[PATCH] drm/i915/shrinker: Refactor common uninterruptible locking

Chris Wilson
2016-04-05T09:22:34Z

Both the oom and vmap notifier callbacks have a loop to acquire the
struct_mutex and set the device as uninterruptible, within a certain
time. Refactor the common code into a pair of functions.

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>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
drivers/gpu/drm/i915/i915_gem_shrinker.c | 79 +++++++++++++++++---------------
1 file changed, 42 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index be7501afb59e..39943793edcc 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -289,35 +289,56 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
return freed;
}

+struct shrinker_lock_uninterruptible {
+ bool was_interruptible;
+ bool unlock;
+};
+
+static bool
+i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private *dev_priv,
+ struct shrinker_lock_uninterruptible *slu,
+ int timeout_ms)
+{
+ unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;
+
+ while (!i915_gem_shrinker_lock(dev_priv->dev, &slu->unlock)) {
+ schedule_timeout_killable(1);
+ if (fatal_signal_pending(current))
+ return false;
+ if (--timeout == 0) {
+ pr_err("Unable to lock GPU to purge memory.\n");
+ return false;
+ }
+ }
+
+ slu->was_interruptible = dev_priv->mm.interruptible;
+ dev_priv->mm.interruptible = false;
+ return true;
+}
+
+static void
+i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private *dev_priv,
+ struct shrinker_lock_uninterruptible *slu)
+{
+ dev_priv->mm.interruptible = slu->was_interruptible;
+ if (slu->unlock)
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+}
+
static int
i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
{
struct drm_i915_private *dev_priv =
container_of(nb, struct drm_i915_private, mm.oom_notifier);
- struct drm_device *dev = dev_priv->dev;
+ struct shrinker_lock_uninterruptible slu;
struct drm_i915_gem_object *obj;
- unsigned long timeout = msecs_to_jiffies(5000) + 1;
unsigned long pinned, bound, unbound, freed_pages;
- bool was_interruptible;
- bool unlock;

- while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
- schedule_timeout_killable(1);
- if (fatal_signal_pending(current))
- return NOTIFY_DONE;
- }
- if (timeout == 0) {
- pr_err("Unable to purge GPU memory due lock contention.\n");
+ if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
return NOTIFY_DONE;
- }
-
- was_interruptible = dev_priv->mm.interruptible;
- dev_priv->mm.interruptible = false;

freed_pages = i915_gem_shrink_all(dev_priv);

- dev_priv->mm.interruptible = was_interruptible;
-
/* Because we may be allocating inside our own driver, we cannot
* assert that there are no objects with pinned pages that are not
* being pointed to by hardware.
@@ -342,8 +363,7 @@ i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
bound += obj->base.size;
}

- if (unlock)
- mutex_unlock(&dev->struct_mutex);
+ i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);

if (freed_pages || unbound || bound)
pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
@@ -362,30 +382,15 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
{
struct drm_i915_private *dev_priv =
container_of(nb, struct drm_i915_private, mm.vmap_notifier);
- struct drm_device *dev = dev_priv->dev;
- unsigned long timeout = msecs_to_jiffies(5000) + 1;
+ struct shrinker_lock_uninterruptible slu;
unsigned long freed_pages;
- bool was_interruptible;
- bool unlock;

- while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
- schedule_timeout_killable(1);
- if (fatal_signal_pending(current))
- return NOTIFY_DONE;
- }
- if (timeout == 0) {
- pr_err("Unable to purge GPU vmaps due to lock contention.\n");
+ if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
return NOTIFY_DONE;
- }
-
- was_interruptible = dev_priv->mm.interruptible;
- dev_priv->mm.interruptible = false;

freed_pages = i915_gem_shrink_all(dev_priv);

- dev_priv->mm.interruptible = was_interruptible;
- if (unlock)
- mutex_unlock(&dev->struct_mutex);
+ i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);

*(unsigned long *)ptr += freed_pages;
return NOTIFY_DONE;
--
2.8.0.rc3