1. 17 5月, 2019 2 次提交
    • C
      drm/i915: Truly bump ready tasks ahead of busywaits · 17db337f
      Chris Wilson 提交于
      In commit b7404c7e ("drm/i915: Bump ready tasks ahead of
      busywaits"), I tried cutting a corner in order to not install a signal
      for each of our dependencies, and only listened to requests on which we
      were intending to busywait. The compromise that was made was that
      instead of then being able to promote the request with a full
      NOSEMAPHORE like its non-busywaiting brethren, as we had not ensured we
      had cleared the semaphore chain, we settled for only using the NEWCLIENT
      boost. With an over saturated system with multiple NEWCLIENTS in flight
      at any time, this was found to be an inadequate promotion and left us
      with a much poorer scheduling order than prior to using semaphores.
      
      The outcome of this patch, is that all requests have NOSEMAPHORE
      priority when they have no dependencies and are ready to run and not
      busywait, restoring the pre-semaphore ordering on saturated systems.
      
      We can demonstrate the effect of poor scheduling order by oversaturating
      the system using gem_wsim on a system with multiple vcs engines
      (i.e running the same workloads across more clients than required for
      peak throughput, e.g. media_load_balance_17i7.wsim -c4 -b context):
      
      x v5.1 (normalized)
      + tip
      * fix
      +------------------------------------------------------------------------+
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      +------------------------------------------------------------------------+
          N           Min           Max        Median           Avg        Stddev
      x 120       0.99456       1.00628      0.999985     1.0001545  0.0024387139
      + 120      0.873021       1.00037      0.884134    0.90148752   0.039190862
      Difference at 99.5% confidence
      	-0.098667 +/- 0.0110762
      	-9.86517% +/- 1.10745%
      	(Student's t, pooled s = 0.0277657)
      % 120      0.990207       1.00165     0.9970265    0.99699748     0.0021024
      Difference at 99.5% confidence
      	-0.003157 +/- 0.000908245
      	-0.315651% +/- 0.0908105%
      	(Student's t, pooled s = 0.00227678)
      
      Fixes: b7404c7e ("drm/i915: Bump ready tasks ahead of busywaits")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
      Cc: Dmitry Ermilov <dmitry.ermilov@intel.com>
      Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20190515130052.4475-2-chris@chris-wilson.co.uk
      17db337f
    • C
      drm/i915: Mark semaphores as complete on unsubmit out if payload was started · dba5a7f3
      Chris Wilson 提交于
      Avoid charging us for the presumed busywait if the request was preempted
      after successfully using semaphores to reduce inter-engine latency.
      
      v2: Bump the priority to reflect the lack of semaphores now required.
      
      References: ca6e56f6 ("drm/i915: Disable semaphore busywaits on saturated systems")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20190515130052.4475-1-chris@chris-wilson.co.uk
      dba5a7f3
  2. 14 5月, 2019 17 次提交
  3. 13 5月, 2019 3 次提交
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  5. 08 5月, 2019 9 次提交