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. Jon. _______________________________________________ infrastructure mailing list infrastructure@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/infrastructure
