[Nouveau] [bisected] Re: nouveau: lockdep cli->mutex vs reservation_ww_class_mutex deadlock report

Christian König christian.koenig at amd.com
Mon Mar 15 08:05:10 UTC 2021


Hi Mike,

I'm pretty sure your bisection is a bit off.

The patch you mentioned is completely unrelated to Nouveau and I think 
the code path in question is not even used by this driver.

Regards,
Christian.

Am 14.03.21 um 05:48 schrieb Mike Galbraith:
> This little bugger bisected to...
>
> 	b73cd1e2ebfc "drm/ttm: stop destroying pinned ghost object"
>
> ...and (the second time around) was confirmed on the spot.  However,
> while the fingered commit still reverts cleanly, doing so at HEAD does
> not make lockdep return to happy camper state (leading to bisection
> #2), ie the fingered commit is only the beginning of nouveau's 5.12
> cycle lockdep woes.
>
> homer:..kernel/linux-master # quilt applied|grep revert
> patches/revert-drm-ttm-Remove-pinned-bos-from-LRU-in-ttm_bo_move_to_lru_tail-v2.patch
> patches/revert-drm-ttm-cleanup-LRU-handling-further.patch
> patches/revert-drm-ttm-use-pin_count-more-extensively.patch
> patches/revert-drm-ttm-stop-destroying-pinned-ghost-object.patch
>
> That still ain't enough to appease lockdep at HEAD.  I'm not going to
> muck about with it beyond that, since this looks a whole lot like yet
> another example of "fixing stuff exposes other busted stuff".
>
> On Wed, 2021-03-10 at 10:58 +0100, Mike Galbraith wrote:
>> [   29.966927] ======================================================
>> [   29.966929] WARNING: possible circular locking dependency detected
>> [   29.966932] 5.12.0.g05a59d7-master #2 Tainted: G        W   E
>> [   29.966934] ------------------------------------------------------
>> [   29.966937] X/2145 is trying to acquire lock:
>> [   29.966939] ffff888120714518 (&cli->mutex){+.+.}-{3:3}, at: nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.967002]
>>                 but task is already holding lock:
>> [   29.967004] ffff888123c201a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: nouveau_bo_pin+0x2b/0x310 [nouveau]
>> [   29.967053]
>>                 which lock already depends on the new lock.
>>
>> [   29.967056]
>>                 the existing dependency chain (in reverse order) is:
>> [   29.967058]
>>                 -> #1 (reservation_ww_class_mutex){+.+.}-{3:3}:
>> [   29.967063]        __ww_mutex_lock.constprop.16+0xbe/0x10d0
>> [   29.967069]        nouveau_bo_pin+0x2b/0x310 [nouveau]
>> [   29.967112]        nouveau_channel_prep+0x106/0x2e0 [nouveau]
>> [   29.967151]        nouveau_channel_new+0x4f/0x760 [nouveau]
>> [   29.967188]        nouveau_abi16_ioctl_channel_alloc+0xdf/0x350 [nouveau]
>> [   29.967223]        drm_ioctl_kernel+0x91/0xe0 [drm]
>> [   29.967245]        drm_ioctl+0x2db/0x380 [drm]
>> [   29.967259]        nouveau_drm_ioctl+0x56/0xb0 [nouveau]
>> [   29.967303]        __x64_sys_ioctl+0x76/0xb0
>> [   29.967307]        do_syscall_64+0x33/0x40
>> [   29.967310]        entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   29.967314]
>>                 -> #0 (&cli->mutex){+.+.}-{3:3}:
>> [   29.967318]        __lock_acquire+0x1494/0x1ac0
>> [   29.967322]        lock_acquire+0x23e/0x3b0
>> [   29.967325]        __mutex_lock+0x95/0x9d0
>> [   29.967330]        nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.967377]        ttm_bo_handle_move_mem+0x79/0x130 [ttm]
>> [   29.967384]        ttm_bo_validate+0x156/0x1b0 [ttm]
>> [   29.967390]        nouveau_bo_validate+0x48/0x70 [nouveau]
>> [   29.967438]        nouveau_bo_pin+0x1de/0x310 [nouveau]
>> [   29.967487]        nv50_wndw_prepare_fb+0x53/0x4d0 [nouveau]
>> [   29.967531]        drm_atomic_helper_prepare_planes+0x8a/0x110 [drm_kms_helper]
>> [   29.967547]        nv50_disp_atomic_commit+0xa9/0x1b0 [nouveau]
>> [   29.967593]        drm_atomic_helper_update_plane+0x10a/0x150 [drm_kms_helper]
>> [   29.967606]        drm_mode_cursor_universal+0x10b/0x220 [drm]
>> [   29.967627]        drm_mode_cursor_common+0x190/0x200 [drm]
>> [   29.967648]        drm_mode_cursor_ioctl+0x3d/0x50 [drm]
>> [   29.967669]        drm_ioctl_kernel+0x91/0xe0 [drm]
>> [   29.967684]        drm_ioctl+0x2db/0x380 [drm]
>> [   29.967699]        nouveau_drm_ioctl+0x56/0xb0 [nouveau]
>> [   29.967748]        __x64_sys_ioctl+0x76/0xb0
>> [   29.967752]        do_syscall_64+0x33/0x40
>> [   29.967756]        entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   29.967760]
>>                 other info that might help us debug this:
>>
>> [   29.967764]  Possible unsafe locking scenario:
>>
>> [   29.967767]        CPU0                    CPU1
>> [   29.967770]        ----                    ----
>> [   29.967772]   lock(reservation_ww_class_mutex);
>> [   29.967776]                                lock(&cli->mutex);
>> [   29.967779]                                lock(reservation_ww_class_mutex);
>> [   29.967783]   lock(&cli->mutex);
>> [   29.967786]
>>                  *** DEADLOCK ***
>>
>> [   29.967790] 3 locks held by X/2145:
>> [   29.967792]  #0: ffff88810365bcf8 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_mode_cursor_common+0x87/0x200 [drm]
>> [   29.967817]  #1: ffff888108d9e098 (crtc_ww_class_mutex){+.+.}-{3:3}, at: drm_modeset_lock+0xc3/0xe0 [drm]
>> [   29.967841]  #2: ffff888123c201a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: nouveau_bo_pin+0x2b/0x310 [nouveau]
>> [   29.967896]
>>                 stack backtrace:
>> [   29.967899] CPU: 6 PID: 2145 Comm: X Kdump: loaded Tainted: G        W   E     5.12.0.g05a59d7-master #2
>> [   29.967904] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
>> [   29.967908] Call Trace:
>> [   29.967911]  dump_stack+0x6d/0x89
>> [   29.967915]  check_noncircular+0xe7/0x100
>> [   29.967919]  ? nvkm_vram_map+0x48/0x50 [nouveau]
>> [   29.967959]  ? __lock_acquire+0x1494/0x1ac0
>> [   29.967963]  __lock_acquire+0x1494/0x1ac0
>> [   29.967967]  lock_acquire+0x23e/0x3b0
>> [   29.967971]  ? nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.968020]  __mutex_lock+0x95/0x9d0
>> [   29.968024]  ? nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.968070]  ? nvif_vmm_map+0xf4/0x110 [nouveau]
>> [   29.968093]  ? nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.968137]  ? lock_release+0x160/0x280
>> [   29.968141]  ? nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.968184]  nouveau_bo_move+0x11f/0x980 [nouveau]
>> [   29.968226]  ? up_write+0x17/0x130
>> [   29.968229]  ? unmap_mapping_pages+0x53/0x110
>> [   29.968234]  ttm_bo_handle_move_mem+0x79/0x130 [ttm]
>> [   29.968240]  ttm_bo_validate+0x156/0x1b0 [ttm]
>> [   29.968247]  nouveau_bo_validate+0x48/0x70 [nouveau]
>> [   29.968289]  nouveau_bo_pin+0x1de/0x310 [nouveau]
>> [   29.968330]  nv50_wndw_prepare_fb+0x53/0x4d0 [nouveau]
>> [   29.968372]  drm_atomic_helper_prepare_planes+0x8a/0x110 [drm_kms_helper]
>> [   29.968384]  ? lockdep_init_map_type+0x58/0x240
>> [   29.968388]  nv50_disp_atomic_commit+0xa9/0x1b0 [nouveau]
>> [   29.968430]  drm_atomic_helper_update_plane+0x10a/0x150 [drm_kms_helper]
>> [   29.968442]  drm_mode_cursor_universal+0x10b/0x220 [drm]
>> [   29.968463]  ? lock_is_held_type+0xdd/0x130
>> [   29.968468]  drm_mode_cursor_common+0x190/0x200 [drm]
>> [   29.968486]  ? drm_mode_setplane+0x190/0x190 [drm]
>> [   29.968502]  drm_mode_cursor_ioctl+0x3d/0x50 [drm]
>> [   29.968518]  drm_ioctl_kernel+0x91/0xe0 [drm]
>> [   29.968533]  drm_ioctl+0x2db/0x380 [drm]
>> [   29.968548]  ? drm_mode_setplane+0x190/0x190 [drm]
>> [   29.968570]  ? _raw_spin_unlock_irqrestore+0x30/0x60
>> [   29.968574]  ? lockdep_hardirqs_on+0x79/0x100
>> [   29.968578]  ? _raw_spin_unlock_irqrestore+0x3b/0x60
>> [   29.968582]  nouveau_drm_ioctl+0x56/0xb0 [nouveau]
>> [   29.968632]  __x64_sys_ioctl+0x76/0xb0
>> [   29.968636]  ? lockdep_hardirqs_on+0x79/0x100
>> [   29.968640]  do_syscall_64+0x33/0x40
>> [   29.968644]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   29.968648] RIP: 0033:0x7f1ccfb4e9e7
>> [   29.968652] Code: b3 66 90 48 8b 05 b1 14 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 14 2c 00 f7 d8 64 89 01 48
>> [   29.968659] RSP: 002b:00007ffca9596058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
>> [   29.968663] RAX: ffffffffffffffda RBX: 000055da9d0c6470 RCX: 00007f1ccfb4e9e7
>> [   29.968667] RDX: 00007ffca9596090 RSI: 00000000c01c64a3 RDI: 000000000000000e
>> [   29.968670] RBP: 00007ffca9596090 R08: 0000000000000040 R09: 000055da9d0f6310
>> [   29.968674] R10: 0000000000000093 R11: 0000000000000246 R12: 00000000c01c64a3
>> [   29.968677] R13: 000000000000000e R14: 0000000000000000 R15: 0000000000000000
>>



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