On Tue, Aug 20, 2013 at 10:07:45AM +0200, Stefan Priebe - Profihost AG wrote: > Am 20.08.2013 10:01, schrieb Stefan Priebe - Profihost AG: > > Am 20.08.2013 00:27, schrieb Kent Overstreet: > >> On Mon, Aug 19, 2013 at 12:09:24AM +0200, Stefan Priebe wrote: > >>> > >>> Vanilla 3.10.7 + bcache: Fix a writeback performance regression > >>> > >>> http://pastebin.com/raw.php?i=LXZk4cMH > >> > >> Whoops, at first I thought this was the same bug as one I'd already been > >> chasing down that had been a harmless bug - turns out I didn't look > >> closely enough at the backtrace. > >> > >> What happened is background writeback is deadlocking, because for some > >> reason the workqueue it's running out of is a singlethreaded workqueue, > >> so as soon as it decides to queue enough writeback bios that it has to > >> sleep on that semaphore (which often won't happen due to the PD > >> controller based ratelimiting) - boom, deadlock. > >> > >> Here's the fixup patch I just tested and am applying: > > Oh i'm now seeing very high CPU spikes of kworker... i don't see if i > remove bcache: Fix a writeback performance regression. Are you able to reproduce it? I'm not having any luck reproducing it... -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
