[PATCH -v3 01/10] locking/drm: Kill mutex trickery
From: Peter Zijlstra
Date: Mon Sep 05 2016 - 08:44:40 EST
Poking at lock internals is not cool. Since I'm going to change the
implementation this will break, take it out.
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_shrinker.c | 26 +++-----------------------
drivers/gpu/drm/msm/msm_gem_shrinker.c | 23 +++--------------------
2 files changed, 6 insertions(+), 43 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;
}
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -18,29 +18,12 @@
#include "msm_drv.h"
#include "msm_gem.h"
-static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
-{
- if (!mutex_is_locked(mutex))
- return false;
-
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
- return mutex->owner == task;
-#else
- /* Since UP may be pre-empted, we cannot assume that we own the lock */
- return false;
-#endif
-}
-
static bool msm_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;
- *unlock = false;
- } else {
- *unlock = true;
- }
+ if (!mutex_trylock(&dev->struct_mutex))
+ return false;
+ *unlock = true;
return true;
}