Messages in this thread | | | From | Linus Torvalds <> | Date | Sun, 5 Feb 2012 14:55:47 -0800 | Subject | Re: [BUG 3.3-rc2] spinlock trylock failure on UP on CPU#0 |
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Ok, interesting. You're triggering the issue because you have a UP build with the spinlock debugging code enabled.
On Sun, Feb 5, 2012 at 12:57 PM, Knut Petersen <Knut_Petersen@t-online.de> wrote: > Booting 23783f817bceedd6d4e549385e3f400ea64059e5 I get the following trace > an AOpen i915GMm-hfs with Pentium-M Dothan:
This is probably the same "technically legal" code that LOCKDEP also is unhappy about - the nested fast path release. We do a trylock on the queue lock while we already are holding the queue lock recursively.
Jens, Tejun - the crazy-ass games that this code is playing is clearly messing not just with lockdep, it's messing with some very reasonable spinlock sanity checks on UP (which just boil down to "a spinlock should never have contention on UP")
Any chance of sanitizing this all?
Linus
> [ 12.526390] BUG: spinlock trylock failure on UP on CPU#0, scsi_id/543 > [ 12.528009] lock: f4ed8830, .magic: dead4ead, .owner: scsi_id/543, .owner_cpu: 0 > [ 12.528009] Pid: 543, comm: scsi_id Not tainted 3.3.0-rc2-main+ #21 > [ 12.528009] Call Trace: > [ 12.528009] [<c043e56d>] spin_dump+0x6c/0x76 > [ 12.528009] [<c043e594>] spin_bug+0x1d/0x21 > [ 12.528009] [<c027739a>] do_raw_spin_trylock+0x33/0x38 > [ 12.528009] [<c04429c2>] _raw_spin_trylock+0x17/0x63 > [ 12.528009] [<c025fafa>] put_io_context+0xa1/0x10a > [ 12.528009] [<c0269d85>] __cfq_slice_expired+0x2f6/0x319 > [ 12.528009] [<c026a8b2>] cfq_dispatch_requests+0x39/0x714 > [ 12.528009] [<c025b328>] elv_drain_elevator+0x3f/0x7d > [ 12.528009] [<c025b3f0>] __elv_add_request+0x8a/0x169 > [ 12.528009] [<c02604a4>] blk_execute_rq_nowait+0x88/0xab > [ 12.528009] [<c0260573>] blk_execute_rq+0xac/0xcd > [ 12.528009] [<c0263cf5>] sg_io+0x23c/0x325 > [ 12.528009] [<c02642a3>] scsi_cmd_ioctl+0x1b1/0x332 > [ 12.528009] [<c0264452>] scsi_cmd_blk_ioctl+0x2e/0x38 > [ 12.528009] [<c035c15e>] sd_ioctl+0xd4/0xf4 > [ 12.528009] [<c02618ce>] __blkdev_driver_ioctl+0x26/0x2e > [ 12.528009] [<c026226a>] blkdev_ioctl+0x70e/0x728 > [ 12.528009] [<c01b3f87>] block_ioctl+0x31/0x39 > [ 12.528009] [<c019ebb9>] do_vfs_ioctl+0x47b/0x4af > [ 12.528009] [<c019ec2e>] sys_ioctl+0x41/0x63 > [ 12.528009] [<c0442c05>] syscall_call+0x7/0xb > > cu, > -kp -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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