diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-07-31 09:50:12 +0100 |
|---|---|---|
| committer | Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2020-09-07 13:18:36 +0300 |
| commit | 99a7f4dae7ee6081df04741e0c4ea5e49b139540 (patch) | |
| tree | 2d16bacb5fec32fdaff5d1109cdd5d74d62620d8 /drivers/gpu/drm/i915/i915_active.c | |
| parent | 5d9341370f57c058a8d880490ba9e79e761b2d7a (diff) | |
drm/i915: Keep the most recently used active-fence upon discard
Whenever an i915_active idles, we prune its tree of old fence slots to
prevent a gradual leak should it be used to track many, many timelines.
The downside is that we then have to frequently reallocate the rbtree.
A compromise is that we keep the most recently used fence slot, and
reuse that for the next active reference as that is the most likely
timeline to be reused.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-4-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_active.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_active.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c index 9890db303fed..e63578c80f53 100644 --- a/drivers/gpu/drm/i915/i915_active.c +++ b/drivers/gpu/drm/i915/i915_active.c @@ -130,8 +130,8 @@ static inline void debug_active_assert(struct i915_active *ref) { } static void __active_retire(struct i915_active *ref) { + struct rb_root root = RB_ROOT; struct active_node *it, *n; - struct rb_root root; unsigned long flags; GEM_BUG_ON(i915_active_is_idle(ref)); @@ -143,9 +143,21 @@ __active_retire(struct i915_active *ref) GEM_BUG_ON(rcu_access_pointer(ref->excl.fence)); debug_active_deactivate(ref); - root = ref->tree; - ref->tree = RB_ROOT; - ref->cache = NULL; + /* Even if we have not used the cache, we may still have a barrier */ + if (!ref->cache) + ref->cache = fetch_node(ref->tree.rb_node); + + /* Keep the MRU cached node for reuse */ + if (ref->cache) { + /* Discard all other nodes in the tree */ + rb_erase(&ref->cache->node, &ref->tree); + root = ref->tree; + + /* Rebuild the tree with only the cached node */ + rb_link_node(&ref->cache->node, NULL, &ref->tree.rb_node); + rb_insert_color(&ref->cache->node, &ref->tree); + GEM_BUG_ON(ref->tree.rb_node != &ref->cache->node); + } spin_unlock_irqrestore(&ref->tree_lock, flags); @@ -156,6 +168,7 @@ __active_retire(struct i915_active *ref) /* ... except if you wait on it, you must manage your own references! */ wake_up_var(ref); + /* Finally free the discarded timeline tree */ rbtree_postorder_for_each_entry_safe(it, n, &root, node) { GEM_BUG_ON(i915_active_fence_isset(&it->base)); kmem_cache_free(global.slab_cache, it); @@ -745,16 +758,16 @@ int i915_sw_fence_await_active(struct i915_sw_fence *fence, return await_active(ref, flags, sw_await_fence, fence, fence); } -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) void i915_active_fini(struct i915_active *ref) { debug_active_fini(ref); GEM_BUG_ON(atomic_read(&ref->count)); GEM_BUG_ON(work_pending(&ref->work)); - GEM_BUG_ON(!RB_EMPTY_ROOT(&ref->tree)); mutex_destroy(&ref->mutex); + + if (ref->cache) + kmem_cache_free(global.slab_cache, ref->cache); } -#endif static inline bool is_idle_barrier(struct active_node *node, u64 idx) { |