From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f72.google.com (mail-pa0-f72.google.com [209.85.220.72]) by kanga.kvack.org (Postfix) with ESMTP id 75671828E1 for ; Wed, 22 Jun 2016 18:42:10 -0400 (EDT) Received: by mail-pa0-f72.google.com with SMTP id fg1so109893420pad.1 for ; Wed, 22 Jun 2016 15:42:10 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id x129si2308039pfb.98.2016.06.22.15.42.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Jun 2016 15:42:09 -0700 (PDT) Date: Wed, 22 Jun 2016 15:42:07 -0700 From: Andrew Morton Subject: Re: [patch] mm, compaction: abort free scanner if split fails Message-Id: <20160622154207.a65d48bae9e90cc1e89f3895@linux-foundation.org> In-Reply-To: References: <20160622145617.79197acff1a7e617b9d9d393@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Vlastimil Babka , Minchan Kim , Joonsoo Kim , Mel Gorman , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org On Wed, 22 Jun 2016 15:06:29 -0700 (PDT) David Rientjes wrote: > On Wed, 22 Jun 2016, Andrew Morton wrote: > > > On Tue, 21 Jun 2016 18:22:49 -0700 (PDT) David Rientjes wrote: > > > > > If the memory compaction free scanner cannot successfully split a free > > > page (only possible due to per-zone low watermark), terminate the free > > > scanner rather than continuing to scan memory needlessly. If the > > > watermark is insufficient for a free page of order <= cc->order, then > > > terminate the scanner since all future splits will also likely fail. > > > > > > This prevents the compaction freeing scanner from scanning all memory on > > > very large zones (very noticeable for zones > 128GB, for instance) when > > > all splits will likely fail while holding zone->lock. > > > > > > > This collides pretty heavily with Joonsoo's "mm/compaction: split > > freepages without holding the zone lock". > > > > Sorry if it wasn't clear, but I was proposing this patch for 4.7 > inclusion and Vlastimil agreed we should ask for that. Joonsoo said he > was prepared to rebase on top of that. Is > mm-compaction-split-freepages-without-holding-the-zone-lock.patch and > friends going into 4.7 or are we deferring this fix until 4.8? I have this patch lined up for 4.7 so I was rebasing Joonsoo's patches on top. -- 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