diff options
author | Chris Wilson <[email protected]> | 2017-05-17 13:10:05 +0100 |
---|---|---|
committer | Chris Wilson <[email protected]> | 2017-05-17 13:38:13 +0100 |
commit | 349bdb68bd48f4e1861058ac2dbaa0aafd4ca38d (patch) | |
tree | 47313c4d515f04daf17f46cb798cd1a8ba20d53c | |
parent | c5cf9a9147ff6fc9f87251a8f8a5b6ac8b8bdcdc (diff) |
drm/i915/execlists: Reduce lock contention between schedule/submit_request
If we do not require to perform priority bumping, and we haven't yet
submitted the request, we can update its priority in situ and skip
acquiring the engine locks -- thus avoiding any contention between us
and submit/execute.
v2: Remove the stack element from the list if we can do the early
assignment.
Signed-off-by: Chris Wilson <[email protected]>
Reviewed-by: Tvrtko Ursulin <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
-rw-r--r-- | drivers/gpu/drm/i915/intel_lrc.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 8529746dd7cc..014b30ace8a0 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -779,6 +779,19 @@ static void execlists_schedule(struct drm_i915_gem_request *request, int prio) list_safe_reset_next(dep, p, dfs_link); } + /* If we didn't need to bump any existing priorities, and we haven't + * yet submitted this request (i.e. there is no potential race with + * execlists_submit_request()), we can set our own priority and skip + * acquiring the engine locks. + */ + if (request->priotree.priority == INT_MIN) { + GEM_BUG_ON(!list_empty(&request->priotree.link)); + request->priotree.priority = prio; + if (stack.dfs_link.next == stack.dfs_link.prev) + return; + __list_del_entry(&stack.dfs_link); + } + engine = request->engine; spin_lock_irq(&engine->timeline->lock); |