| Message ID | 20191014220534.1662-9-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/10] drm/i915/gem: Distinguish each object type | expand |
On 14/10/2019 23:05, Chris Wilson wrote: > We perform timeslicing immediately upon receipt of a request that may be > put into the second ELSP slot. The idea behind this was that since we > didn't install the timer if the second ELSP slot was empty, we would not > have any idea of how long ELSP[0] had been running and so giving the > newcomer a chance on the GPU was fair. However, this causes us extra > busy work that we may be able to avoid if we wait a jiffie for the first > timeslice as normal. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 60e897c000b2..f9bf78032ad7 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -1613,7 +1613,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine) > last->hw_context->lrc_desc |= CTX_DESC_FORCE_RESTORE; > last = NULL; > } else if (need_timeslice(engine, last) && > - !timer_pending(&engine->execlists.timer)) { > + timer_expired(&engine->execlists.timer)) { timer_expired is !timer_pending(..) && t->expires. Presumably that means it was scheduled at least once in the past but currently isn't. Then immediately after the first timer the t->expires check becomes useless? I must be missing something.. Oh, you have piggy-backed some custom code to timers.. hm.. Looks like it would work. Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko > GEM_TRACE("%s: expired last=%llx:%lld, prio=%d, hint=%d\n", > engine->name, > last->fence.context, > @@ -2074,6 +2074,8 @@ static void process_csb(struct intel_engine_cs *engine) > > if (enable_timeslice(execlists)) > mod_timer(&execlists->timer, jiffies + 1); > + else > + cancel_timer(&execlists->timer); > > WRITE_ONCE(execlists->pending[0], NULL); > } else { > @@ -3591,7 +3593,7 @@ gen12_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs) > > static void execlists_park(struct intel_engine_cs *engine) > { > - del_timer(&engine->execlists.timer); > + cancel_timer(&engine->execlists.timer); > cancel_timer(&engine->execlists.preempt); > } > >
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 60e897c000b2..f9bf78032ad7 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1613,7 +1613,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine) last->hw_context->lrc_desc |= CTX_DESC_FORCE_RESTORE; last = NULL; } else if (need_timeslice(engine, last) && - !timer_pending(&engine->execlists.timer)) { + timer_expired(&engine->execlists.timer)) { GEM_TRACE("%s: expired last=%llx:%lld, prio=%d, hint=%d\n", engine->name, last->fence.context, @@ -2074,6 +2074,8 @@ static void process_csb(struct intel_engine_cs *engine) if (enable_timeslice(execlists)) mod_timer(&execlists->timer, jiffies + 1); + else + cancel_timer(&execlists->timer); WRITE_ONCE(execlists->pending[0], NULL); } else { @@ -3591,7 +3593,7 @@ gen12_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs) static void execlists_park(struct intel_engine_cs *engine) { - del_timer(&engine->execlists.timer); + cancel_timer(&engine->execlists.timer); cancel_timer(&engine->execlists.preempt); }
We perform timeslicing immediately upon receipt of a request that may be put into the second ELSP slot. The idea behind this was that since we didn't install the timer if the second ELSP slot was empty, we would not have any idea of how long ELSP[0] had been running and so giving the newcomer a chance on the GPU was fair. However, this causes us extra busy work that we may be able to avoid if we wait a jiffie for the first timeslice as normal. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/gt/intel_lrc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)