| Message ID | 20211216142749.1966107-9-maarten.lankhorst@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Remove short term pins from execbuf by requiring lock to unbind. | expand |
On Thu, 16 Dec 2021 at 14:28, Maarten Lankhorst <maarten.lankhorst@linux.intel.com> wrote: > > Now that we cannot unbind kill the currently locked object directly "unbind kill" > because we're removing short term pinning, we may have to unbind the > object from gtt manually, using a i915_gem_evict_vm() call. > > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Maybe mention that this only in preparation for some future patches, once the actual eviction is trylock and evict_for_vm can also handle shared dma-resv? At this point in the series we shouldn't expect to hit -ENOSPC, right? > --- > drivers/gpu/drm/i915/gem/i915_gem_mman.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c > index af81d6c3332a..00cd9642669a 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c > @@ -358,8 +358,22 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) > vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); > } > > - /* The entire mappable GGTT is pinned? Unexpected! */ > - GEM_BUG_ON(vma == ERR_PTR(-ENOSPC)); > + /* > + * The entire mappable GGTT is pinned? Unexpected! > + * Try to evict the object we locked too, as normally we skip it > + * due to lack of short term pinning inside execbuf. > + */ > + if (vma == ERR_PTR(-ENOSPC)) { > + ret = mutex_lock_interruptible(&ggtt->vm.mutex); > + if (!ret) { > + ret = i915_gem_evict_vm(&ggtt->vm); > + mutex_unlock(&ggtt->vm.mutex); > + } > + if (ret) > + goto err_reset; > + vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); > + } > + GEM_WARN_ON(vma == ERR_PTR(-ENOSPC)); Looks like this is being triggered in CI, I assume because the trylock could easily fail, due to contention? Is this expected for now? Do we keep the WARN and track it as a known issue? > } > if (IS_ERR(vma)) { > ret = PTR_ERR(vma); > -- > 2.34.1 >
On 17-12-2021 12:58, Matthew Auld wrote: > On Thu, 16 Dec 2021 at 14:28, Maarten Lankhorst > <maarten.lankhorst@linux.intel.com> wrote: >> Now that we cannot unbind kill the currently locked object directly > "unbind kill" > >> because we're removing short term pinning, we may have to unbind the >> object from gtt manually, using a i915_gem_evict_vm() call. >> >> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Maybe mention that this only in preparation for some future patches, > once the actual eviction is trylock and evict_for_vm can also handle > shared dma-resv? At this point in the series we shouldn't expect to > hit -ENOSPC, right? > >> --- >> drivers/gpu/drm/i915/gem/i915_gem_mman.c | 18 ++++++++++++++++-- >> 1 file changed, 16 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c >> index af81d6c3332a..00cd9642669a 100644 >> --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c >> @@ -358,8 +358,22 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) >> vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); >> } >> >> - /* The entire mappable GGTT is pinned? Unexpected! */ >> - GEM_BUG_ON(vma == ERR_PTR(-ENOSPC)); >> + /* >> + * The entire mappable GGTT is pinned? Unexpected! >> + * Try to evict the object we locked too, as normally we skip it >> + * due to lack of short term pinning inside execbuf. >> + */ >> + if (vma == ERR_PTR(-ENOSPC)) { >> + ret = mutex_lock_interruptible(&ggtt->vm.mutex); >> + if (!ret) { >> + ret = i915_gem_evict_vm(&ggtt->vm); >> + mutex_unlock(&ggtt->vm.mutex); >> + } >> + if (ret) >> + goto err_reset; >> + vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); >> + } >> + GEM_WARN_ON(vma == ERR_PTR(-ENOSPC)); > Looks like this is being triggered in CI, I assume because the trylock > could easily fail, due to contention? Is this expected for now? Do we > keep the WARN and track it as a known issue? I think it makes sense. I can probably fix i915_gem_evict_vm to attempt to take all objects in a blocking way. I had some primitives that could lock for eviction, and keep a refcount on the object. i915_gem_evict_vm could probably be changed to use it. >> } >> if (IS_ERR(vma)) { >> ret = PTR_ERR(vma); >> -- >> 2.34.1 >>
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index af81d6c3332a..00cd9642669a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -358,8 +358,22 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); } - /* The entire mappable GGTT is pinned? Unexpected! */ - GEM_BUG_ON(vma == ERR_PTR(-ENOSPC)); + /* + * The entire mappable GGTT is pinned? Unexpected! + * Try to evict the object we locked too, as normally we skip it + * due to lack of short term pinning inside execbuf. + */ + if (vma == ERR_PTR(-ENOSPC)) { + ret = mutex_lock_interruptible(&ggtt->vm.mutex); + if (!ret) { + ret = i915_gem_evict_vm(&ggtt->vm); + mutex_unlock(&ggtt->vm.mutex); + } + if (ret) + goto err_reset; + vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags); + } + GEM_WARN_ON(vma == ERR_PTR(-ENOSPC)); } if (IS_ERR(vma)) { ret = PTR_ERR(vma);
Now that we cannot unbind kill the currently locked object directly because we're removing short term pinning, we may have to unbind the object from gtt manually, using a i915_gem_evict_vm() call. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> --- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)