On Tue, Feb 11, 2014 at 06:35:43PM +0000, Russell King - ARM Linux wrote: > The cubox-i4 just hit a new lockdep problem - not quite sure what to > make of this - it looks like an interaction between quite a lot of > locks - I suspect more than the lockdep code is reporting in its > "Possible unsafe locking scenario" report. > > I'm hoping I've sent this to appropriate people... if anyone thinks > this needs to go to someone else, please forward it. Thanks. I didn't dare to look too closely since the console_lock is in the chain, but looks rather similar to http://www.spinics.net/lists/kernel/msg1685909.html akpm is still bikeshedding that one though. -Daniel > > ====================================================== > [ INFO: possible circular locking dependency detected ] > 3.14.0-rc2+ #517 Tainted: G W > ------------------------------------------------------- > Xorg/805 is trying to acquire lock: > (cma_mutex){+.+.+.}, at: [<c03716f4>] dma_release_from_contiguous+0xb8/0xf8 > > but task is already holding lock: > (&dev->struct_mutex){+.+...}, at: [<c03512ec>] drm_gem_object_handle_unreference_unlocked+0xdc/0x148 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > -> #5 (&dev->struct_mutex){+.+...}: > [<c0066f04>] __lock_acquire+0x151c/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c0698180>] mutex_lock_nested+0x5c/0x3ac > [<c0350c30>] drm_gem_mmap+0x40/0xdc > [<c03671d8>] drm_gem_cma_mmap+0x14/0x2c > [<c00ef4f4>] mmap_region+0x3ac/0x59c > [<c00ef9ac>] do_mmap_pgoff+0x2c8/0x370 > [<c00dd730>] vm_mmap_pgoff+0x6c/0x9c > [<c00ee1fc>] SyS_mmap_pgoff+0x54/0x98 > [<c000e6e0>] ret_fast_syscall+0x0/0x48 > -> #4 (&mm->mmap_sem){++++++}: > [<c0066f04>] __lock_acquire+0x151c/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c00e6c5c>] might_fault+0x6c/0x94 > [<c0335440>] con_set_unimap+0x158/0x27c > [<c032f800>] vt_ioctl+0x1298/0x1388 > [<c0323f44>] tty_ioctl+0x168/0xbf4 > [<c0115fac>] do_vfs_ioctl+0x84/0x664 > [<c01165d0>] SyS_ioctl+0x44/0x64 > [<c000e6e0>] ret_fast_syscall+0x0/0x48 > -> #3 (console_lock){+.+.+.}: > [<c0066f04>] __lock_acquire+0x151c/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c006edcc>] console_lock+0x60/0x74 > [<c006f7b8>] console_cpu_notify+0x28/0x34 > [<c004904c>] notifier_call_chain+0x4c/0x8c > [<c004916c>] __raw_notifier_call_chain+0x1c/0x24 > [<c0024124>] __cpu_notify+0x34/0x50 > [<c002424c>] cpu_notify_nofail+0x18/0x24 > [<c068e168>] _cpu_down+0x100/0x244 > [<c068e2dc>] cpu_down+0x30/0x44 > [<c036ef8c>] cpu_subsys_offline+0x14/0x18 > [<c036af28>] device_offline+0x94/0xbc > [<c036b030>] online_store+0x4c/0x74 > [<c0368d3c>] dev_attr_store+0x20/0x2c > [<c016b2e0>] sysfs_kf_write+0x54/0x58 > [<c016eaa4>] kernfs_fop_write+0xc4/0x160 > [<c0105a54>] vfs_write+0xbc/0x184 > [<c0105dfc>] SyS_write+0x48/0x70 > [<c000e6e0>] ret_fast_syscall+0x0/0x48 > -> #2 (cpu_hotplug.lock){+.