Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1470333

[RFC][PATCH -v2 1/4] locking/drm/i915: Kill mutex trickery

Show all headers | View raw

Poking at lock internals is not cool. Since I'm going to change the
implementation this will break, take it out.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/gpu/drm/i915/i915_gem_shrinker.c |   26 +++-----------------------
 1 file changed, 3 insertions(+), 23 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -35,19 +35,6 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 
-static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
-{
-	if (!mutex_is_locked(mutex))
-		return false;
-
-#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_MUTEX_SPIN_ON_OWNER)
-	return mutex->owner == task;
-#else
-	/* Since UP may be pre-empted, we cannot assume that we own the lock */
-	return false;
-#endif
-}
-
 static int num_vma_bound(struct drm_i915_gem_object *obj)
 {
 	struct i915_vma *vma;
@@ -238,17 +225,10 @@ unsigned long i915_gem_shrink_all(struct
 
 static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock)
 {
-	if (!mutex_trylock(&dev->struct_mutex)) {
-		if (!mutex_is_locked_by(&dev->struct_mutex, current))
-			return false;
-
-		if (to_i915(dev)->mm.shrinker_no_lock_stealing)
-			return false;
-
-		*unlock = false;
-	} else
-		*unlock = true;
+	if (!mutex_trylock(&dev->struct_mutex))
+		return false;
 
+	*unlock = true;
 	return true;
 }
 

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[RFC][PATCH -v2 1/4] locking/drm/i915: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-08-25 20:50 +0200
  Re: [RFC][PATCH -v2 1/4] locking/drm/i915: Kill mutex trickery Daniel Vetter <daniel.vetter@ffwll.ch> - 2016-08-25 21:40 +0200

csiph-web