On Sat, 11 Sep 2010, Jon Masters wrote: > On Sat, 2010-09-11 at 02:51 -0400, Jon Masters wrote: > > On Fri, 2010-09-10 at 19:24 -0600, Stephen John Smoogen wrote: > > > > > Sep 11 01:10:23 fas03 kernel: WARNING: at block/blk-core.c:338 > > > > > Sep 11 01:10:23 fas03 kernel: [<c044fc97>] ? warn_slowpath_common+0x77/0xb0 > > > Sep 11 01:10:23 fas03 kernel: [<c05ca5dc>] ? blk_start_queue+0x6c/0x70 > > > Sep 11 01:10:23 fas03 kernel: [<c044fce3>] ? warn_slowpath_null+0x13/0x20 > > > Sep 11 01:10:23 fas03 kernel: [<c05ca5dc>] ? blk_start_queue+0x6c/0x70 > > > Sep 11 01:10:23 fas03 kernel: [<ed63896b>] ? > > > kick_pending_request_queues+0x1b/0x30 [xen_blkfront] > > > Sep 11 01:10:23 fas03 kernel: [<ed638b80>] ? > > > blkif_interrupt+0x200/0x220 [xen_blkfront] > > > Sep 11 01:10:23 fas03 kernel: [<c04ad7c5>] ? handle_IRQ_event+0x45/0x140 > > > > The code in block/blk-core:338 contains an explicit check to ensure that > > interrupts have been disabled, but this not true since blkif_interrupt > > is not registered with IRQF_DISABLED set at the time of the setup in > > bind_evtchn_to_irqhandler. Thus it might be that interrupts are still on > > when we get to kick_pending_request_queues. Does this always happen? > > > > This perhaps happened because upstream removed IRQF_DISABLED and now > > runs with interrupts disabled in handle_IRQ_event, so Xen won't see > > this. But on 2.6.32 this change had not yet happened. It's also 2:50am > > and I might be reading this wrong, but I at least suggest you open a > > RHEL6 bug and try a more recent kernel build. > > Ah, of course I shouldn't email before bed. There's an obvious giant > spin_lock_irqsave/restore there, but as noted on xen-devel (when they > were mulling over moving all of the blkif_interrupt bits into a tasklet > jut a couple of weeks ago): "It looks like __blk_end_request_all...is > returning with interrupts enabled sometimes". I pinged some folks. > Thanks for looking into this Jon, we happened to have 3 hosts die of this within about 2 hours last night. Here's the bug report Smooge opened: https://bugzilla.redhat.com/show_bug.cgi?id=632802 I'll take a look around for a more recent RHEL6 kernel -Mike _______________________________________________ infrastructure mailing list infrastructure@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/infrastructure
