Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > On finishing the reset, the intention is to restart the GPU before we > relinquish the forcewake taken to handle the reset - the goal being the > GPU reloads a context before it is allowed to sleep. For this purpose, > we used tasklet_flush() which although it accomplished the goal of > restarting the GPU, carried with it a sting in its tail: it cleared the > TASKLET_STATE_SCHED bit. This meant that if another CPU queued a new > request to this engine, we would clear the flag and later attempt to > requeue the tasklet on the local CPU, breaking the per-cpu softirq > lists. > > Remove the dangerous tasklet_kill() and just run the tasklet func > directly as we know it is safe to do so (the tasklets are internally > locked to allow mixed usage from direct submission). > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107710 > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> > Cc: Michel Thierry <michel.thierry@xxxxxxxxx> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_gem.h | 6 ------ > drivers/gpu/drm/i915/intel_lrc.c | 17 ++++++----------- > 2 files changed, 6 insertions(+), 17 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h > index e46592956872..599c4f6eb1ea 100644 > --- a/drivers/gpu/drm/i915/i915_gem.h > +++ b/drivers/gpu/drm/i915/i915_gem.h > @@ -82,12 +82,6 @@ static inline void __tasklet_disable_sync_once(struct tasklet_struct *t) > tasklet_unlock_wait(t); > } > > -static inline void __tasklet_enable_sync_once(struct tasklet_struct *t) > -{ > - if (atomic_dec_return(&t->count) == 0) > - tasklet_kill(t); > -} > - > static inline bool __tasklet_is_enabled(const struct tasklet_struct *t) > { > return !atomic_read(&t->count); > diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c > index 36050f085071..f8ceb9c99dd6 100644 > --- a/drivers/gpu/drm/i915/intel_lrc.c > +++ b/drivers/gpu/drm/i915/intel_lrc.c > @@ -1962,21 +1962,16 @@ static void execlists_reset_finish(struct intel_engine_cs *engine) > { > struct intel_engine_execlists * const execlists = &engine->execlists; > > - /* After a GPU reset, we may have requests to replay */ > - if (!RB_EMPTY_ROOT(&execlists->queue.rb_root)) > - tasklet_schedule(&execlists->tasklet); > - > /* > - * Flush the tasklet while we still have the forcewake to be sure > - * that it is not allowed to sleep before we restart and reload a > - * context. > + * After a GPU reset, we may have requests to replay. Do so now while > + * we still have the forcewake to be sure that the GPU is not allowed > + * to sleep before we restart and reload a context. > * > - * As before (with execlists_reset_prepare) we rely on the caller > - * serialising multiple attempts to reset so that we know that we > - * are the only one manipulating tasklet state. > */ > - __tasklet_enable_sync_once(&execlists->tasklet); > + if (!RB_EMPTY_ROOT(&execlists->queue.rb_root)) > + execlists->tasklet.func(execlists->tasklet.data); The enabling right after should be enough of a hint that we can do this. Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> > > + tasklet_enable(&execlists->tasklet); > GEM_TRACE("%s: depth->%d\n", engine->name, > atomic_read(&execlists->tasklet.count)); > } > -- > 2.18.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
