diff options
author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 14:40:00 +0100 |
---|---|---|
committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 15:39:12 +0100 |
commit | b1e3177bd1d8f41e2a9cc847e56a96cdc0eefe62 (patch) | |
tree | 9af22565533f12868a015e18e51406d54773e08a /drivers/gpu/drm/i915/i915_active_types.h | |
parent | 274cbf20fd108fa26d0497282b102e00371210fd (diff) |
drm/i915: Coordinate i915_active with its own mutex
Forgo the struct_mutex serialisation for i915_active, and interpose its
own mutex handling for active/retire.
This is a multi-layered sleight-of-hand. First, we had to ensure that no
active/retire callbacks accidentally inverted the mutex ordering rules,
nor assumed that they were themselves serialised by struct_mutex. More
challenging though, is the rule over updating elements of the active
rbtree. Instead of the whole i915_active now being serialised by
struct_mutex, allocations/rotations of the tree are serialised by the
i915_active.mutex and individual nodes are serialised by the caller
using the i915_timeline.mutex (we need to use nested spinlocks to
interact with the dma_fence callback lists).
The pain point here is that instead of a single mutex around execbuf, we
now have to take a mutex for active tracker (one for each vma, context,
etc) and a couple of spinlocks for each fence update. The improvement in
fine grained locking allowing for multiple concurrent clients
(eventually!) should be worth it in typical loads.
v2: Add some comments that barely elucidate anything :(
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-6-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_active_types.h')
-rw-r--r-- | drivers/gpu/drm/i915/i915_active_types.h | 23 |
1 files changed, 6 insertions, 17 deletions
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h index 021167f0004d..d89a74c142c6 100644 --- a/drivers/gpu/drm/i915/i915_active_types.h +++ b/drivers/gpu/drm/i915/i915_active_types.h @@ -17,17 +17,9 @@ #include "i915_utils.h" -struct drm_i915_private; -struct i915_active_request; -struct i915_request; - -typedef void (*i915_active_retire_fn)(struct i915_active_request *, - struct i915_request *); - -struct i915_active_request { - struct i915_request __rcu *request; - struct list_head link; - i915_active_retire_fn retire; +struct i915_active_fence { + struct dma_fence __rcu *fence; + struct dma_fence_cb cb; #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) /* * Incorporeal! @@ -53,20 +45,17 @@ struct active_node; #define i915_active_may_sleep(fn) ptr_pack_bits(&(fn), I915_ACTIVE_MAY_SLEEP, 2) struct i915_active { - struct drm_i915_private *i915; + atomic_t count; + struct mutex mutex; struct active_node *cache; struct rb_root tree; - struct mutex mutex; - atomic_t count; /* Preallocated "exclusive" node */ - struct dma_fence __rcu *excl; - struct dma_fence_cb excl_cb; + struct i915_active_fence excl; unsigned long flags; #define I915_ACTIVE_RETIRE_SLEEPS BIT(0) -#define I915_ACTIVE_GRAB_BIT 1 int (*active)(struct i915_active *ref); void (*retire)(struct i915_active *ref); |