Don Zickus <dzickus@xxxxxxxxxx> writes: > On Thu, Oct 27, 2011 at 02:43:22PM -0400, Jeff Moyer wrote: >> >> This doesn't look like the same problem. Here we've got BUG: scheduling >> >> while atomic. If it was the bug fixed by the above commits, then you >> >> would hit a BUG_ON. I would start looking at the btrfs bits to see if >> >> they're holding any locks in this code path. >> > >> > Ignore that one and move to IMG_0350.IMG. 'scheduling while atomic' is >> > just noise. Besides Mike and Vivek told me to blame you for not pushing >> > Jens harder on these fixes. :-))))) >> >> I'm looking at 0355, which shows the very top of the trace, and that >> says BUG: scheduling while atomic. So the problem reported here *is* >> different from the one fixed by the above two commits. In fact, I don't >> see evidence of the multipath + flush issue in any of these pictures. > > You have to ignore the 'schedule while atomic' thing it is just a > > printk("BUG: scheduling while atomic"), it is _not_ a BUG(). :-) > (hint read kernel/sched.c::__schedule_bug) > > I see those messages all the time, it really should be a WARN and not a > misleading BUG, but whatever. > > His machine died because the NMI watchdog detected a lockup. The lockup > was because in blk_insert_cloned_request(), spin_lock_irqsave disabled > interrupts and spun forever waiting on the q->queue_lock (IMG_0350.JPG). > > Mike and Vivek both said that is what you fixed for 3.2. They also said > the only caller of blk_insert_cloned_request() is multipath, hence that > argument. I'll cc them. Or maybe I can have them walk over to your cube. > :-) Well then they know more than I do. The bug I fixed would not result in infinite spinning on the queue lock. It resulted in a BUG_ON in blk_insert_flush, since req->bio was NULL. So again, I really don't see how this is related. We could put this all to rest by asking the victim to try out those two patches. Cheers, Jeff _______________________________________________ kernel mailing list kernel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/kernel