Messages in this thread | | | Date | Mon, 23 May 2022 16:53:26 +0100 | Subject | Re: [PATCH 3/4] drm/i915: allow volatile buffers to use ttm pool allocator | From | Robert Beckett <> |
| |
On 11/05/2022 13:42, Thomas Hellström wrote: > Hi, Bob, > > On Tue, 2022-05-03 at 19:13 +0000, Robert Beckett wrote: >> internal buffers should be shmem backed. >> if a volatile buffer is requested, allow ttm to use the pool >> allocator >> to provide volatile pages as backing >> >> Signed-off-by: Robert Beckett <bob.beckett@collabora.com> >> --- >> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> index 4c25d9b2f138..fdb3a1c18cb6 100644 >> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> @@ -309,7 +309,8 @@ static struct ttm_tt *i915_ttm_tt_create(struct >> ttm_buffer_object *bo, >> page_flags |= TTM_TT_FLAG_ZERO_ALLOC; >> >> caching = i915_ttm_select_tt_caching(obj); >> - if (i915_gem_object_is_shrinkable(obj) && caching == >> ttm_cached) { >> + if (i915_gem_object_is_shrinkable(obj) && caching == >> ttm_cached && >> + !i915_gem_object_is_volatile(obj)) { >> page_flags |= TTM_TT_FLAG_EXTERNAL | >> TTM_TT_FLAG_EXTERNAL_MAPPABLE; >> i915_tt->is_shmem = true; > > While this is ok, I think it also needs adjustment in the i915_ttm > shrink callback. If someone creates a volatile smem object which then > hits the shrinker, I think we might hit asserts that it's a is_shem > ttm? > > In this case, the shrink callback should just i915_ttm_purge().
agreed. nice catch. I'll fix for v2
looks like we could maybe do with some extra shrinker testing too? looks like nothing caught this during CI testing
> > /Thomas > >
| |