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 0C49F6B0038 for ; Wed, 7 Dec 2016 11:45:57 -0500 (EST) Received: by mail-wj0-f198.google.com with SMTP id j10so86104989wjb.3 for ; Wed, 07 Dec 2016 08:45:57 -0800 (PST) Received: from outbound-smtp04.blacknight.com (outbound-smtp04.blacknight.com. [81.17.249.35]) by mx.google.com with ESMTPS id d82si9166702wmd.67.2016.12.07.08.45.55 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 07 Dec 2016 08:45:55 -0800 (PST) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp04.blacknight.com (Postfix) with ESMTPS id 8C05098DD0 for ; Wed, 7 Dec 2016 16:45:55 +0000 (UTC) Date: Wed, 7 Dec 2016 16:45:54 +0000 From: Mel Gorman Subject: Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Message-ID: <20161207164554.b73qjfxy2w3h3ycr@techsingularity.net> References: <20161207101228.8128-1-mgorman@techsingularity.net> <20161207155750.yfsizliaoodks5k4@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , Michal Hocko , Vlastimil Babka , Johannes Weiner , Jesper Dangaard Brouer , Joonsoo Kim , Linux-MM , Linux-Kernel On Wed, Dec 07, 2016 at 10:40:47AM -0600, Christoph Lameter wrote: > On Wed, 7 Dec 2016, Mel Gorman wrote: > > > Which is related to the fundamentals of fragmentation control in > > general. At some point there will have to be a revisit to get back to > > the type of reliability that existed in 3.0-era without the massive > > overhead it incurred. As stated before, I agree it's important but > > outside the scope of this patch. > > What reliability issues are there? 3.X kernels were better in what > way? Which overhead are we talking about? > 3.0-era kernels had better fragmentation control, higher success rates at allocation etc. I vaguely recall that it had fewer sources of high-order allocations but I don't remember specifics and part of that could be the lack of THP at the time. The overhead was massive due to massive stalls and excessive reclaim -- hours to complete some high-allocation stress tests even if the success rate was high. -- 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