From: Jiri Slaby Subject: Re: Excessive stall times on ext4 in 3.9-rc2 Date: Sat, 06 Apr 2013 00:18:11 +0200 Message-ID: <515F4DA3.2000000@suse.cz> References: <20130402142717.GH32241@suse.de> <20130402150651.GB31577@thunk.org> <20130402151436.GC31577@thunk.org> <20130403101925.GA7341@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, LKML , Linux-MM To: Mel Gorman , Theodore Ts'o Return-path: In-Reply-To: <20130403101925.GA7341@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On 04/03/2013 12:19 PM, Mel Gorman wrote: > On Tue, Apr 02, 2013 at 11:14:36AM -0400, Theodore Ts'o wrote: >> On Tue, Apr 02, 2013 at 11:06:51AM -0400, Theodore Ts'o wrote: >>> >>> Can you try 3.9-rc4 or later and see if the problem still persists? >>> There were a number of ext4 issues especially around low memory >>> performance which weren't resolved until -rc4. >> >> Actually, sorry, I took a closer look and I'm not as sure going to >> -rc4 is going to help (although we did have some ext4 patches to fix a >> number of bugs that flowed in as late as -rc4). >> > > I'm running with -rc5 now. I have not noticed much interactivity problems > as such but the stall detection script reported that mutt stalled for > 20 seconds opening an inbox and imapd blocked for 59 seconds doing path > lookups, imaps blocked again for 12 seconds doing an atime update, an RSS > reader blocked for 3.5 seconds writing a file. etc. > > There has been no reclaim activity in the system yet and 2G is still free > so it's very unlikely to be a page or slab reclaim problem. Ok, so now I'm runnning 3.9.0-rc5-next-20130404, it's not that bad, but it still sucks. Updating a kernel in a VM still results in "Your system is too SLOW to play this!" by mplayer and frame dropping. 3.5G out of 6G memory used, the rest is I/O cache. I have 7200RPM disks in my desktop. -- js suse labs