+.+.}: > [<c0066f04>] __lock_acquire+0x151c/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c0698180>] mutex_lock_nested+0x5c/0x3ac > [<c0024218>] get_online_cpus+0x3c/0x58 > [<c00d0ab0>] lru_add_drain_all+0x24/0x190 > [<c0101d3c>] migrate_prep+0x10/0x18 > [<c00cba04>] alloc_contig_range+0xf4/0x30c > [<c0371588>] dma_alloc_from_contiguous+0x7c/0x130 > [<c0018ef8>] __alloc_from_contiguous+0x38/0x12c > [<c0908694>] atomic_pool_init+0x74/0x128 > [<c0008850>] do_one_initcall+0x3c/0x164 > [<c0903c98>] kernel_init_freeable+0x104/0x1d0 > [<c068de54>] kernel_init+0x10/0xec > [<c000e7a8>] ret_from_fork+0x14/0x2c > -> #1 (lock){+.+...}: > [<c0066f04>] __lock_acquire+0x151c/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c0698180>] mutex_lock_nested+0x5c/0x3ac > [<c00d0aa8>] lru_add_drain_all+0x1c/0x190 > [<c0101d3c>] migrate_prep+0x10/0x18 > [<c00cba04>] alloc_contig_range+0xf4/0x30c > [<c0371588>] dma_alloc_from_contiguous+0x7c/0x130 > [<c0018ef8>] __alloc_from_contiguous+0x38/0x12c > [<c0908694>] atomic_pool_init+0x74/0x128 > [<c0008850>] do_one_initcall+0x3c/0x164 > [<c0903c98>] kernel_init_freeable+0x104/0x1d0 > [<c068de54>] kernel_init+0x10/0xec > [<c000e7a8>] ret_from_fork+0x14/0x2c > -> #0 (cma_mutex){+.+.+.}: > [<c0690850>] print_circular_bug+0x70/0x2f0 > [<c0066f68>] __lock_acquire+0x1580/0x1ca0 > [<c0067c28>] lock_acquire+0xa0/0x130 > [<c0698180>] mutex_lock_nested+0x5c/0x3ac > [<c03716f4>] dma_release_from_contiguous+0xb8/0xf8 > [<c00197a4>] __arm_dma_free.isra.11+0x194/0x218 > [<c0019868>] arm_dma_free+0x1c/0x24 > [<c0366e34>] drm_gem_cma_free_object+0x68/0xb8 > [<c0351194>] drm_gem_object_free+0x30/0x38 > [<c0351318>] drm_gem_object_handle_unreference_unlocked+0x108/0x148 > [<c0351498>] drm_gem_handle_delete+0xb0/0x10c > [<c0351508>] drm_gem_dumb_destroy+0x14/0x18 > [<c035e838>] drm_mode_destroy_dumb_ioctl+0x34/0x40 > [<c034f918>] drm_ioctl+0x3f4/0x498 > [<c0115fac>] do_vfs_ioctl+0x84/0x664 > [<c01165d0>] SyS_ioctl+0x44/0x64 > [<c000e6e0>] ret_fast_syscall+0x0/0x48 > > other info that might help us debug this: > > Chain exists of: cma_mutex --> &mm->mmap_sem --> &dev->struct_mutex > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&dev->struct_mutex); > lock(&mm->mmap_sem); > lock(&dev->struct_mutex); > lock(cma_mutex); > > *** DEADLOCK *** > > 1 lock held by Xorg/805: > #0: (&dev->struct_mutex){+.+...