412.mkesardc4mckk6df@techsingularity.net> <20170123205501.GA25944@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20170123205501.GA25944@htj.duckdns.org> Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Vlastimil Babka , Andrew Morton , Linux Kernel , Linux-MM , Hillf Danton , Jesper Dangaard Brouer , Petr Mladek On Mon, Jan 23, 2017 at 03:55:01PM -0500, Tejun Heo wrote: > Hello, Mel. > > On Mon, Jan 23, 2017 at 08:04:12PM +0000, Mel Gorman wrote: > > What is the actual mechanism that does that? It's not something that > > schedule_on_each_cpu does and one would expect that the core workqueue > > implementation would get this sort of detail correct. Or is this a proposal > > on how it should be done? > > If you use schedule_on_each_cpu(), it's all fine as the thing pins > cpus and waits for all the work items synchronously. If you wanna do > it asynchronously, right now, you'll have to manually synchronize work > items against the offline callback manually. > Is the current implementation and what it does wrong in some way? I ask because synchronising against the offline callback sounds like it would be a bit of a maintenance mess for relatively little gain. -- Mel Gorman 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