Messages in this thread | | | Date | Tue, 14 Apr 2009 11:20:37 +0300 | From | Avi Kivity <> | Subject | Re: Problem with kvm on -tip |
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Peter Zijlstra wrote: > On Sat, 2009-04-11 at 15:08 +0300, Avi Kivity wrote: > >>> [ 3293.134688] BUG: MAX_LOCK_DEPTH too low! >>> >>> >> Looks like a genuine issue, need to increase MAX_LOCK_DEPTH. Andrea? >> >> >>> [ 3293.134704] turning off the locking correctness validator. >>> [ 3293.134718] Pid: 5117, comm: kvm Not tainted 2.6.30-rc1-tip-01420-g58e70a8 >>> #18 >>> [ 3293.134727] Call Trace: >>> [ 3293.134749] [<ffffffff802805f6>] __lock_acquire+0x4c6/0xbf0 >>> [ 3293.134764] [<ffffffff80280e2e>] lock_acquire+0x10e/0x160 >>> [ 3293.134780] [<ffffffff802f3760>] ? mm_take_all_locks+0x110/0x150 >>> [ 3293.134798] [<ffffffff80580c3b>] _spin_lock_nest_lock+0x3b/0x50 >>> [ 3293.134811] [<ffffffff802f3760>] ? mm_take_all_locks+0x110/0x150 >>> [ 3293.134823] [<ffffffff802f3760>] mm_take_all_locks+0x110/0x150 >>> [ 3293.134838] [<ffffffff803093af>] do_mmu_notifier_register+0xdf/0x1f0 >>> [ 3293.134852] [<ffffffff803094f3>] mmu_notifier_register+0x13/0x20 >>> [ 3293.134899] [<ffffffffa02edede>] kvm_dev_ioctl+0x1ae/0x360 [kvm] >>> [ 3293.134914] [<ffffffff80327a16>] vfs_ioctl+0x36/0xb0 >>> [ 3293.134927] [<ffffffff80327b22>] do_vfs_ioctl+0x92/0x5c0 >>> [ 3293.134942] [<ffffffff80273d9b>] ? up_read+0x2b/0x40 >>> [ 3293.134955] [<ffffffff8032809f>] sys_ioctl+0x4f/0x80 >>> [ 3293.134971] [<ffffffff8020c1f2>] system_call_fastpath+0x16/0x1b request >>> > > Thing is, its grabbing all vma locks, and we have a lock depth limit of > 48. Now when we started this, the claim was that kvm would only need > this when the process was very fresh and would thus not yet have many > vma, ergo we should never run into this limit. > > Has that changed? >
Hasn't changed; this is on VM creation.
-- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
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