| Message ID | 20230203164937.4035503-1-robdclark@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Move fd_install after last use of fence | expand |
On Fri, Feb 3, 2023 at 8:49 AM Rob Clark <robdclark@gmail.com> wrote: > > From: Rob Clark <robdclark@chromium.org> > > Because eb_composite_fence_create() drops the fence_array reference > after creation of the sync_file, only the sync_file holds a ref to the > fence. But fd_install() makes that reference visable to userspace, so > it must be the last thing we do with the fence. > Fixes: 00dae4d3d35d ("drm/i915: Implement SINGLE_TIMELINE with a syncobj (v4)") > Signed-off-by: Rob Clark <robdclark@chromium.org> > --- > drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > index f266b68cf012..0f2e056c02dd 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > @@ -3476,38 +3476,38 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > err_request: > eb_requests_get(&eb); > err = eb_requests_add(&eb, err); > > if (eb.fences) > signal_fence_array(&eb, eb.composite_fence ? > eb.composite_fence : > &eb.requests[0]->fence); > > + if (unlikely(eb.gem_context->syncobj)) { > + drm_syncobj_replace_fence(eb.gem_context->syncobj, > + eb.composite_fence ? > + eb.composite_fence : > + &eb.requests[0]->fence); > + } > + > if (out_fence) { > if (err == 0) { > fd_install(out_fence_fd, out_fence->file); > args->rsvd2 &= GENMASK_ULL(31, 0); /* keep in-fence */ > args->rsvd2 |= (u64)out_fence_fd << 32; > out_fence_fd = -1; > } else { > fput(out_fence->file); > } > } > > - if (unlikely(eb.gem_context->syncobj)) { > - drm_syncobj_replace_fence(eb.gem_context->syncobj, > - eb.composite_fence ? > - eb.composite_fence : > - &eb.requests[0]->fence); > - } > - > if (!out_fence && eb.composite_fence) > dma_fence_put(eb.composite_fence); > > eb_requests_put(&eb); > > err_vma: > eb_release_vmas(&eb, true); > WARN_ON(err == -EDEADLK); > i915_gem_ww_ctx_fini(&eb.ww); > > -- > 2.38.1 >
On 03/02/2023 18:15, Rob Clark wrote: > On Fri, Feb 3, 2023 at 8:49 AM Rob Clark <robdclark@gmail.com> wrote: >> >> From: Rob Clark <robdclark@chromium.org> >> >> Because eb_composite_fence_create() drops the fence_array reference >> after creation of the sync_file, only the sync_file holds a ref to the >> fence. But fd_install() makes that reference visable to userspace, so >> it must be the last thing we do with the fence. >> > > Fixes: 00dae4d3d35d ("drm/i915: Implement SINGLE_TIMELINE with a syncobj (v4)") This is correct and the fix looks good to me. Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> CI is green so I will merge it, thanks again for a fix Rob! Followup up question for Matthew Brost however is whether the composite fence flow could be simplified. This block here comes late in i915_gem_do_execbuffer and may mislead the user the composite fence is held to the end of the function: if (!out_fence && eb.composite_fence) dma_fence_put(eb.composite_fence); Question is would it work to remove the !out_fence condition from here, and remove "consumption" of the reference from eb_composite_fence_create success path. Regards, Tvrtko >> Signed-off-by: Rob Clark <robdclark@chromium.org> >> --- >> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 14 +++++++------- >> 1 file changed, 7 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c >> index f266b68cf012..0f2e056c02dd 100644 >> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c >> @@ -3476,38 +3476,38 @@ i915_gem_do_execbuffer(struct drm_device *dev, >> >> err_request: >> eb_requests_get(&eb); >> err = eb_requests_add(&eb, err); >> >> if (eb.fences) >> signal_fence_array(&eb, eb.composite_fence ? >> eb.composite_fence : >> &eb.requests[0]->fence); >> >> + if (unlikely(eb.gem_context->syncobj)) { >> + drm_syncobj_replace_fence(eb.gem_context->syncobj, >> + eb.composite_fence ? >> + eb.composite_fence : >> + &eb.requests[0]->fence); >> + } >> + >> if (out_fence) { >> if (err == 0) { >> fd_install(out_fence_fd, out_fence->file); >> args->rsvd2 &= GENMASK_ULL(31, 0); /* keep in-fence */ >> args->rsvd2 |= (u64)out_fence_fd << 32; >> out_fence_fd = -1; >> } else { >> fput(out_fence->file); >> } >> } >> >> - if (unlikely(eb.gem_context->syncobj)) { >> - drm_syncobj_replace_fence(eb.gem_context->syncobj, >> - eb.composite_fence ? >> - eb.composite_fence : >> - &eb.requests[0]->fence); >> - } >> - >> if (!out_fence && eb.composite_fence) >> dma_fence_put(eb.composite_fence); >> >> eb_requests_put(&eb); >> >> err_vma: >> eb_release_vmas(&eb, true); >> WARN_ON(err == -EDEADLK); >> i915_gem_ww_ctx_fini(&eb.ww); >> >> -- >> 2.38.1 >>
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index f266b68cf012..0f2e056c02dd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -3476,38 +3476,38 @@ i915_gem_do_execbuffer(struct drm_device *dev, err_request: eb_requests_get(&eb); err = eb_requests_add(&eb, err); if (eb.fences) signal_fence_array(&eb, eb.composite_fence ? eb.composite_fence : &eb.requests[0]->fence); + if (unlikely(eb.gem_context->syncobj)) { + drm_syncobj_replace_fence(eb.gem_context->syncobj, + eb.composite_fence ? + eb.composite_fence : + &eb.requests[0]->fence); + } + if (out_fence) { if (err == 0) { fd_install(out_fence_fd, out_fence->file); args->rsvd2 &= GENMASK_ULL(31, 0); /* keep in-fence */ args->rsvd2 |= (u64)out_fence_fd << 32; out_fence_fd = -1; } else { fput(out_fence->file); } } - if (unlikely(eb.gem_context->syncobj)) { - drm_syncobj_replace_fence(eb.gem_context->syncobj, - eb.composite_fence ? - eb.composite_fence : - &eb.requests[0]->fence); - } - if (!out_fence && eb.composite_fence) dma_fence_put(eb.composite_fence); eb_requests_put(&eb); err_vma: eb_release_vmas(&eb, true); WARN_ON(err == -EDEADLK); i915_gem_ww_ctx_fini(&eb.ww);