Commit f864a29a authored by Vinay Belgaumkar's avatar Vinay Belgaumkar Committed by John Harrison
Browse files

drm/i915/slpc: Optmize waitboost for SLPC 



Waitboost (when SLPC is enabled) results in a H2G message. This can result
in thousands of messages during a stress test and fill up an already full
CTB. There is no need to request for boost if min softlimit is equal or
greater than it.

v2: Add the tracing back, and check requested freq
in the worker thread (Tvrtko)
v3: Check requested freq in dec_waiters as well
v4: Only check min_softlimit against boost_freq. Limit this
optimization for server parts for now.
v5: min_softlimit can be greater than boost (Ashutosh)

Reviewed-by: default avatarAshutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: default avatarVinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221024171108.14373-1-vinay.belgaumkar@intel.com
parent e62f31e1

drivers/gpu/drm/i915/gt/intel_rps.c

+7 −1
Original line number Diff line number Diff line
@@ -1014,9 +1014,15 @@ void intel_rps_boost(struct i915_request *rq) 
		if (rps_uses_slpc(rps)) {

			slpc = rps_to_slpc(rps);



			if (slpc->min_freq_softlimit >= slpc->boost_freq)

				return;



			/* Return if old value is non zero */

			if (!atomic_fetch_inc(&slpc->num_waiters))

			if (!atomic_fetch_inc(&slpc->num_waiters)) {

				GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n",

					 rq->fence.context, rq->fence.seqno);

				schedule_work(&slpc->boost_work);

			}



			return;

		}