openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

drm/i915: Disable tasklet scheduling across initial scheduling 

During request submission, we call the engine->schedule() function so
that we may reorder the active requests as required for inheriting the
new request's priority. This may schedule several tasklets to run on the
local CPU, but we will need to schedule the tasklets again for the new
request. Delay all the local tasklets until the end, so that we only
have to process the queue just once.

v2: Beware PREEMPT_RCU, as then local_bh_disable() is then not a
superset of rcu_read_lock().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180507135731.10587-2-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
This commit is contained in:
Chris Wilson 2018-05-07 14:57:26 +01:00
parent 4f6d8fcf1a
commit 71ace7ca25
1 changed files with 2 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/gpu/drm/i915/i915_request.c
View File

@ -1110,12 +1110,11 @@ void __i915_request_add(struct i915_request *request, bool flush_caches)
* decide whether to preempt the entire chain so that it is ready to * decide whether to preempt the entire chain so that it is ready to
* run at the earliest possible convenience. * run at the earliest possible convenience.
*/ */
rcu_read_lock(); local_bh_disable();
rcu_read_lock(); /* RCU serialisation for set-wedged protection */
if (engine->schedule) if (engine->schedule)
engine->schedule(request, &request->ctx->sched); engine->schedule(request, &request->ctx->sched);
rcu_read_unlock(); rcu_read_unlock();
local_bh_disable();
i915_sw_fence_commit(&request->submit); i915_sw_fence_commit(&request->submit);
local_bh_enable(); /* Kick the execlists tasklet if just scheduled */ local_bh_enable(); /* Kick the execlists tasklet if just scheduled */