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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-05-07 16:23:38 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-05-07 20:08:58 +0100 |
| commit | eec39e441c29dd636bbdf5390af765cd9db6b380 (patch) | |
| tree | baa4f09e885695ae81109880b4e7e02025eb62f7 /drivers/gpu/drm/i915/gt | |
| parent | 6b6cd2ebd8d071e55998e32b648bb8081f7f02bb (diff) | |
| download | linux-eec39e441c29dd636bbdf5390af765cd9db6b380.tar.bz2 | |
drm/i915: Remove wait priority boosting
Upon waiting a request (when asked), we gave that request a small
priority boost, not enough for it to cause preemption, but enough for it
to be scheduled next before all equals. We also used that bit to give
new clients a small priority boost, similar to FQ_CODEL, such that we
favoured short interactive tasks ahead of long running streams.
However, this is causing lots of complications with timeslicing where we
both want to honour the boost and yet ignore it. Those complications
cause unexpected user behaviour (tasks not being timesliced and run
concurrently as epxected), and the easiest way to resolve that is to
remove the boost. Hopefully, we can find a compromise again if we need
to, but in theory timeslicing itself and future more advanced schedulers
should give us the interactivity boost we seek.
Testcase: igt/gem_exec_schedule/lateslice
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507152338.7452-3-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_lrc.c | 4 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 2 |
2 files changed, 2 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index dd0fd4c4cf32..59c99e2f0257 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -438,9 +438,7 @@ static int effective_prio(const struct i915_request *rq) if (__i915_request_has_started(rq)) prio |= I915_PRIORITY_NOSEMAPHORE; - /* Restrict mere WAIT boosts from triggering preemption */ - BUILD_BUG_ON(__NO_PREEMPTION & ~I915_PRIORITY_MASK); /* only internal */ - return prio | __NO_PREEMPTION; + return prio; } static int queue_prio(const struct intel_engine_execlists *execlists) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index aa6d56e25a10..94eb63f309ce 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -258,7 +258,7 @@ static void guc_submit(struct intel_engine_cs *engine, static inline int rq_prio(const struct i915_request *rq) { - return rq->sched.attr.priority | __NO_PREEMPTION; + return rq->sched.attr.priority; } static struct i915_request *schedule_in(struct i915_request *rq, int idx) |