Rafael J. Wysocki said the following on 2009-2-24 5:48: > This message has been generated automatically as a part of a report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.28. Please verify if it still should be listed and let me know > (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12419 > Subject : possible circular locking dependency on i915 dma > Submitter : Wang Chen <wangchen@xxxxxxxxxxxxxx> > Date : 2009-01-08 14:11 (47 days old) > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=546b0974c39657017407c86fe79811100b60700d > References : http://marc.info/?l=linux-kernel&m=123142399720125&w=4 > not changed. ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.29-rc6-default #165 ------------------------------------------------------- X/3940 is trying to acquire lock: (&mm->mmap_sem){----}, at: [<c0168e97>] might_fault+0x42/0x7e but task is already holding lock: (&dev->struct_mutex){--..}, at: [<eeb76fed>] i915_cmdbuffer+0xf4/0x411 [i915] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&dev->struct_mutex){--..}: [<c013791a>] validate_chain+0x8be/0xbb5 [<c0138280>] __lock_acquire+0x66f/0x6f9 [<c0138365>] lock_acquire+0x5b/0x77 [<c02e56fe>] mutex_lock_nested+0xdb/0x244 [<eeb5b03e>] drm_vm_open+0x25/0x37 [drm] [<c011a8b3>] dup_mm+0x247/0x2f2 [<c011b312>] copy_process+0x98c/0xfeb [<c011bac7>] do_fork+0x120/0x29c [<c01016be>] sys_clone+0x25/0x2a [<c0102cdd>] sysenter_do_call+0x12/0x31 [<ffffffff>] 0xffffffff -> #1 (&mm->mmap_sem/1){--..}: [<c013791a>] validate_chain+0x8be/0xbb5 [<c0138280>] __lock_acquire+0x66f/0x6f9 [<c0138365>] lock_acquire+0x5b/0x77 [<c012e6f6>] down_write_nested+0x32/0x4f [<c011a711>] dup_mm+0xa5/0x2f2 [<c011b312>] copy_process+0x98c/0xfeb [<c011bac7>] do_fork+0x120/0x29c [<c01016be>] sys_clone+0x25/0x2a [<c0102cdd>] sysenter_do_call+0x12/0x31 [<ffffffff>] 0xffffffff -> #0 (&mm->mmap_sem){----}: [<c0137625>] validate_chain+0x5c9/0xbb5 [<c0138280>] __lock_acquire+0x66f/0x6f9 [<c0138365>] lock_acquire+0x5b/0x77 [<c0168eb4>] might_fault+0x5f/0x7e [<eeb76d0a>] i915_emit_box+0x1d/0x20c [i915] [<eeb7705e>] i915_cmdbuffer+0x165/0x411 [i915] [<eeb5685b>] drm_ioctl+0x1a6/0x21b [drm] [<c0182b29>] vfs_ioctl+0x3d/0x50 [<c0183029>] do_vfs_ioctl+0x41b/0x483 [<c01830d1>] sys_ioctl+0x40/0x5a [<c0102cdd>] sysenter_do_call+0x12/0x31 [<ffffffff>] 0xffffffff -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html