diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-11-03 16:23:05 +0000 |
|---|---|---|
| committer | Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2019-11-05 09:56:03 +0200 |
| commit | 8eb4704b124cbd44f189709959137d77063ecfa1 (patch) | |
| tree | 609ccf8b5d80699cab78194934bd6c2c699db07d | |
| parent | 8a86b00a437ec06b298477463c7a9b8774570507 (diff) | |
drm/i915: Protect request peeking with RCU
Since the execlists_active() is no longer protected by the
engine->active.lock, we need to protect the request pointer with RCU to
prevent it being freed as we evaluate whether or not we need to preempt.
Fixes: df403069029d ("drm/i915/execlists: Lift process_csb() out of the irq-off spinlock")
Fixes: 13ed13a4dcbf ("drm/i915: Don't set queue_priority_hint if we don't kick the submission")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191104090158.2959-2-chris@chris-wilson.co.uk
(cherry picked from commit 7d148635253328dda7cfe55d57e3c828e9564427)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_scheduler.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index d2edb527dcb8..010d67f48ad9 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -202,21 +202,26 @@ static void kick_submission(struct intel_engine_cs *engine, if (prio <= engine->execlists.queue_priority_hint) return; + rcu_read_lock(); + /* Nothing currently active? We're overdue for a submission! */ inflight = execlists_active(&engine->execlists); if (!inflight) - return; + goto unlock; /* * If we are already the currently executing context, don't * bother evaluating if we should preempt ourselves. */ if (inflight->hw_context == rq->hw_context) - return; + goto unlock; engine->execlists.queue_priority_hint = prio; if (need_preempt(prio, rq_prio(inflight))) tasklet_hi_schedule(&engine->execlists.tasklet); + +unlock: + rcu_read_unlock(); } static void __i915_schedule(struct i915_sched_node *node, |