From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id CDB9A6B002D for ; Fri, 11 Nov 2011 05:14:19 -0500 (EST) Date: Fri, 11 Nov 2011 10:14:14 +0000 From: Mel Gorman Subject: Re: [PATCH] mm: Do not stall in synchronous compaction for THP allocations Message-ID: <20111111101414.GJ3083@suse.de> References: <20111110100616.GD3083@suse.de> <20111110142202.GE3083@suse.de> <20111110161331.GG3083@suse.de> <20111110151211.523fa185.akpm@linux-foundation.org> 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: David Rientjes Cc: Andrew Morton , Minchan Kim , Jan Kara , Andy Isaacson , Johannes Weiner , Andrea Arcangeli , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu, Nov 10, 2011 at 03:37:32PM -0800, David Rientjes wrote: > On Thu, 10 Nov 2011, Andrew Morton wrote: > > > > This patch once again prevents sync migration for transparent > > > hugepage allocations as it is preferable to fail a THP allocation > > > than stall. > > > > Who said? ;) Presumably some people would prefer to get lots of > > huge pages for their 1000-hour compute job, and waiting a bit to get > > those pages is acceptable. > > > > Indeed. It seems like the behavior would better be controlled with > /sys/kernel/mm/transparent_hugepage/defrag which is set aside specifically > to control defragmentation for transparent hugepages and for that > synchronous compaction should certainly apply. With khugepaged in place, it's adding a tunable that is unnecessary and will not be used. Even if such a tuneable was created, the default behaviour should be "do not stall". -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org