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Marek Olšák authored
First this happens: 1) amdgpu_cs_flush (lock bo_fence_lock) -> amdgpu_add_fence_dependency -> os_wait_until_zero (wait for submission_in_progress) - WAITING 2) amdgpu_bo_create -> pb_cache_reclaim_buffer (lock pb_cache::mutex) -> pb_cache_is_buffer_compat -> amdgpu_bo_wait (lock bo_fence_lock) - WAITING So both bo_fence_lock and pb_cache::mutex are held. amdgpu_bo_create can't continue. amdgpu_cs_flush is waiting for the CS ioctl to finish the job, but the CS ioctl is trying to release a buffer: 3) amdgpu_cs_submit_ib (CS thread - job entrypoint) -> amdgpu_cs_context_cleanup -> pb_reference -> pb_destroy -> amdgpu_bo_destroy_or_cache -> pb_cache_add_buffer (lock pb_cache::mutex) - DEADLOCK The simple solution is not to wait for submission_in_progress, which we need in order to create the list of dependencies for the CS ioctl. Instead of building the list of dependencies as a direct input to the CS ioctl, build the list of dependencies as a list of fences, and make the final list of dependencies in the CS thread itself. Therefore, amdgpu_cs_flush doesn't have to wait and can continue. Then, amdgpu_bo_create can continue and return. And then amdgpu_cs_submit_ib can continue. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101294 Cc: 17.1 <mesa-stable@lists.freedesktop.org> Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
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