drm/i915: Cope with request list state change during error state capture
Subsystems (2)
PATCH v2 3/8 drm/i915: Cope with request list state change during error state capture
Since we're not synchronizing the ring request list during error state capture the request list state might change between the time the corresponding error request list was allocated and dimensioned to the time when the ring request list is actually captured into the error state. If this happens then do an early exit and be aware that the captured error state might not be fully reliable.
* v2:
- Chris Wilson: Removed WARN_ON from size check since having the error state request list and the live driver request list diverge like this is a legitimate behaviour.
- Tomas Elf: Removed update of num_request field since this made no sense. Just exit and move on.
--- drivers/gpu/drm/i915/i915_gpu_error.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
drivers/gpu/drm/i915/i915_gpu_error.c +12 -0
@@ -1071,6 +1071,18 @@ static void i915_gem_record_rings(struct drm_device *dev,list_for_each_entry (request, &ring->request_list, list) {struct drm_i915_error_request *erq; +if (count >= error->ring[i].num_requests) { +/* +* If the ring request list was changed in +* between the point where the error request +* list was created and dimensioned and this +* point then just exit early to avoid crashes. +*/ +DRM_ERROR ("Request list changed size since allocation (%u->%u)\n" , + error->ring[i].num_requests, count); +break ; + } + erq = &error->ring[i].requests[count++]; erq->seqno = request->seqno; erq->jiffies = request->emitted_jiffies;
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1.9.1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Quoted 27 lines · Tomas Elf
Since we're not synchronizing the ring request list during error state capture the request list state might change between the time the corresponding error request list was allocated and dimensioned to the time when the ring request list is actually captured into the error state. If this happens then do an early exit and be aware that the captured error state might not be fully reliable.
* v2:
- Chris Wilson: RemovedWARN_ONfrom size check since having the error state request list and the live driver request list diverge like this is a legitimate behaviour.- Tomas Elf: Removed update of
num_requestfield since this made no sense. Just exit and move on.Signed-off-by Tomas Elf <[email protected]>--- drivers/gpu/drm/i915/i915_gpu_error.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)drivers/gpu/drm/i915/i915_gpu_error.c +0
-0@@ -1071,6 +1071,18 @@ static void i915_gem_record_rings(struct drm_device *dev,list_for_each_entry (request, &ring->request_list, list) {struct drm_i915_error_request *erq;
drivers/gpu/drm/i915/i915_gpu_error.c static void i915_gem_record_rings(struct drm_device *dev, · line 1082
Quoted 10 lines
drivers/gpu/drm/i915/i915_gpu_error.c +9
-0+if (count >= error->ring[i].num_requests) { +/* +* If the ring request list was changed in +* between the point where the error request +* list was created and dimensioned and this +* point then just exit early to avoid crashes. +*/ +DRM_ERROR ("Request list changed size since allocation (%u->%u)\n" , + error->ring[i].num_requests, count);
DRM_ERROR still results in reports about dmesg noise, I think DRM_DEBUG_DRV is the suitable one here.
-Daniel
Quoted 13 lines
drivers/gpu/drm/i915/i915_gpu_error.c +3
-0+break ; + } + erq = &error->ring[i].requests[count++]; erq->seqno = request->seqno; erq->jiffies = request->emitted_jiffies;Signature · 6 lines
1.9.1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
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Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx