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author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-11-01 12:11:34 +0000 |
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committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-11-01 13:01:44 +0000 |
commit | 548625ee8fde571c32e7976879854410689c4a84 (patch) | |
tree | f11298515ad3856c48405452163adecd88fd17f5 /drivers/gpu/drm/i915/i915_gem_shrinker.c | |
parent | db6c2b4151f2915fe1695cdcac43b32e73d1ad32 (diff) | |
download | op-kernel-dev-548625ee8fde571c32e7976879854410689c4a84.zip op-kernel-dev-548625ee8fde571c32e7976879854410689c4a84.tar.gz |
drm/i915: Improve lockdep tracking for obj->mm.lock
The shrinker may appear to recurse into obj->mm.lock as the shrinker may
be called from a direct reclaim path whilst handling get_pages. We
filter out recursing on the same obj->mm.lock by inspecting
obj->mm.pages, but we do want to take the lock on a second object in
order to reap their pages. lockdep spots the recursion on the same
lockclass and needs annotation to avoid a false positive. To keep the
two paths distinct, create an enum to indicate which subclass of
obj->mm.lock we are using. This removes the false positive and avoids
masking real bugs.
Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161101121134.27504-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_shrinker.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_gem_shrinker.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c index 0993afc..f988652 100644 --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c @@ -111,7 +111,7 @@ static bool can_release_pages(struct drm_i915_gem_object *obj) static bool unsafe_drop_pages(struct drm_i915_gem_object *obj) { if (i915_gem_object_unbind(obj) == 0) - __i915_gem_object_put_pages(obj); + __i915_gem_object_put_pages(obj, I915_MM_SHRINKER); return !READ_ONCE(obj->mm.pages); } @@ -225,7 +225,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, if (unsafe_drop_pages(obj)) { /* May arrive from get_pages on another bo */ mutex_lock_nested(&obj->mm.lock, - SINGLE_DEPTH_NESTING); + I915_MM_SHRINKER); if (!obj->mm.pages) { __i915_gem_object_invalidate(obj); list_del_init(&obj->global_list); |