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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-07-03 21:06:01 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-07-04 17:34:35 +0300 |
| commit | 0c159ffef628fa94d0f4f9128e7f2b6f2b5e86ef (patch) | |
| tree | b03539a32585baf353d26f051bef55c9de15899d /drivers/gpu/drm/i915/gem/i915_gem_object.c | |
| parent | 21de5a9e34fb0f3efa31df5712cedc0ae97f7b4d (diff) | |
| download | linux-0c159ffef628fa94d0f4f9128e7f2b6f2b5e86ef.tar.xz | |
drm/i915/gem: Defer obj->base.resv fini until RCU callback
Since reservation_object_fini() does an immediate free, rather than
kfree_rcu as normal, we have to delay the release until after the RCU
grace period has elapsed (i.e. from the rcu cleanup callback) so that we
can rely on the RCU protected access to the fences while the object is a
zombie.
i915_gem_busy_ioctl relies on having an RCU barrier to protect the
reservation in order to avoid having to take a reference and strong
memory barriers.
v2: Order is important; only release after putting the pages!
Fixes: c03467ba40f7 ("drm/i915/gem: Free pages before rcu-freeing the object")
Testcase: igt/gem_busy/close-race
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190703180601.10950-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_object.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_object.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c index d3e96f09c6b7..d5197a2a106f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c @@ -152,6 +152,7 @@ static void __i915_gem_free_object_rcu(struct rcu_head *head) container_of(head, typeof(*obj), rcu); struct drm_i915_private *i915 = to_i915(obj->base.dev); + reservation_object_fini(&obj->base._resv); i915_gem_object_free(obj); GEM_BUG_ON(!atomic_read(&i915->mm.free_count)); @@ -187,9 +188,6 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915, GEM_BUG_ON(atomic_read(&obj->frontbuffer_bits)); GEM_BUG_ON(!list_empty(&obj->lut_list)); - if (obj->ops->release) - obj->ops->release(obj); - atomic_set(&obj->mm.pages_pin_count, 0); __i915_gem_object_put_pages(obj, I915_MM_NORMAL); GEM_BUG_ON(i915_gem_object_has_pages(obj)); @@ -198,7 +196,10 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915, if (obj->base.import_attach) drm_prime_gem_destroy(&obj->base, NULL); - drm_gem_object_release(&obj->base); + drm_gem_free_mmap_offset(&obj->base); + + if (obj->ops->release) + obj->ops->release(obj); /* But keep the pointer alive for RCU-protected lookups */ call_rcu(&obj->rcu, __i915_gem_free_object_rcu); |