David found another issue with priority bumping from mmioflips, where we
are accessing the requests concurrently to them being retired and freed.
Whilst we are skipping the dependency if has been submitted, that is not
sufficient to stop the dependency from disappearing if another thread
retires that request. To prevent we can either employ the struct_mutex (or a
request mutex in the future) to serialise retiring before it is freed.
Alternatively, we need to keep the dependencies alive using RCU whilst
they are being accessed via the DFS.
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.698111] general protection fault:
0000 [#1] PREEMPT SMP
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.698305] Modules linked in:
snd_hda_intel snd_hda_codec snd_hwdep x86_pkg_temp_thermal snd_hda_core
coretemp crct10dif_pclmul crc32_pclmul snd_pcm ghash_clmulni_intel mei_me mei
i915 e1000e ptp pps_core i2c_hid
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.698750] CPU: 1 PID: 6716 Comm:
kworker/u8:2 Not tainted 4.9.0-rc6-CI-Nightly_816+ #1
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.698871] Hardware name: GIGABYTE
GB-BKi7A-7500/MFLP7AP-00, BIOS F1 07/27/2016
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699125] Workqueue: events_unbound
intel_mmio_flip_work_func [i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699266] task: ffff880260a5e800
task.stack: ffffc90000f6c000
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699361] RIP:
0010:[<ffffffffa006595d>] [<ffffffffa006595d>] execlists_schedule+0x8d/0x300
[i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699632] RSP: 0018:ffffc90000f6fcd8
EFLAGS: 00010206
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699724] RAX: dead0000000000f8 RBX:
ffff8801f64b2bf0 RCX: ffff8801f64b2c10
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699842] RDX: dead000000000100 RSI:
0000000000000000 RDI: ffff8801f64b0458
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.699972] RBP: ffffc90000f6fd68 R08:
ffff88026488dc00 R09: 0000000000000002
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700090] R10: 0000000000000000 R11:
0000000000000000 R12: 0000000000000400
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700195] R13: ffffc90000f6fcf0 R14:
ffff88020955aa40 R15: ffff88020955aa68
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700307] FS: 0000000000000000(0000)
GS:ffff88026dc80000(0000) knlGS:0000000000000000
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700435] CS: 0010 DS: 0000 ES: 0000
CR0: 0000000080050033
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700532] CR2: 0000000002a69e90 CR3:
0000000002c07000 CR4: 00000000003406e0
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700635] Stack:
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700682] ffff880260a5e880
ffffc90000f6fd50 ffffffff810af69a ffffc90000f6fd28
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700827] ffff88020955a628
ffff8801e1eaebf0 0000000000000020 0000000000000000
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.700947] 00000196af1edc96
ffff88025dfa4000 ffff8801f0b030a8 ffffc90000f6fcf0
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701071] Call Trace:
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701117] [<ffffffff810af69a>] ?
dequeue_entity+0x25a/0xb50
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701260] [<ffffffffa00516be>]
fence_set_priority+0x7e/0x80 [i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701406] [<ffffffffa0051a15>]
i915_gem_object_wait_priority+0x85/0x160 [i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701599] [<ffffffffa008ccd7>]
intel_mmio_flip_work_func+0x47/0x2b0 [i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701717] [<ffffffff81094c4d>]
process_one_work+0x14d/0x470
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701809] [<ffffffff81094fb3>]
worker_thread+0x43/0x4e0
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701888] [<ffffffff81094f70>] ?
process_one_work+0x470/0x470
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.701969] [<ffffffff81094f70>] ?
process_one_work+0x470/0x470
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702072] [<ffffffff8109a4d5>]
kthread+0xc5/0xe0
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702152] [<ffffffff81771c59>] ?
_raw_spin_unlock_irq+0x9/0x10
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702234] [<ffffffff8109a410>] ?
