From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ric Wheeler Subject: Re: Hang running fs_mark Date: Thu, 25 Sep 2008 17:10:37 -0400 Message-ID: <48DBFE4D.6080100@redhat.com> References: <20080925175643.GA14205@unused.rdu.redhat.com> <1222367822.7028.55.camel@think.oraclecorp.com> <20080925183435.GB14205@unused.rdu.redhat.com> <1222369531.7028.58.camel@think.oraclecorp.com> <48DBF693.20501@redhat.com> <1222376682.7028.80.camel@think.oraclecorp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Josef Bacik , linux-btrfs@vger.kernel.org To: Chris Mason Return-path: In-Reply-To: <1222376682.7028.80.camel@think.oraclecorp.com> List-ID: Chris Mason wrote: > On Thu, 2008-09-25 at 16:37 -0400, Ric Wheeler wrote: > >> Chris Mason wrote: >> >>> On Thu, 2008-09-25 at 14:34 -0400, Josef Bacik wrote: >>> >>> >>>> On Thu, Sep 25, 2008 at 02:37:02PM -0400, Chris Mason wrote: >>>> >>>> >>>>> On Thu, 2008-09-25 at 13:56 -0400, Josef Bacik wrote: >>>>> >>>>> >>>>>> Hello, >>>>>> >>>>>> Reporting this on behalf of ric. He was running the following fs_mark command >>>>>> >>>>>> ./fs_mark -d /mnt/test -s 20480 -D 64 -t 8 -F >>>>>> >>>>>> Seems it hung and wasn't making any progress. He managed to get some sysrq-t, >>>>>> which is at http://people.redhat.com/jwhiter/fs-mark-hang.txt towards the bottom >>>>>> of the document. He could ctrl+c and unmount the fs so its not a hard hang. >>>>>> Looks like we've just locked up behind a page lock somewhere. I have to run off >>>>>> to class so I can't look into it too deeply so throwing this out there hoping >>>>>> somebody else figures it out :). Thanks, >>>>>> >>>>>> >>>>> Which kernel was this? >>>>> > > >> It actually cleaned up very nicely after I killed the fs_mark processes >> & unmounted the btrfs file system. Before doing that, the box was >> sluggish and had the feeling of a system with something that might have >> been spinning (but that is just an observation, not measured in any >> strict sense). >> > > Ok, I have that fs_mark test running here. How far did yours get before > it stopped? > > -chris > > I had gone (in heavy fsync mode) up to about 8 million files on a 1TB s-ata disk: 17 8064000 20480 5.6 15301404 This is the new (no system sync() call) Chris special fs_mark. The rate had been quite reasonable, starting out at around 160 20k files/sec, went under 100 files/sec at around 3 million files and then fell under 50 files/sec at around 7.5 million before hitting this really low speed at just under 8 million. Maybe it really was not hung, just extremely slow... ric