[Intel-gfx] [PATCH v2] drm/i915: Priority boost for new clients

Wed Aug 8 19:24:15 UTC 2018

Quoting Chris Wilson (2018-08-08 19:53:33)
> Quoting Tvrtko Ursulin (2018-08-08 13:40:41)
> > 
> > On 07/08/2018 16:02, Chris Wilson wrote:
> > > Quoting Tvrtko Ursulin (2018-08-07 10:08:28)
> > >>
> > >> On 07/08/2018 08:29, Chris Wilson wrote:
> > >>> +     /*
> > >>> +      * The active request is now effectively the start of a new client
> > >>> +      * stream, so give it the equivalent small priority bump to prevent
> > >>> +      * it being gazumped a second time by another peer.
> > >>> +      */
> > >>> +     if (!(prio & I915_PRIORITY_NEWCLIENT)) {
> > >>> +             list_move_tail(&active->sched.link,
> > >>> +                            lookup_priolist(engine,
> > >>> +                                            prio | I915_PRIORITY_NEWCLIENT));
> > >>>        }
> > >>>    }
> > >>>    
> > >>>
> > >>
> > >> This sounds fair, I think I'm okay with it. Does it still work well for
> > >> mixed media workloads?
> > > 
> > > Grr. Current drm-tip is scoring much much higher in fairness than I
> > > remember, and there's no apparent improvement, even little room for
> > > possible improvement. When in doubt, blame ksoftirqd ;)
> > 
> > Perhaps previous testing was before direct submission?
> 
> I went back and checked that, unfortunately not that simple. The
> influencing factor appears to be the choice of workload. I am seeing
> some now that respond favourably (by pure chance selection) but I need
> to spend more time to ensure the results are stable, and see if there's
> any method to the madness in selection.

Early figures, suffering a bit from lack of transparency in the results.
(Using a pinned kbl gt4e)

TLDR;
w/o boosts:    busy balancer ('-b busy -R'): Aggregate (normalized) 89.28%; fairness 79.64%
w/  boosts:    busy balancer ('-b busy -R'): Aggregate (normalized) 108.92%; fairness 64.72%

Fairness went down (grumble) but that's a large increase in the
multiw-sim throughput.

Before:
ickle at kabylake:~/intel-gpu-tools$ sudo ./scripts/media-bench.pl -n 306765 -B busy -m -W media_nn_1080p_s1.wsim,media_nn_1080p_s2.wsim,media_nn_1080p_s3.wsim,media_nn_1080p.wsim,media_nn_480p.wsim
Workloads:
  media_nn_1080p_s1.wsim
  media_nn_1080p_s2.wsim
  media_nn_1080p_s3.wsim
  media_nn_1080p.wsim
  media_nn_480p.wsim
Balancers: busy,
Target workload duration is 10s.
Calibration tolerance is 0.01.
Multi-workload mode.
Nop calibration is 306765.

Evaluating 'media_nn_1080p_s1.wsim'... 10s is 177 workloads. (error=0.000300000000000011)
  Finding saturation points for 'media_nn_1080p_s1.wsim'...
    busy balancer ('-b busy -R'): 4 clients (31.844 wps, 17.671 wps single client, score=49.515).
    busy balancer ('-b busy -R -G'): 4 clients (31.957 wps, 17.667 wps single client, score=49.624).
    busy balancer ('-b busy -R -d'): 3 clients (31.904 wps, 17.677 wps single client, score=49.581).
    busy balancer ('-b busy -R -G -d'): 3 clients (32.046 wps, 17.624 wps single client, score=49.67).

Evaluating 'media_nn_1080p_s2.wsim'... 10s is 183 workloads. (error=0.00609999999999999)
  Finding saturation points for 'media_nn_1080p_s2.wsim'...
    busy balancer ('-b busy -R'): 3 clients (31.984 wps, 18.147 wps single client, score=50.131).
    busy balancer ('-b busy -R -G'): 3 clients (31.929 wps, 18.058 wps single client, score=49.987).
    busy balancer ('-b busy -R -d'): 2 clients (32.061 wps, 18.160 wps single client, score=50.221).
    busy balancer ('-b busy -R -G -d'): 3 clients (31.909 wps, 18.059 wps single client, score=49.968).

