| Message ID | aa55eef7e63b8f3d0f69b525db2dd2eb87e9db6b.1658924372.git.mchehab@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: reduce TLB performance regressions | expand |
Hi Mauro, > TLB cache invalidation can happen on two different situations: > > 1. synchronously, at __vma_put_pages(); > 2. asynchronously. > > On the first case, TLB cache invalidation happens inside > __vma_put_pages(). So, no need to do it later on. > > However, on the second case, the pages will keep in memory > until __i915_vma_evict() is called. > > So, we need to store the TLB data at struct i915_vma_resource, > in order to do a TLB cache invalidation before allowing > userspace to re-use the same memory. > > So, i915_vma_resource_unbind() has gained a new parameter > in order to store the TLB data at the second case. > > Document it. > > Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> > --- > > To avoid mailbombing on a large number of people, only mailing lists were C/C on the cover. > See [PATCH v3 0/6] at: https://lore.kernel.org/all/cover.1658924372.git.mchehab@kernel.org/ > > drivers/gpu/drm/i915/i915_vma_resource.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_vma_resource.c b/drivers/gpu/drm/i915/i915_vma_resource.c > index 5a67995ea5fe..4fe09ea0a825 100644 > --- a/drivers/gpu/drm/i915/i915_vma_resource.c > +++ b/drivers/gpu/drm/i915/i915_vma_resource.c > @@ -216,6 +216,10 @@ i915_vma_resource_fence_notify(struct i915_sw_fence *fence, > /** > * i915_vma_resource_unbind - Unbind a vma resource > * @vma_res: The vma resource to unbind. > + * @tlb: pointer to vma->obj->mm.tlb associated with the resource > + * to be stored at vma_res->tlb. When not-NULL, it will be used > + * to do TLB cache invalidation before freeing a VMA resource. > + * used only for async unbind. /used/Used/ With that: Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Thanks, Andi
diff --git a/drivers/gpu/drm/i915/i915_vma_resource.c b/drivers/gpu/drm/i915/i915_vma_resource.c index 5a67995ea5fe..4fe09ea0a825 100644 --- a/drivers/gpu/drm/i915/i915_vma_resource.c +++ b/drivers/gpu/drm/i915/i915_vma_resource.c @@ -216,6 +216,10 @@ i915_vma_resource_fence_notify(struct i915_sw_fence *fence, /** * i915_vma_resource_unbind - Unbind a vma resource * @vma_res: The vma resource to unbind. + * @tlb: pointer to vma->obj->mm.tlb associated with the resource + * to be stored at vma_res->tlb. When not-NULL, it will be used + * to do TLB cache invalidation before freeing a VMA resource. + * used only for async unbind. * * At this point this function does little more than publish a fence that * signals immediately unless signaling is held back.
TLB cache invalidation can happen on two different situations: 1. synchronously, at __vma_put_pages(); 2. asynchronously. On the first case, TLB cache invalidation happens inside __vma_put_pages(). So, no need to do it later on. However, on the second case, the pages will keep in memory until __i915_vma_evict() is called. So, we need to store the TLB data at struct i915_vma_resource, in order to do a TLB cache invalidation before allowing userspace to re-use the same memory. So, i915_vma_resource_unbind() has gained a new parameter in order to store the TLB data at the second case. Document it. Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> --- To avoid mailbombing on a large number of people, only mailing lists were C/C on the cover. See [PATCH v3 0/6] at: https://lore.kernel.org/all/cover.1658924372.git.mchehab@kernel.org/ drivers/gpu/drm/i915/i915_vma_resource.c | 4 ++++ 1 file changed, 4 insertions(+)