On 03/31/2011 07:33 AM, Jens Axboe wrote: > On 2011-03-31 14:11, Tejun Heo wrote: >> Hello, >> >> On Thu, Mar 31, 2011 at 12:37:42PM +0200, Jens Axboe wrote: >>> It seems to hard hang, looks very odd: >> I think more likely failure mode is something is looping in block path >> expecting someone else to do something but as it is busy looping and >> preemption isn't enabled the someone else can't proceed. We had a >> similar problem in md lately. >> >> http://thread.gmane.org/gmane.linux.raid/33020 > > I think this sound exactly right, and also explains why SMP works. And > yes CONFIG_PREEMPT_VOLUNTARY=y is set. > >> If this is the case, a good way to debug would be triggering sysrq-l >> multiple times while the machine is hung and see where the CPU is busy >> looping. > > Doesn't respond to sysrq. I'll poke around. Pulled and retested, still hanging for me right after announcing ext3. Just FYI. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
