| Message ID | 20221019230547.3590-1-vinay.belgaumkar@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/i915/slpc: Optmize waitboost for SLPC | expand |
On 10/19/2022 4:05 PM, Vinay Belgaumkar wrote: > 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 RP0 if GuC is already requesting the > same. > > v2: Add the tracing back, and check requested freq > in the worker thread (Tvrtko) > > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_rps.c | 3 +++ > drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 7 ++++++- > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c > index fc23c562d9b2..18b75cf08d1b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_rps.c > +++ b/drivers/gpu/drm/i915/gt/intel_rps.c > @@ -1016,6 +1016,9 @@ void intel_rps_boost(struct i915_request *rq) > if (rps_uses_slpc(rps)) { > slpc = rps_to_slpc(rps); > > + GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n", > + rq->fence.context, rq->fence.seqno); > + > /* Return if old value is non zero */ > if (!atomic_fetch_inc(&slpc->num_waiters)) The issue when we move the req freq check into the slpc_work is that we are incrementing num_waiters. That will trigger a de-boost and result in a H2G. Need to check the req frequency there as well. Thanks, Vinay. > schedule_work(&slpc->boost_work); > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c > index b7cdeec44bd3..7ab96221be7e 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c > @@ -227,14 +227,19 @@ static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq) > static void slpc_boost_work(struct work_struct *work) > { > struct intel_guc_slpc *slpc = container_of(work, typeof(*slpc), boost_work); > + struct intel_rps *rps = &slpc_to_gt(slpc)->rps; > int err; > > /* > * Raise min freq to boost. It's possible that > * this is greater than current max. But it will > * certainly be limited by RP0. An error setting > - * the min param is not fatal. > + * the min param is not fatal. No need to boost > + * if we are already requesting it. > */ > + if (intel_rps_get_requested_frequency(rps) == slpc->boost_freq) > + return; > + > mutex_lock(&slpc->lock); > if (atomic_read(&slpc->num_waiters)) { > err = slpc_force_min_freq(slpc, slpc->boost_freq);
diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c index fc23c562d9b2..18b75cf08d1b 100644 --- a/drivers/gpu/drm/i915/gt/intel_rps.c +++ b/drivers/gpu/drm/i915/gt/intel_rps.c @@ -1016,6 +1016,9 @@ void intel_rps_boost(struct i915_request *rq) if (rps_uses_slpc(rps)) { slpc = rps_to_slpc(rps); + GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n", + rq->fence.context, rq->fence.seqno); + /* Return if old value is non zero */ if (!atomic_fetch_inc(&slpc->num_waiters)) schedule_work(&slpc->boost_work); diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c index b7cdeec44bd3..7ab96221be7e 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c @@ -227,14 +227,19 @@ static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq) static void slpc_boost_work(struct work_struct *work) { struct intel_guc_slpc *slpc = container_of(work, typeof(*slpc), boost_work); + struct intel_rps *rps = &slpc_to_gt(slpc)->rps; int err; /* * Raise min freq to boost. It's possible that * this is greater than current max. But it will * certainly be limited by RP0. An error setting - * the min param is not fatal. + * the min param is not fatal. No need to boost + * if we are already requesting it. */ + if (intel_rps_get_requested_frequency(rps) == slpc->boost_freq) + return; + mutex_lock(&slpc->lock); if (atomic_read(&slpc->num_waiters)) { err = slpc_force_min_freq(slpc, slpc->boost_freq);
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 RP0 if GuC is already requesting the same. v2: Add the tracing back, and check requested freq in the worker thread (Tvrtko) Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com> --- drivers/gpu/drm/i915/gt/intel_rps.c | 3 +++ drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-)