If the request has been completed before the reset took effect, we don't
need to mark it up as being a victim. Touching fence->error after the
fence has been signaled is detected by dma_fence_set_error() and
triggers a BUG:
[ 231.743133] kernel BUG at ./include/linux/dma-fence.h:434!
[ 231.743156] invalid opcode: 0000 [#1] SMP KASAN
[ 231.743172] Modules linked in: i915 drm_kms_helper drm iptable_nat nf_nat_ipv4 nf_nat x86_pkg_temp_thermal iosf_mbi i2c_algo_bit cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea fb font fbdev [last unloaded: drm]
[ 231.743221] CPU: 2 PID: 20 Comm: kworker/2:0 Tainted: G U 4.13.0-rc1+ #52
[ 231.743236] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011
[ 231.743363] Workqueue: events_long i915_hangcheck_elapsed [i915]
[ 231.743382] task: ffff8801f42e9780 task.stack: ffff8801f42f8000
[ 231.743489] RIP: 0010:i915_gem_reset_engine+0x45a/0x460 [i915]
[ 231.743505] RSP: 0018:ffff8801f42ff770 EFLAGS: 00010202
[ 231.743521] RAX: 0000000000000007 RBX: ffff8801bf6b1880 RCX: ffffffffa02881a6
[ 231.743537] RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: ffff8801bf6b18c8
[ 231.743551] RBP: ffff8801f42ff7c8 R08: 0000000000000001 R09: 0000000000000000
[ 231.743566] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801edb02d00
[ 231.743581] R13: ffff8801e19d4200 R14: 000000000000001d R15: ffff8801ce2a4000
[ 231.743599] FS: 0000000000000000(0000) GS:ffff8801f5a80000(0000) knlGS:0000000000000000
[ 231.743614] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 231.743629] CR2: 00007f0ebd1add10 CR3: 0000000002621000 CR4: 00000000000406e0
[ 231.743643] Call Trace:
[ 231.743752] i915_gem_reset+0x6c/0x150 [i915]
[ 231.743853] i915_reset+0x175/0x210 [i915]
[ 231.743958] i915_reset_device+0x33b/0x350 [i915]
[ 231.744061] ? valleyview_pipestat_irq_handler+0xe0/0xe0 [i915]
[ 231.744081] ? trace_hardirqs_off_caller+0x70/0x110
[ 231.744102] ? _raw_spin_unlock_irqrestore+0x46/0x50
[ 231.744120] ? find_held_lock+0x119/0x150
[ 231.744138] ? mark_lock+0x6d/0x850
[ 231.744241] ? gen8_gt_irq_ack+0x1f0/0x1f0 [i915]
[ 231.744262] ? work_on_cpu_safe+0x60/0x60
[ 231.744284] ? rcu_read_lock_sched_held+0x57/0xa0
[ 231.744400] ? gen6_read32+0x2ba/0x320 [i915]
[ 231.744506] i915_handle_error+0x382/0x5f0 [i915]
[ 231.744611] ? gen6_rps_reset_ei+0x20/0x20 [i915]
[ 231.744630] ? vsnprintf+0x128/0x8e0
[ 231.744649] ? pointer+0x6b0/0x6b0
[ 231.744667] ? debug_check_no_locks_freed+0x1a0/0x1a0
[ 231.744688] ? scnprintf+0x92/0xe0
[ 231.744706] ? snprintf+0xb0/0xb0
[ 231.744820] hangcheck_declare_hang+0x15a/0x1a0 [i915]
[ 231.744932] ? engine_stuck+0x440/0x440 [i915]
[ 231.744951] ? rcu_read_lock_sched_held+0x57/0xa0
[ 231.745062] ? gen6_read32+0x2ba/0x320 [i915]
[ 231.745173] ? gen6_read16+0x320/0x320 [i915]
[ 231.745284] ? intel_engine_get_active_head+0x91/0x170 [i915]
[ 231.745401] i915_hangcheck_elapsed+0x3d8/0x400 [i915]
[ 231.745424] process_one_work+0x3e8/0xac0
[ 231.745444] ? pwq_dec_nr_in_flight+0x110/0x110
[ 231.745464] ? do_raw_spin_lock+0x8e/0x120
[ 231.745484] worker_thread+0x8d/0x720
[ 231.745506] kthread+0x19e/0x1f0
[ 231.745524] ? process_one_work+0xac0/0xac0
[ 231.745541] ? kthread_create_on_node+0xa0/0xa0
[ 231.745560] ret_from_fork+0x27/0x40
[ 231.745581] Code: 8b 7d c8 e8 49 0d 02 e1 49 8b 7f 38 48 8b 75 b8 48 83 c7 10 e8 b8 89 be e1 e9 95 fc ff ff 4c 89 e7 e8 4b b9 ff ff e9 30 ff ff ff <0f> 0b 0f 1f 40 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fe
[ 231.745767] RIP: i915_gem_reset_engine+0x45a/0x460 [i915] RSP: ffff8801f42ff770
At first glance this looks to be related to commit c64992e035d7
("drm/i915: Look for active requests earlier in the reset path"), but it
could easily happen before as well. On the other hand, we no longer
logged victims due to the active_request being dropped earlier.