kthread_park+0x60/0x60
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702318] [<ffffffff81772272>]
ret_from_fork+0x22/0x30
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702387] Code: 89 42 08 48 8b 45 88 48
89 55 c0 4c 89 6d c8 4c 8d 70 d8 4d 8d 7e 28 4d 39 ef 74 72 49 8b 1e 48 8b 13
48 39 d3 48 8d 42 f8 74 3e <48> 8b 10 8b 52 38 41 39 d4 7e 26 48 8b 50 30 48 8b
78 28 48 8d
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.702921] RIP [<ffffffffa006595d>]
execlists_schedule+0x8d/0x300 [i915]
Nov 25 21:42:54 kbl-gbbki7 kernel: [ 1746.703027] RSP <ffffc90000f6fcd8>
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711015] ---[ end trace
4ecf3ae63087e670 ]---
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711023] BUG: unable to handle kernel
NULL pointer dereference at 000000000000000b
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711070] IP: [<ffffffff810baf76>]
__wake_up_common+0x26/0x80
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711104] PGD 25df92067
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711119] PUD 25b1f0067
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711134] PMD 0
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711140]
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711151] Oops: 0000 [#2] PREEMPT SMP
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711172] Modules linked in:
snd_hda_intel snd_hda_codec snd_hwdep x86_pkg_temp_thermal snd_hda_core
coretemp crct10dif_pclmul crc32_pclmul snd_pcm ghash_clmulni_intel mei_me mei
i915 e1000e ptp pps_core i2c_hid
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711298] CPU: 1 PID: 6716 Comm:
kworker/u8:2 Tainted: G D 4.9.0-rc6-CI-Nightly_816+ #1
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711342] Hardware name: GIGABYTE
GB-BKi7A-7500/MFLP7AP-00, BIOS F1 07/27/2016
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711386] task: ffff880260a5e800
task.stack: ffffc90000f6c000
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711415] RIP:
0010:[<ffffffff810baf76>] [<ffffffff810baf76>] __wake_up_common+0x26/0x80
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711449] RSP: 0018:ffffc90000f6fe50
EFLAGS: 00010092
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711464] RAX: 0000000000000282 RBX:
ffffc90000f6ff18 RCX: 0000000000000000
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711484] RDX: 000000000000000b RSI:
0000000000000003 RDI: ffffc90000f6ff18
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711503] RBP: ffffc90000f6fe88 R08:
0000000000000000 R09: 0000000000000005
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711522] R10: 00000000ffffffff R11:
00000000000002cb R12: ffffc90000f6ff20
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711541] R13: 0000000000000282 R14:
0000000000000000 R15: 0000000000000003
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711561] FS: 0000000000000000(0000)
GS:ffff88026dc80000(0000) knlGS:0000000000000000
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711583] CS: 0010 DS: 0000 ES: 0000
CR0: 0000000080050033
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711599] CR2: 0000000000000028 CR3:
0000000263b53000 CR4: 00000000003406e0
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711617] Stack:
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711624] 0000000100f6fe60
0000000000000000 ffffc90000f6ff18 ffffc90000f6ff10
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711650] 0000000000000282
0000000000000000 ffff88020955aa68 ffffc90000f6fe98
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711674] ffffffff810bb02e
ffffc90000f6fec0 ffffffff810bb8d2 ffff880260a5ee40
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711701] Call Trace:
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711710] [<ffffffff810bb02e>]
__wake_up_locked+0xe/0x10
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711726] [<ffffffff810bb8d2>]
complete+0x32/0x50
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711757] [<ffffffff8107a1a8>]
mm_release+0xb8/0x140
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711773] [<ffffffff81080e6b>]
do_exit+0x28b/0xae0
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711789] [<ffffffff81773f17>]
rewind_stack_do_exit+0x17/0x20
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711806] Code: 5d c3 0f 1f 00 55 48 89
e5 41 57 41 56 41 55 41 54 4c 8d 67 08 53 41 89 f7 48 83 ec 10 89 55 cc 48 8b
57 08 4c 89 45 d0 49 39 d4 <48> 8b 32 74 45 41 89 ce 48 8d 42 e8 4c 8d 6e e8 eb
03 49 89 d5
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.711937] RIP [<ffffffff810baf76>]
__wake_up_common+0x26/0x80
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.713142] RSP <ffffc90000f6fe50>
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.714340] CR2: 000000000000000b
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.715439] ---[ end trace
4ecf3ae63087e671 ]---
Nov 25 21:44:11 kbl-gbbki7 kernel: [ 1746.715441] Fixing recursive fault but
reboot is needed!
Fixes: 27745e829a5c ("drm/i915/execlists: Use a local lock for dfs_link access")
Fixes: 9a151987d709 ("drm/i915: Add execution priority boosting for mmioflips")
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: David Weinehall <david.weineh...@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index 77c4ff9efbe3..7a4f7730877a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12022,7 +12022,6 @@ static void intel_mmio_flip_work_func(struct
work_struct *w)
to_intel_framebuffer(crtc->base.primary->fb);
struct drm_i915_gem_object *obj = intel_fb->obj;
- i915_gem_object_wait_priority(obj, 0, I915_PRIORITY_DISPLAY);
WARN_ON(i915_gem_object_wait(obj, 0, MAX_SCHEDULE_TIMEOUT, NULL) < 0);
intel_pipe_update_start(crtc);
@@ -12278,6 +12277,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
i915_add_request_no_flush(request);
}
+ i915_gem_object_wait_priority(obj, 0, I915_PRIORITY_DISPLAY);
i915_gem_track_fb(intel_fb_obj(old_fb), obj,
to_intel_plane(primary)->frontbuffer_bit);
mutex_unlock(&dev->struct_mutex);
--
2.10.2
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