Quoting Tvrtko Ursulin (2018-07-19 12:18:26)
>
> On 19/07/2018 08:22, Chris Wilson wrote:
> > If we call into the shrinker for direct relcaim inside kmalloc, it will
> > retire the requests. If we retire the vma->last_active while a new
> > i915_vma_move_to_active() we can upset the delicate bookkeeping required
> > for the cache. After the possible invocation of the shrinker, we need to
> > double check the vma->last_active is still valid.
> >
> > Fixes: 8b293eb53a7d ("drm/i915: Track the last-active inside the i915_vma")
> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/i915_vma.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> > index ed4e0fb558f7..11d834f94220 100644
> > --- a/drivers/gpu/drm/i915/i915_vma.c
> > +++ b/drivers/gpu/drm/i915/i915_vma.c
> > @@ -942,6 +942,14 @@ static struct i915_gem_active *active_instance(struct i915_vma *vma, u64 idx)
> > }
> >
> > active = kmalloc(sizeof(*active), GFP_KERNEL);
> > +
> > + /* kmalloc may retire the vma->last_active request (thanks shrinker)! */
> > + if (unlikely(!i915_gem_active_raw(&vma->last_active,
> > + &vma->vm->i915->drm.struct_mutex))) {
> > + kfree(active);
> > + goto out;
> > + }
> > +
> > if (unlikely(!active))
> > return ERR_PTR(-ENOMEM);
> >
> >
>
> Fun!
>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Pushed to keep CI ticking over.
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