v2: Be trickier to unwind the incomplete request as we cannot rely on
request retirement for the lockless per-engine reset.
v3: Reprobe the active request at the time of the reset.
Reported-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Fixes: c64992e035d7 ("drm/i915: Look for active requests earlier in the reset path")
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Michel Thierry <michel.thierry@xxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem.c | 53 ++++++++++++++++++++++++++---------------
1 file changed, 34 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a9ea83ea321b..6faabf34f142 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2854,11 +2854,9 @@ i915_gem_reset_prepare_engine(struct intel_engine_cs *engine)
if (engine->irq_seqno_barrier)
engine->irq_seqno_barrier(engine);
- if (engine_stalled(engine)) {
- request = i915_gem_find_active_request(engine);
- if (request && request->fence.error == -EIO)
- request = ERR_PTR(-EIO); /* Previous reset failed! */
- }
+ request = i915_gem_find_active_request(engine);
+ if (request && request->fence.error == -EIO)
+ request = ERR_PTR(-EIO); /* Previous reset failed! */
return request;
}
@@ -2927,12 +2925,11 @@ static void engine_skip_context(struct drm_i915_gem_request *request)
spin_unlock_irqrestore(&engine->timeline->lock, flags);
}
-/* Returns true if the request was guilty of hang */
-static bool i915_gem_reset_request(struct drm_i915_gem_request *request)
+/* Returns the request if it was guilty of the hang */
+static struct drm_i915_gem_request *
+i915_gem_reset_request(struct intel_engine_cs *engine,
+ struct drm_i915_gem_request *request)
{
- /* Read once and return the resolution */
- const bool guilty = !i915_gem_request_completed(request);
-
/* The guilty request will get skipped on a hung engine.
*
* Users of client default contexts do not rely on logical
@@ -2954,15 +2951,34 @@ static bool i915_gem_reset_request(struct drm_i915_gem_request *request)
* subsequent hangs.
*/
- if (guilty) {
+ if (engine_stalled(engine)) {
i915_gem_context_mark_guilty(request->ctx);
skip_request(request);
+
+ /* If this context is now banned, skip all pending requests. */
+ if (i915_gem_context_is_banned(request->ctx))
+ engine_skip_context(request);
} else {
- i915_gem_context_mark_innocent(request->ctx);
- dma_fence_set_error(&request->fence, -EAGAIN);
+ /*
+ * Since this is not the hung engine, it may have advanced
+ * since the hang declaration. Double check by refinding
+ * the active request at the time of the reset.
+ */
+ request = i915_gem_find_active_request(engine);
+ if (request) {
+ i915_gem_context_mark_innocent(request->ctx);
+ dma_fence_set_error(&request->fence, -EAGAIN);
+
+ /* Rewind the engine to replay the incomplete rq */
+ spin_lock_irq(&engine->timeline->lock);
+ request = list_prev_entry(request, link);
+ if (&request->link == &engine->timeline->requests)
+ request = NULL;
+ spin_unlock_irq(&engine->timeline->lock);
+ }
}
- return guilty;
+ return request;
}
void i915_gem_reset_engine(struct intel_engine_cs *engine,
@@ -2970,13 +2986,12 @@ void i915_gem_reset_engine(struct intel_engine_cs *engine,
{
engine->irq_posted = 0;
- if (request && i915_gem_reset_request(request)) {
+ if (request)
+ request = i915_gem_reset_request(engine, request);
+
+ if (request) {
DRM_DEBUG_DRIVER("resetting %s to restart from tail of request 0x%x\n",
engine->name, request->global_seqno);
-
- /* If this context is now banned, skip all pending requests. */
- if (i915_gem_context_is_banned(request->ctx))
- engine_skip_context(request);
}
/* Setup the CS to resume from the breadcrumb of the hung request */
--
2.13.3
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