}, at: [<c03512ec>] drm_gem_object_handle_unreference_unlocked+0xdc/0x148 > > stack backtrace: > CPU: 0 PID: 805 Comm: Xorg Tainted: G W 3.14.0-rc2+ #517 > Backtrace: > [<c00124e0>] (dump_backtrace) from [<c0012680>] (show_stack+0x18/0x1c) > r6:c0a869f0 r5:c0a8d540 r4:00000000 r3:00000000 > [<c0012668>] (show_stack) from [<c0693310>] (dump_stack+0x70/0x8c) > [<c06932a0>] (dump_stack) from [<c0690a7c>] (print_circular_bug+0x29c/0x2f0) > r4:c0a79570 r3:e9338980 > [<c06907e0>] (print_circular_bug) from [<c0066f68>] (__lock_acquire+0x1580/0x1ca0) > r10:c0a6da70 r8:e9338dc8 r7:c10ed83c r6:00000001 r5:e9338db0 r4:e9338980 > [<c00659e8>] (__lock_acquire) from [<c0067c28>] (lock_acquire+0xa0/0x130) > r10:00000000 r9:00000002 r8:00000000 r7:00000000 r6:c099e3b0 r5:e8ca2000 > r4:00000000 > [<c0067b88>] (lock_acquire) from [<c0698180>] (mutex_lock_nested+0x5c/0x3ac) > r10:e9338980 r9:ea16d010 r8:e8ca2000 r7:00000000 r6:c0ebe304 r5:c03716f4 > r4:c099e378 > [<c0698124>] (mutex_lock_nested) from [<c03716f4>] (dma_release_from_contiguous+0xb8/0xf8) > r10:ebb00000 r9:ea16d010 r8:c0979cc8 r7:0002bb00 r6:000003fc r5:0003bb00 > r4:c10f4a78 > [<c037163c>] (dma_release_from_contiguous) from [<c00197a4>] (__arm_dma_free.isra.11+0x194/0x218) > r6:003fc000 r5:ea7d8000 r4:ead4e000 r3:c001db4c > [<c0019610>] (__arm_dma_free.isra.11) from [<c0019868>] (arm_dma_free+0x1c/0x24) > r10:e9902e20 r9:e8ca3e38 r8:e989e000 r7:e9902e58 r6:e9902f10 r5:e989e030 > r4:e9aad540 > [<c001984c>] (arm_dma_free) from [<c0366e34>] (drm_gem_cma_free_object+0x68/0xb8) > [<c0366dcc>] (drm_gem_cma_free_object) from [<c0351194>] (drm_gem_object_free+0x30/0x38) > r4:e9aad540 > [<c0351164>] (drm_gem_object_free) from [<c0351318>] (drm_gem_object_handle_unreference_unlocked+0x108/0x148) > [<c0351210>] (drm_gem_object_handle_unreference_unlocked) from [<c0351498>] (drm_gem_handle_delete+0xb0/0x10c) > r5:e9aad540 r4:e9902e00 > [<c03513e8>] (drm_gem_handle_delete) from [<c0351508>] (drm_gem_dumb_destroy+0x14/0x18) > r10:c06e3448 r8:e8ca3e38 r7:e8ca2000 r6:e9902e00 r5:000000b4 r4:e8ca3e38 > [<c03514f4>] (drm_gem_dumb_destroy) from [<c035e838>] (drm_mode_destroy_dumb_ioctl+0x34/0x40) > [<c035e804>] (drm_mode_destroy_dumb_ioctl) from [<c034f918>] (drm_ioctl+0x3f4/0x498) > r4:e989e000 r3:c035e804 > [<c034f524>] (drm_ioctl) from [<c0115fac>] (do_vfs_ioctl+0x84/0x664) > r10:00000000 r9:e8ca2000 r8:beeb6bb4 r7:e9824560 r6:c01165d0 r5:00000006 > r4:e9b97300 > [<c0115f28>] (do_vfs_ioctl) from [<c01165d0>] (SyS_ioctl+0x44/0x64) > r10:00000000 r9:e8ca2000 r8:00000006 r7:c00464b4 r6:beeb6bb4 r5:e9b97300 > r4:00000000 > [<c011658c>] (SyS_ioctl) from [<c000e6e0>] (ret_fast_syscall+0x0/0x48) > r8:c000e8a4 r7:00000036 r6:00000006 r5:c00464b4 r4:beeb6bb4 > > -- > FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation > in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. > Estimate before purchase was "up to 13.2Mbit". > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
