> > > so to me it looks like lockdep at least has the appearance of moaning > > about a reasonably fishy situation... > > To me it looks more about lockdep complaining because it doesn't grok > the full picture. The question is how to shut it up. ok that is quite possible. But I do think you read the original output incorrectly so let me at least phrase it in english: __queue_lock is used in softirq context like this: [<c0361c59>] _spin_lock+0x29/0x40 [<c029fa24>] scsi_device_unbusy+0x64/0x90 [<c029a5bc>] scsi_finish_command+0x1c/0xa0 [<c02115c2>] blk_done_softirq+0x62/0x70 [<c0122a27>] __do_softirq+0x87/0x100 [<c0122af5>] do_softirq+0x55/0x60 [<c0122f3c>] ksoftirqd+0x7c/0xd0 [<c0130f76>] kthread+0xf6/0x100 which means that it always has to be taken _irq / _irqsave and one never can enable interrupts while holding this lock. This backtrace is from the first time the lock was taken in irq context. Now a new situation has arisen that violates this constraint, and it looks like this: [<c0219091>] cfq_set_request+0x351/0x3b0 [<c020c7fc>] elv_set_request+0x1c/0x40 [<c020fcff>] get_request+0x23f/0x270 [<c0210537>] get_request_wait+0x27/0x120 [<c02107ca>] __make_request+0x5a/0x350 [<c020f40f>] generic_make_request+0x16f/0x220 [<c02117e4>] submit_bio+0x64/0x110 now cfq_set_request() uses several inlines which muddies the situation, but lockdep claims one of them is not done correctly. (eg either it takes the lock incorrectly or something does spin_unlock_irq while the lock is held) I get the impression you assumed lockdep was complaining about scsi_device_unbusy; but it's not; that function is only referenced since it's the first place since boot where the lock was taken in softirq context... not because the violation is occuring there. -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org - 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