Evaluating 'media_nn_1080p_s3.wsim'... 10s is 182 workloads. (error=0.00719999999999992)
  Finding saturation points for 'media_nn_1080p_s3.wsim'...
    busy balancer ('-b busy -R'): 3 clients (31.957 wps, 18.044 wps single client, score=50.001).
    busy balancer ('-b busy -R -G'): 3 clients (31.930 wps, 18.134 wps single client, score=50.064).
    busy balancer ('-b busy -R -d'): 2 clients (32.047 wps, 18.054 wps single client, score=50.101).
    busy balancer ('-b busy -R -G -d'): 2 clients (31.972 wps, 18.040 wps single client, score=50.012).

Evaluating 'media_nn_1080p.wsim'... 10s is 156 workloads. (error=0.00470000000000006)
  Finding saturation points for 'media_nn_1080p.wsim'...
    busy balancer ('-b busy -R'): 4 clients (31.957 wps, 15.667 wps single client, score=47.624).
    busy balancer ('-b busy -R -G'): 4 clients (32.066 wps, 15.684 wps single client, score=47.75).
    busy balancer ('-b busy -R -d'): 5 clients (32.022 wps, 15.886 wps single client, score=47.908).
    busy balancer ('-b busy -R -G -d'): 4 clients (31.939 wps, 15.657 wps single client, score=47.596).

Evaluating 'media_nn_480p.wsim'... 10s is 337 workloads. (error=0.00820000000000007)
  Finding saturation points for 'media_nn_480p.wsim'...
    busy balancer ('-b busy -R'): 5 clients (74.077 wps, 33.412 wps single client, score=107.489).
    busy balancer ('-b busy -R -G'): 4 clients (73.849 wps, 33.415 wps single client, score=107.264).
    busy balancer ('-b busy -R -d'): 5 clients (73.357 wps, 33.319 wps single client, score=106.676).
    busy balancer ('-b busy -R -G -d'): 5 clients (73.540 wps, 33.497 wps single client, score=107.037).

Evaluating '-w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s1.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s2.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s3.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_480p.wsim'... 10s is 72 workloads. (error=0.00109999999999992)
  Finding saturation points for '-w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s1.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s2.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s3.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_480p.wsim'...
    busy balancer ('-b busy -R'): Aggregate (normalized) 89.28%; fairness 79.64%
    busy balancer ('-b busy -R -G'): Aggregate (normalized) 89.42%; fairness 79.52%
    busy balancer ('-b busy -R -d'): Aggregate (normalized) 89.60%; fairness 79.36%
    busy balancer ('-b busy -R -G -d'): Aggregate (normalized) 89.92%; fairness 79.15%
  Best balancer is '-b busy -R -G -d' (range=0.000886735101758962).

After:
ickle at kabylake:~/intel-gpu-tools$ sudo ./scripts/media-bench.pl -n 306765 -B busy -m -W media_nn_1080p_s1.wsim,media_nn_1080p_s2.wsim,media_nn_1080p_s3.wsim,media_nn_1080p.wsim,media_nn_480p.wsim
Workloads:
  media_nn_1080p_s1.wsim
  media_nn_1080p_s2.wsim
  media_nn_1080p_s3.wsim
  media_nn_1080p.wsim
  media_nn_480p.wsim
Balancers: busy,
Target workload duration is 10s.
Calibration tolerance is 0.01.
Multi-workload mode.
Nop calibration is 306765.

