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: thanks, this works fine. The only issue i still have, is that the dirty_date value starts at 0 and goes to a negative value after reboot. Greets, Stefan -- 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