From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx147.postini.com [74.125.245.147]) by kanga.kvack.org (Postfix) with SMTP id 1CEE26B004F for ; Fri, 16 Dec 2011 17:56:02 -0500 (EST) Date: Fri, 16 Dec 2011 14:56:00 -0800 From: Andrew Morton Subject: Re: [PATCH 0/11] Reduce compaction-related stalls and improve asynchronous migration of dirty pages v6 Message-Id: <20111216145600.908fc77e.akpm@linux-foundation.org> In-Reply-To: <1323877293-15401-1-git-send-email-mgorman@suse.de> References: <1323877293-15401-1-git-send-email-mgorman@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrea Arcangeli , Minchan Kim , Dave Jones , Jan Kara , Andy Isaacson , Johannes Weiner , Rik van Riel , Nai Xia , Linux-MM , LKML On Wed, 14 Dec 2011 15:41:22 +0000 Mel Gorman wrote: > Short summary: There are severe stalls when a USB stick using VFAT > is used with THP enabled that are reduced by this series. If you are > experiencing this problem, please test and report back and considering > I have seen complaints from openSUSE and Fedora users on this as well > as a few private mails, I'm guessing it's a widespread issue. This > is a new type of USB-related stall because it is due to synchronous > compaction writing where as in the past the big problem was dirty > pages reaching the end of the LRU and being written by reclaim. > > Am cc'ing Andrew this time and this series would replace > mm-do-not-stall-in-synchronous-compaction-for-thp-allocations.patch. > I'm also cc'ing Dave Jones as he might have merged that patch to Fedora > for wider testing and ideally it would be reverted and replaced by > this series. So it appears that the problem is painful for distros and users and that we won't have this fixed until 3.2 at best, and that fix will be a difficult backport for distributors of earlier kernels. To serve those people better, I'm wondering if we should merge mm-do-not-stall-in-synchronous-compaction-for-thp-allocations now, make it available for -stable backport and then revert it as part of this series? ie: give people a stopgap while we fix it properly? -- 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