On Wed, May 20, 2020 at 08:54:36AM +0200, Christian König wrote: > Am 19.05.20 um 15:27 schrieb Daniel Vetter: > > Do it uncontionally, there's a separate peek function with > > dma_fence_is_signalled() which can be called from atomic context. > > > > v2: Consensus calls for an unconditional might_sleep (Chris, > > Christian) > > > > Full audit: > > - dma-fence.h: Uses MAX_SCHEDULE_TIMOUT, good chance this sleeps > > - dma-resv.c: Timeout always at least 1 > > - st-dma-fence.c: Save to sleep in testcases > > - amdgpu_cs.c: Both callers are for variants of the wait ioctl > > - amdgpu_device.c: Two callers in vram recover code, both right next > > to mutex_lock. > > - amdgpu_vm.c: Use in the vm_wait ioctl, next to _reserve/unreserve > > - remaining functions in amdgpu: All for test_ib implementations for > > various engines, caller for that looks all safe (debugfs, driver > > load, reset) > > - etnaviv: another wait ioctl > > - habanalabs: another wait ioctl > > - nouveau_fence.c: hardcoded 15*HZ ... glorious > > - nouveau_gem.c: hardcoded 2*HZ ... so not even super consistent, but > > this one does have a WARN_ON :-/ At least this one is only a > > fallback path for when kmalloc fails. Maybe this should be put onto > > some worker list instead, instead of a work per unamp ... > > - i915/selftests: Hardecoded HZ / 4 or HZ / 8 > > - i915/gt/selftests: Going up the callchain looks safe looking at > > nearby callers > > - i915/gt/intel_gt_requests.c. Wrapped in a mutex_lock > > - i915/gem_i915_gem_wait.c: The i915-version which is called instead > > for i915 fences already has a might_sleep() annotation, so all good > > > > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > > Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > > Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> > > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > > Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> > > Cc: "VMware Graphics" <linux-graphics-maintainer@xxxxxxxxxx> > > Cc: Oded Gabbay <oded.gabbay@xxxxxxxxx> > > Cc: linux-media@xxxxxxxxxxxxxxx > > Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx > > Cc: linux-rdma@xxxxxxxxxxxxxxx > > Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > > Cc: Christian König <christian.koenig@xxxxxxx> > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > > Reviewed-by: Christian König <christian.koenig@xxxxxxx> intel-gfx-ci approves too, thanks to both of you for reviews, patch merged to drm-misc-next. -Daniel > > > --- > > drivers/dma-buf/dma-fence.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > > index 90edf2b281b0..656e9ac2d028 100644 > > --- a/drivers/dma-buf/dma-fence.c > > +++ b/drivers/dma-buf/dma-fence.c > > @@ -208,6 +208,8 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout) > > if (WARN_ON(timeout < 0)) > > return -EINVAL; > > + might_sleep(); > > + > > trace_dma_fence_wait_start(fence); > > if (fence->ops->wait) > > ret = fence->ops->wait(fence, intr, timeout); > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
