Am 12.05.20 um 10:59 schrieb Daniel Vetter:
This is a bit tricky, since ->notifier_lock is held while calling dma_fence_wait we must ensure that also the read side (i.e. dma_fence_begin_signalling) is on the same side. If we mix this up lockdep complaints, and that's again why we want to have these annotations.
A nice side effect of this is that because of the fs_reclaim priming for dma_fence_enable lockdep now automatically checks for us that nothing in here allocates memory, without even running any userptr workloads.
Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Christian König christian.koenig@amd.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 7653f62b1b2d..6db3f3c629b0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1213,6 +1213,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, struct amdgpu_job *job; uint64_t seq; int r;
- bool fence_cookie;
job = p->job; p->job = NULL; @@ -1227,6 +1228,8 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, */ mutex_lock(&p->adev->notifier_lock);
- fence_cookie = dma_fence_begin_signalling();
- /* If userptr are invalidated after amdgpu_cs_parser_bos(), return
*/
- -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl.
@@ -1264,12 +1267,14 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm); ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence);
- dma_fence_end_signalling(fence_cookie);
Mhm, this could come earlier in theory. E.g. after pushing the job to the scheduler.
Christian.
mutex_unlock(&p->adev->notifier_lock); return 0; error_abort: drm_sched_job_cleanup(&job->base);
- dma_fence_end_signalling(fence_cookie); mutex_unlock(&p->adev->notifier_lock);
error_unlock: