On 25/07/2019 14:14, Chris Wilson wrote:
Modifying a remote context requires careful serialisation with requests on that context, and that serialisation requires us to take their timeline->mutex. Make it so.Note that while struct_mutex rules, we can't create more than one request in parallel, but that age is soon coming to an end. v2: Though it doesn't affect the current users, contexts may share timelines so check if we already hold the right mutex. Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com> --- drivers/gpu/drm/i915/gt/intel_context.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index 9292b6ca5e9c..d64b45f7ec6d 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -254,10 +254,18 @@ int intel_context_prepare_remote_request(struct intel_context *ce, /* Only suitable for use in remotely modifying this context */ GEM_BUG_ON(rq->hw_context == ce);- /* Queue this switch after all other activity by this context. */- err = i915_active_request_set(&tl->last_request, rq); - if (err) - return err; + if (rq->timeline != tl) { /* beware timeline sharing */ + err = mutex_lock_interruptible_nested(&tl->mutex, + SINGLE_DEPTH_NESTING); + if (err) + return err; + + /* Queue this switch after current activity by this context. */ + err = i915_active_request_set(&tl->last_request, rq); + if (err) + goto unlock; + } + lockdep_assert_held(&tl->mutex);/** Guarantee context image and the timeline remains pinned until the @@ -267,7 +275,12 @@ int intel_context_prepare_remote_request(struct intel_context *ce, * words transfer the pinned ce object to tracked active request. */ GEM_BUG_ON(i915_active_is_idle(&ce->active)); - return i915_active_ref(&ce->active, rq->fence.context, rq); + err = i915_active_ref(&ce->active, rq->fence.context, rq); + +unlock: + if (rq->timeline != tl) + mutex_unlock(&tl->mutex); + return err; }struct i915_request *intel_context_create_request(struct intel_context *ce)
Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com> Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