Evaluating 'media_nn_1080p_s1.wsim'... 10s is 177 workloads. (error=0.00180000000000007)
  Finding saturation points for 'media_nn_1080p_s1.wsim'...
    busy balancer ('-b busy -R'): 3 clients (31.846 wps, 17.674 wps single client, score=49.52).
    busy balancer ('-b busy -R -G'): 3 clients (31.929 wps, 17.668 wps single client, score=49.597).
    busy balancer ('-b busy -R -d'): 3 clients (31.874 wps, 17.620 wps single client, score=49.494).
    busy balancer ('-b busy -R -G -d'): 3 clients (31.888 wps, 17.676 wps single client, score=49.564).

Evaluating 'media_nn_1080p_s2.wsim'... 10s is 181 workloads. (error=0.000799999999999912)
  Finding saturation points for 'media_nn_1080p_s2.wsim'...
    busy balancer ('-b busy -R'): 3 clients (31.987 wps, 18.063 wps single client, score=50.05).
    busy balancer ('-b busy -R -G'): 3 clients (31.938 wps, 18.082 wps single client, score=50.02).
    busy balancer ('-b busy -R -d'): 3 clients (31.925 wps, 18.060 wps single client, score=49.985).
    busy balancer ('-b busy -R -G -d'): 2 clients (32.002 wps, 18.087 wps single client, score=50.089).

Evaluating 'media_nn_1080p_s3.wsim'... 10s is 182 workloads. (error=0.00779999999999994)
  Finding saturation points for 'media_nn_1080p_s3.wsim'...
    busy balancer ('-b busy -R'): 3 clients (32.005 wps, 18.042 wps single client, score=50.047).
    busy balancer ('-b busy -R -G'): 3 clients (32.013 wps, 18.156 wps single client, score=50.169).
    busy balancer ('-b busy -R -d'): 3 clients (32.090 wps, 18.079 wps single client, score=50.169).
    busy balancer ('-b busy -R -G -d'): 2 clients (32.094 wps, 18.038 wps single client, score=50.132).

Evaluating 'media_nn_1080p.wsim'... 10s is 156 workloads. (error=0.00459999999999994)
  Finding saturation points for 'media_nn_1080p.wsim'...
    busy balancer ('-b busy -R'): 5 clients (32.010 wps, 15.668 wps single client, score=47.678).
    busy balancer ('-b busy -R -G'): 4 clients (31.922 wps, 15.732 wps single client, score=47.654).
    busy balancer ('-b busy -R -d'): 3 clients (32.003 wps, 15.634 wps single client, score=47.637).
    busy balancer ('-b busy -R -G -d'): 4 clients (31.798 wps, 15.634 wps single client, score=47.432).

Evaluating 'media_nn_480p.wsim'... 10s is 336 workloads. (error=0.00510000000000002)
  Finding saturation points for 'media_nn_480p.wsim'...
    busy balancer ('-b busy -R'): 5 clients (73.326 wps, 33.979 wps single client, score=107.305).
    busy balancer ('-b busy -R -G'): 5 clients (73.588 wps, 33.410 wps single client, score=106.998).
    busy balancer ('-b busy -R -d'): 5 clients (73.734 wps, 33.280 wps single client, score=107.014).
    busy balancer ('-b busy -R -G -d'): 4 clients (73.139 wps, 33.768 wps single client, score=106.907).

Evaluating '-w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s1.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s2.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s3.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_480p.wsim'... 10s is 61 workloads. (error=0.00779999999999994)
  Finding saturation points for '-w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s1.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s2.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p_s3.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_1080p.wsim -w /home/ickle/intel-gpu-tools/benchmarks/wsim/media_nn_480p.wsim'...
    busy balancer ('-b busy -R'): Aggregate (normalized) 108.92%; fairness 64.72%
    busy balancer ('-b busy -R -G'): Aggregate (normalized) 109.23%; fairness 64.02%
    busy balancer ('-b busy -R -d'): Aggregate (normalized) 110.08%; fairness 55.50%
    busy balancer ('-b busy -R -G -d'): Aggregate (normalized) 108.42%; fairness 55.71%
  Best balancer is '-b busy -R' (range=0.0547794021204777).
-Chris