[Intel-gfx] [PATCH 13/27] drm/i915/guc: Take context ref when cancelling request
A context can get destroyed after cancelling a request, if a context or GT reset occurs, so take a reference to context when cancelling a request. Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") Signed-off-by: Matthew Brost Reviewed-by: Daniele Ceraolo Spurio --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 5844bb954922..1cb97e98871c 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1630,8 +1630,10 @@ static void guc_context_cancel_request(struct intel_context *ce, struct i915_request *rq) { if (i915_sw_fence_signaled(&rq->submit)) { - struct i915_sw_fence *fence = guc_context_block(ce); + struct i915_sw_fence *fence; + intel_context_get(ce); + fence = guc_context_block(ce); i915_sw_fence_wait(fence); if (!i915_request_completed(rq)) { __i915_request_skip(rq); @@ -1646,6 +1648,7 @@ static void guc_context_cancel_request(struct intel_context *ce, flush_work(&ce_to_guc(ce)->ct.requests.worker); guc_context_unblock(ce); + intel_context_put(ce); } } -- 2.32.0
Re: [Intel-gfx] [PATCH 13/27] drm/i915/guc: Take context ref when cancelling request
On 8/24/2021 8:42 AM, Matthew Brost wrote: On Fri, Aug 20, 2021 at 05:07:27PM -0700, Daniele Ceraolo Spurio wrote: On 8/18/2021 11:16 PM, Matthew Brost wrote: A context can get destroyed after cancelling a request so take a reference to context when cancelling a request. What's the exact race? AFAICS __i915_request_skip does not have a context_put(). This commit message isn't quite right, it is really a context reset or a GT reset which could result in the context getting destroyed. I haven't actually seen this happen but this just being paranoid about ref counting. Can fix up the commit message. ok, with an updated commit message: Reviewed-by: Daniele Ceraolo Spurio Daniele Matt Daniele Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") Signed-off-by: Matthew Brost --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index e0e85e4ad512..85f96d325048 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1620,8 +1620,10 @@ static void guc_context_cancel_request(struct intel_context *ce, struct i915_request *rq) { if (i915_sw_fence_signaled(&rq->submit)) { - struct i915_sw_fence *fence = guc_context_block(ce); + struct i915_sw_fence *fence; + intel_context_get(ce); + fence = guc_context_block(ce); i915_sw_fence_wait(fence); if (!i915_request_completed(rq)) { __i915_request_skip(rq); @@ -1636,6 +1638,7 @@ static void guc_context_cancel_request(struct intel_context *ce, flush_work(&ce_to_guc(ce)->ct.requests.worker); guc_context_unblock(ce); + intel_context_put(ce); } }
Re: [Intel-gfx] [PATCH 13/27] drm/i915/guc: Take context ref when cancelling request
On Fri, Aug 20, 2021 at 05:07:27PM -0700, Daniele Ceraolo Spurio wrote: > > > On 8/18/2021 11:16 PM, Matthew Brost wrote: > > A context can get destroyed after cancelling a request so take a > > reference to context when cancelling a request. > > What's the exact race? AFAICS __i915_request_skip does not have a > context_put(). This commit message isn't quite right, it is really a context reset or a GT reset which could result in the context getting destroyed. I haven't actually seen this happen but this just being paranoid about ref counting. Can fix up the commit message. Matt > > Daniele > > > > > Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") > > Signed-off-by: Matthew Brost > > --- > > drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 - > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > index e0e85e4ad512..85f96d325048 100644 > > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > @@ -1620,8 +1620,10 @@ static void guc_context_cancel_request(struct > > intel_context *ce, > >struct i915_request *rq) > > { > > if (i915_sw_fence_signaled(&rq->submit)) { > > - struct i915_sw_fence *fence = guc_context_block(ce); > > + struct i915_sw_fence *fence; > > + intel_context_get(ce); > > + fence = guc_context_block(ce); > > i915_sw_fence_wait(fence); > > if (!i915_request_completed(rq)) { > > __i915_request_skip(rq); > > @@ -1636,6 +1638,7 @@ static void guc_context_cancel_request(struct > > intel_context *ce, > > flush_work(&ce_to_guc(ce)->ct.requests.worker); > > guc_context_unblock(ce); > > + intel_context_put(ce); > > } > > } >
Re: [Intel-gfx] [PATCH 13/27] drm/i915/guc: Take context ref when cancelling request
On 8/18/2021 11:16 PM, Matthew Brost wrote: A context can get destroyed after cancelling a request so take a reference to context when cancelling a request. What's the exact race? AFAICS __i915_request_skip does not have a context_put(). Daniele Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") Signed-off-by: Matthew Brost --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index e0e85e4ad512..85f96d325048 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1620,8 +1620,10 @@ static void guc_context_cancel_request(struct intel_context *ce, struct i915_request *rq) { if (i915_sw_fence_signaled(&rq->submit)) { - struct i915_sw_fence *fence = guc_context_block(ce); + struct i915_sw_fence *fence; + intel_context_get(ce); + fence = guc_context_block(ce); i915_sw_fence_wait(fence); if (!i915_request_completed(rq)) { __i915_request_skip(rq); @@ -1636,6 +1638,7 @@ static void guc_context_cancel_request(struct intel_context *ce, flush_work(&ce_to_guc(ce)->ct.requests.worker); guc_context_unblock(ce); + intel_context_put(ce); } }
[Intel-gfx] [PATCH 13/27] drm/i915/guc: Take context ref when cancelling request
A context can get destroyed after cancelling a request so take a reference to context when cancelling a request. Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") Signed-off-by: Matthew Brost --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index e0e85e4ad512..85f96d325048 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1620,8 +1620,10 @@ static void guc_context_cancel_request(struct intel_context *ce, struct i915_request *rq) { if (i915_sw_fence_signaled(&rq->submit)) { - struct i915_sw_fence *fence = guc_context_block(ce); + struct i915_sw_fence *fence; + intel_context_get(ce); + fence = guc_context_block(ce); i915_sw_fence_wait(fence); if (!i915_request_completed(rq)) { __i915_request_skip(rq); @@ -1636,6 +1638,7 @@ static void guc_context_cancel_request(struct intel_context *ce, flush_work(&ce_to_guc(ce)->ct.requests.worker); guc_context_unblock(ce); + intel_context_put(ce); } } -- 2.32.0