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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-05-24 17:26:53 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-05-30 11:46:23 +0100 |
| commit | 00c26cf9ce4eadf3680e431a374eb4cdc6e824cd (patch) | |
| tree | 69c16d4813bee1b3deac1e03b629a3126bcd2aeb | |
| parent | b5a824250e4aac4fb76c5076b6a5e460e52c831a (diff) | |
| download | lwn-00c26cf9ce4eadf3680e431a374eb4cdc6e824cd.tar.gz lwn-00c26cf9ce4eadf3680e431a374eb4cdc6e824cd.zip | |
drm/i915: Remove toplevel struct_mutex locking from debugfs/i915_drop_caches
I have a plan to write a quick test to exercise concurrent usage of
i915_gem_shrink(), the simplest way looks to be to have multiple threads
using debugfs/i915_drop_caches. However, we currently take one lock over
the entire function, serialising the calls into i915_gem_shrink() so
reduce the lock coverage.
Testcase: igt/gem_shrink/reclaim
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/20170524162653.5446-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_debugfs.c | 30 |
1 files changed, 14 insertions, 16 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 7e0816ccdc21..3b088685a553 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4289,26 +4289,27 @@ i915_drop_caches_set(void *data, u64 val) { struct drm_i915_private *dev_priv = data; struct drm_device *dev = &dev_priv->drm; - int ret; + int ret = 0; DRM_DEBUG("Dropping caches: 0x%08llx\n", val); /* No need to check and wait for gpu resets, only libdrm auto-restarts * on ioctls on -EAGAIN. */ - ret = mutex_lock_interruptible(&dev->struct_mutex); - if (ret) - return ret; - - if (val & DROP_ACTIVE) { - ret = i915_gem_wait_for_idle(dev_priv, - I915_WAIT_INTERRUPTIBLE | - I915_WAIT_LOCKED); + if (val & (DROP_ACTIVE | DROP_RETIRE)) { + ret = mutex_lock_interruptible(&dev->struct_mutex); if (ret) - goto unlock; - } + return ret; - if (val & DROP_RETIRE) - i915_gem_retire_requests(dev_priv); + if (val & DROP_ACTIVE) + ret = i915_gem_wait_for_idle(dev_priv, + I915_WAIT_INTERRUPTIBLE | + I915_WAIT_LOCKED); + + if (val & DROP_RETIRE) + i915_gem_retire_requests(dev_priv); + + mutex_unlock(&dev->struct_mutex); + } lockdep_set_current_reclaim_state(GFP_KERNEL); if (val & DROP_BOUND) @@ -4321,9 +4322,6 @@ i915_drop_caches_set(void *data, u64 val) i915_gem_shrink_all(dev_priv); lockdep_clear_current_reclaim_state(); -unlock: - mutex_unlock(&dev->struct_mutex); - if (val & DROP_FREED) { synchronize_rcu(); i915_gem_drain_freed_objects(dev_priv); |