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| author | Grazvydas Ignotas <notasas@gmail.com> | 2016-10-23 21:31:43 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-18 10:51:53 +0100 |
| commit | 25ed6e4b0b651d84cc88e1347d34d186f45146ec (patch) | |
| tree | 0e3ac6205acbccd3b9908d132ef6ed5c99d85984 | |
| parent | de5e9aa77a3c4a4a340a2e7191912222bfd34ec4 (diff) | |
| download | lwn-25ed6e4b0b651d84cc88e1347d34d186f45146ec.tar.gz lwn-25ed6e4b0b651d84cc88e1347d34d186f45146ec.zip | |
drm/amdgpu: fix fence slab teardown
commit 0f10425e811355986907c54f7d1d06703e406092 upstream.
To free fences, call_rcu() is used, which calls amdgpu_fence_free()
after a grace period. During teardown, there is no guarantee all
callbacks have finished, so amdgpu_fence_slab may be destroyed before
all fences have been freed. If we are lucky, this results in some slab
warnings, if not, we get a crash in one of rcu threads because callback
is called after amdgpu has already been unloaded.
Fix it with a rcu_barrier().
Fixes: b44135351a3a ("drm/amdgpu: RCU protected amdgpu_fence_release")
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 0b109aebfec6..c82b95b838d0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -68,6 +68,7 @@ int amdgpu_fence_slab_init(void) void amdgpu_fence_slab_fini(void) { + rcu_barrier(); kmem_cache_destroy(amdgpu_fence_slab); } /* |