| Message ID | 20240711051215.1143127-1-nitin.r.gote@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/gt: Do not consider preemption during execlists_dequeue for gen8 | expand |
On 11/07/2024 06:12, Nitin Gote wrote: > We're seeing a GPU HANG issue on a CHV platform, which was caused by > bac24f59f454 ("drm/i915/execlists: Enable coarse preemption boundaries for gen8"). > > Gen8 platform has only timeslice and doesn't support a preemption mechanism > as engines do not have a preemption timer and doesn't send an irq if the > preemption timeout expires. So, add a fix to not consider preemption > during dequeuing for gen8 platforms. > > Also move can_preemt() above need_preempt() function to resolve implicit > declaration of function ‘can_preempt' error and make can_preempt() > function param as const to resolve error: passing argument 1 of > ‘can_preempt’ discards ‘const’ qualifier from the pointer target type. > > v2: Simplify can_preemt() function (Tvrtko Ursulin) Yeah sorry for that yesterday when I thought gen8 emit bb was dead code, somehow I thought there was a gen9 emit_bb flavour. Looks like I confused it with something else. > > Fixes: bac24f59f454 ("drm/i915/execlists: Enable coarse preemption boundaries for gen8") > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11396 > Suggested-by: Andi Shyti <andi.shyti@intel.com> > Signed-off-by: Nitin Gote <nitin.r.gote@intel.com> > Cc: Chris Wilson <chris.p.wilson@linux.intel.com> > CC: <stable@vger.kernel.org> # v5.2+ > --- > .../drm/i915/gt/intel_execlists_submission.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > index 21829439e686..59885d7721e4 100644 > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > @@ -294,11 +294,19 @@ static int virtual_prio(const struct intel_engine_execlists *el) > return rb ? rb_entry(rb, struct ve_node, rb)->prio : INT_MIN; > } > > +static bool can_preempt(const struct intel_engine_cs *engine) > +{ > + return GRAPHICS_VER(engine->i915) > 8; > +} > + > static bool need_preempt(const struct intel_engine_cs *engine, > const struct i915_request *rq) > { > int last_prio; > > + if (!can_preempt(engine)) > + return false; > + > if (!intel_engine_has_semaphores(engine)) Patch looks clean now. Hmmm one new observation is whether the "has semaphores" check is now redundant? Looks preemption depends on semaphore support in logical_ring_default_vfuncs(). Regards, Tvrtko > return false; > > @@ -3313,15 +3321,6 @@ static void remove_from_engine(struct i915_request *rq) > i915_request_notify_execute_cb_imm(rq); > } > > -static bool can_preempt(struct intel_engine_cs *engine) > -{ > - if (GRAPHICS_VER(engine->i915) > 8) > - return true; > - > - /* GPGPU on bdw requires extra w/a; not implemented */ > - return engine->class != RENDER_CLASS; > -} > - > static void kick_execlists(const struct i915_request *rq, int prio) > { > struct intel_engine_cs *engine = rq->engine;
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index 21829439e686..59885d7721e4 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -294,11 +294,19 @@ static int virtual_prio(const struct intel_engine_execlists *el) return rb ? rb_entry(rb, struct ve_node, rb)->prio : INT_MIN; } +static bool can_preempt(const struct intel_engine_cs *engine) +{ + return GRAPHICS_VER(engine->i915) > 8; +} + static bool need_preempt(const struct intel_engine_cs *engine, const struct i915_request *rq) { int last_prio; + if (!can_preempt(engine)) + return false; + if (!intel_engine_has_semaphores(engine)) return false; @@ -3313,15 +3321,6 @@ static void remove_from_engine(struct i915_request *rq) i915_request_notify_execute_cb_imm(rq); } -static bool can_preempt(struct intel_engine_cs *engine) -{ - if (GRAPHICS_VER(engine->i915) > 8) - return true; - - /* GPGPU on bdw requires extra w/a; not implemented */ - return engine->class != RENDER_CLASS; -} - static void kick_execlists(const struct i915_request *rq, int prio) { struct intel_engine_cs *engine = rq->engine;
We're seeing a GPU HANG issue on a CHV platform, which was caused by bac24f59f454 ("drm/i915/execlists: Enable coarse preemption boundaries for gen8"). Gen8 platform has only timeslice and doesn't support a preemption mechanism as engines do not have a preemption timer and doesn't send an irq if the preemption timeout expires. So, add a fix to not consider preemption during dequeuing for gen8 platforms. Also move can_preemt() above need_preempt() function to resolve implicit declaration of function ‘can_preempt' error and make can_preempt() function param as const to resolve error: passing argument 1 of ‘can_preempt’ discards ‘const’ qualifier from the pointer target type. v2: Simplify can_preemt() function (Tvrtko Ursulin) Fixes: bac24f59f454 ("drm/i915/execlists: Enable coarse preemption boundaries for gen8") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11396 Suggested-by: Andi Shyti <andi.shyti@intel.com> Signed-off-by: Nitin Gote <nitin.r.gote@intel.com> Cc: Chris Wilson <chris.p.wilson@linux.intel.com> CC: <stable@vger.kernel.org> # v5.2+ --- .../drm/i915/gt/intel_execlists_submission.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)