On Mon, Jun 25, 2012 at 11:38:38AM -0600, Stefan Priebe wrote: > > Am 25.06.2012 16:48, schrieb Josef Bacik: > > On Mon, Jun 25, 2012 at 08:45:02AM -0600, Stefan Priebe - Profihost AG > > wrote: > >>> > >>> Thats weird, sysrq+w should have a bunch of stacktraces but it's empty, so > >>> unless theres a bug theres nothing blocked. Is the box actually hung or > >>> is it > >>> just taking forever? Maybe try sysrq+w again to see if the one you > >>> pasted was > >>> just a fluke? Thanks, > >> > >> This one looks better: > >> http://pastebin.com/raw.php?i=R4pztDRt > >> > > > > Ok looks like you have discard turned on. > Yes > > > Can you turn that off and see if you > > can still reproduce the deadlock? If so sysrq+w again, if not then I know > > where > > to look ;). Thanks, > without discard i can't reproduce but random write speed with ceph > without discard is a LOT slower (around 8000 iops/s instead of > 13000iops/s). So i don't know if it is discard or if i'm just not able > to trigger it. >
Ouch, what kind of drive goes faster with discard _on_? Anyway it looks like we're waiting for the discard to come back, so either its your drive or theres a bug in the block layer. Maybe try an older kernel and see if it's broken there, and then bisect it down? Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
