>-----Original Message----- >From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of >Matthew Auld >Sent: Wednesday, January 20, 2021 12:46 PM >To: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >Cc: Intel Graphics Development <intel-gfx@xxxxxxxxxxxxxxxxxxxxx>; Auld, >Matthew <matthew.auld@xxxxxxxxx> >Subject: Re: [PATCH] drm/i915/gem: Allow importing of shmemfs >objects into any device > >On Wed, 20 Jan 2021 at 15:40, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: >> >> If we import a shmemfs object between devices, for example from >> Tigerlake to DG1, we can simply reuse the native object and its backing >> store. > >Hmmm interesting, so does that include re-using the actual sg mapping >for the backing pages? Does that work out-of-the-box between different >devices assuming we have iommu enabled? > >> >> Suggested-by: Imre Deak <imre.deak@xxxxxxxxx> >> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> Cc: Matthew Auld <matthew.auld@xxxxxxxxx> >> Cc: Imre Deak <imre.deak@xxxxxxxxx> >> --- >> drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c >b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c >> index 04e9c04545ad..4816f08c4009 100644 >> --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c >> @@ -242,6 +242,13 @@ struct drm_gem_object >*i915_gem_prime_import(struct drm_device *dev, >> */ >> return &i915_gem_object_get(obj)->base; >> } >> + >> + /* >> + * If the object is in plain system memory, we can reuse the >> + * same backing store in any device. >> + */ >> + if (i915_gem_object_is_shmem(obj)) >> + return &i915_gem_object_get(obj)->base; >> } So this would mean sharing all of the object attributes between devices (pin count, etc)? I.e. vma list etc? Would that work? Mike >> /* need to attach */ >> -- >> 2.20.1 >> >> _______________________________________________ >> Intel-gfx mailing list >> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx >_______________________________________________ >Intel-gfx mailing list >Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx