From: Tvrtko Ursulin <[email protected]>
Code added in 71ed60112d5d ("drm/i915: Add kick_backend function to
i915_sched_engine") and ee242ca704d3 ("drm/i915/guc: Implement GuC
priority management") introduced some scheduling related vfuncs which
take integer request priority as argument.
Make them instead take struct i915_sched_attr, which is the type
encapsulating this information, so it probably aligns with the design
better. It definitely enables extending the set of scheduling attributes.
Signed-off-by: Tvrtko Ursulin <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Daniele Ceraolo Spurio <[email protected]>
---
drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 +++-
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 3 ++-
drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
drivers/gpu/drm/i915/i915_scheduler_types.h | 4 ++--
4 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 7147fe80919e..e91d803a6453 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3216,11 +3216,13 @@ static bool can_preempt(struct intel_engine_cs *engine)
return engine->class != RENDER_CLASS;
}
-static void kick_execlists(const struct i915_request *rq, int prio)
+static void kick_execlists(const struct i915_request *rq,
+ const struct i915_sched_attr *attr)
{
struct intel_engine_cs *engine = rq->engine;
struct i915_sched_engine *sched_engine = engine->sched_engine;
const struct i915_request *inflight;
+ const int prio = attr->priority;
/*
* We only need to kick the tasklet once for the high priority
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 ba0de35f6323..b5883a4365ca 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -2414,9 +2414,10 @@ static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
}
static void guc_bump_inflight_request_prio(struct i915_request *rq,
- int prio)
+ const struct i915_sched_attr *attr)
{
struct intel_context *ce = rq->context;
+ const int prio = attr->priority;
u8 new_guc_prio = map_i915_prio_to_guc_prio(prio);
/* Short circuit function */
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index 762127dd56c5..534bab99fcdc 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -255,7 +255,7 @@ static void __i915_schedule(struct i915_sched_node *node,
/* Must be called before changing the nodes priority */
if (sched_engine->bump_inflight_request_prio)
- sched_engine->bump_inflight_request_prio(from, prio);
+ sched_engine->bump_inflight_request_prio(from, attr);
WRITE_ONCE(node->attr.priority, prio);
@@ -280,7 +280,7 @@ static void __i915_schedule(struct i915_sched_node *node,
/* Defer (tasklet) submission until after all of our updates. */
if (sched_engine->kick_backend)
- sched_engine->kick_backend(node_to_request(node), prio);
+ sched_engine->kick_backend(node_to_request(node), attr);
}
spin_unlock(&sched_engine->lock);
diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
index b0a1b58c7893..24b9ac1c2ce2 100644
--- a/drivers/gpu/drm/i915/i915_scheduler_types.h
+++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
@@ -177,13 +177,13 @@ struct i915_sched_engine {
* @kick_backend: kick backend after a request's priority has changed
*/
void (*kick_backend)(const struct i915_request *rq,
- int prio);
+ const struct i915_sched_attr *attr);
/**
* @bump_inflight_request_prio: update priority of an inflight request
*/
void (*bump_inflight_request_prio)(struct i915_request *rq,
- int prio);
+ const struct i915_sched_attr *attr);
/**
* @retire_inflight_request_prio: indicate request is retired to
--
2.30.2
On Mon, Oct 04, 2021 at 03:36:48PM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <[email protected]>
>
> Code added in 71ed60112d5d ("drm/i915: Add kick_backend function to
> i915_sched_engine") and ee242ca704d3 ("drm/i915/guc: Implement GuC
> priority management") introduced some scheduling related vfuncs which
> take integer request priority as argument.
>
> Make them instead take struct i915_sched_attr, which is the type
> encapsulating this information, so it probably aligns with the design
> better. It definitely enables extending the set of scheduling attributes.
>
Understand the motivation here but the i915_scheduler is going to
disapear when we move to the DRM scheduler or at least its functionality
of priority inheritance will be pushed into the DRM scheduler. I'd be
very careful making any changes here as the priority in the DRM
scheduler is defined as single enum:
/* These are often used as an (initial) index
* to an array, and as such should start at 0.
*/
enum drm_sched_priority {
DRM_SCHED_PRIORITY_MIN,
DRM_SCHED_PRIORITY_NORMAL,
DRM_SCHED_PRIORITY_HIGH,
DRM_SCHED_PRIORITY_KERNEL,
DRM_SCHED_PRIORITY_COUNT,
DRM_SCHED_PRIORITY_UNSET = -2
};
Adding a field to the i915_sched_attr is fairly easy as we already have
a structure but changing the DRM scheduler might be a tougher sell.
Anyway you can make this work without adding the 'nice' field to
i915_sched_attr? Might be worth exploring so when we move to the DRM
scheduler this feature drops in a little cleaner.
Matt
> Signed-off-by: Tvrtko Ursulin <[email protected]>
> Cc: Matthew Brost <[email protected]>
> Cc: Daniele Ceraolo Spurio <[email protected]>
> ---
> drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 +++-
> drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 3 ++-
> drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
> drivers/gpu/drm/i915/i915_scheduler_types.h | 4 ++--
> 4 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index 7147fe80919e..e91d803a6453 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -3216,11 +3216,13 @@ static bool can_preempt(struct intel_engine_cs *engine)
> return engine->class != RENDER_CLASS;
> }
>
> -static void kick_execlists(const struct i915_request *rq, int prio)
> +static void kick_execlists(const struct i915_request *rq,
> + const struct i915_sched_attr *attr)
> {
> struct intel_engine_cs *engine = rq->engine;
> struct i915_sched_engine *sched_engine = engine->sched_engine;
> const struct i915_request *inflight;
> + const int prio = attr->priority;
>
> /*
> * We only need to kick the tasklet once for the high priority
> 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 ba0de35f6323..b5883a4365ca 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -2414,9 +2414,10 @@ static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
> }
>
> static void guc_bump_inflight_request_prio(struct i915_request *rq,
> - int prio)
> + const struct i915_sched_attr *attr)
> {
> struct intel_context *ce = rq->context;
> + const int prio = attr->priority;
> u8 new_guc_prio = map_i915_prio_to_guc_prio(prio);
>
> /* Short circuit function */
> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
> index 762127dd56c5..534bab99fcdc 100644
> --- a/drivers/gpu/drm/i915/i915_scheduler.c
> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
> @@ -255,7 +255,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>
> /* Must be called before changing the nodes priority */
> if (sched_engine->bump_inflight_request_prio)
> - sched_engine->bump_inflight_request_prio(from, prio);
> + sched_engine->bump_inflight_request_prio(from, attr);
>
> WRITE_ONCE(node->attr.priority, prio);
>
> @@ -280,7 +280,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>
> /* Defer (tasklet) submission until after all of our updates. */
> if (sched_engine->kick_backend)
> - sched_engine->kick_backend(node_to_request(node), prio);
> + sched_engine->kick_backend(node_to_request(node), attr);
> }
>
> spin_unlock(&sched_engine->lock);
> diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
> index b0a1b58c7893..24b9ac1c2ce2 100644
> --- a/drivers/gpu/drm/i915/i915_scheduler_types.h
> +++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
> @@ -177,13 +177,13 @@ struct i915_sched_engine {
> * @kick_backend: kick backend after a request's priority has changed
> */
> void (*kick_backend)(const struct i915_request *rq,
> - int prio);
> + const struct i915_sched_attr *attr);
>
> /**
> * @bump_inflight_request_prio: update priority of an inflight request
> */
> void (*bump_inflight_request_prio)(struct i915_request *rq,
> - int prio);
> + const struct i915_sched_attr *attr);
>
> /**
> * @retire_inflight_request_prio: indicate request is retired to
> --
> 2.30.2
>
On 06/10/2021 18:12, Matthew Brost wrote:
> On Mon, Oct 04, 2021 at 03:36:48PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <[email protected]>
>>
>> Code added in 71ed60112d5d ("drm/i915: Add kick_backend function to
>> i915_sched_engine") and ee242ca704d3 ("drm/i915/guc: Implement GuC
>> priority management") introduced some scheduling related vfuncs which
>> take integer request priority as argument.
>>
>> Make them instead take struct i915_sched_attr, which is the type
>> encapsulating this information, so it probably aligns with the design
>> better. It definitely enables extending the set of scheduling attributes.
>>
>
> Understand the motivation here but the i915_scheduler is going to
> disapear when we move to the DRM scheduler or at least its functionality
> of priority inheritance will be pushed into the DRM scheduler. I'd be
> very careful making any changes here as the priority in the DRM
> scheduler is defined as single enum:
>
> /* These are often used as an (initial) index
> * to an array, and as such should start at 0.
> */
> enum drm_sched_priority {
> DRM_SCHED_PRIORITY_MIN,
> DRM_SCHED_PRIORITY_NORMAL,
> DRM_SCHED_PRIORITY_HIGH,
> DRM_SCHED_PRIORITY_KERNEL,
>
> DRM_SCHED_PRIORITY_COUNT,
> DRM_SCHED_PRIORITY_UNSET = -2
> };
>
> Adding a field to the i915_sched_attr is fairly easy as we already have
> a structure but changing the DRM scheduler might be a tougher sell.
> Anyway you can make this work without adding the 'nice' field to
> i915_sched_attr? Might be worth exploring so when we move to the DRM
> scheduler this feature drops in a little cleaner.
/me rubs a crystal ball.. no idea how that would look. :)
Idea with separate nice in sched attr is that only default priority
contexts are affected by nice. Thinking being, if i915 aware userspace
has explicitly requested a different priority, then let it keep that. In
other words, only if it did not bother and left it at default/normal,
then we inherit from process nice.
I suppose to keep this idea in some future drm scheduler world it would
require some work. But in general the concept is of course open to
discussion.
Implementation wise, not having prio and nice separate opens some other
problems in how this interacts with GEM context priority, but there are
probably solutions to those problems as well.
I suppose I could define a "nice range" in the existing priorities and
nice adjustments would only apply if within that range. That would allow
max and min user priority to still be undisturbed as requested via the
i915 uapi.
(min) -1023 ----- (nice 20) ----- 0 ------ (nice -19) ------ +1023 (max)
And I say if some userspace set a priority in the -20 to 19 range then
it is allowed to adjust it via process nice. That would keep it a single
int priority as today.
Regards,
Tvrtko
>
> Matt
>
>> Signed-off-by: Tvrtko Ursulin <[email protected]>
>> Cc: Matthew Brost <[email protected]>
>> Cc: Daniele Ceraolo Spurio <[email protected]>
>> ---
>> drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 +++-
>> drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 3 ++-
>> drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
>> drivers/gpu/drm/i915/i915_scheduler_types.h | 4 ++--
>> 4 files changed, 9 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>> index 7147fe80919e..e91d803a6453 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>> @@ -3216,11 +3216,13 @@ static bool can_preempt(struct intel_engine_cs *engine)
>> return engine->class != RENDER_CLASS;
>> }
>>
>> -static void kick_execlists(const struct i915_request *rq, int prio)
>> +static void kick_execlists(const struct i915_request *rq,
>> + const struct i915_sched_attr *attr)
>> {
>> struct intel_engine_cs *engine = rq->engine;
>> struct i915_sched_engine *sched_engine = engine->sched_engine;
>> const struct i915_request *inflight;
>> + const int prio = attr->priority;
>>
>> /*
>> * We only need to kick the tasklet once for the high priority
>> 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 ba0de35f6323..b5883a4365ca 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> @@ -2414,9 +2414,10 @@ static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
>> }
>>
>> static void guc_bump_inflight_request_prio(struct i915_request *rq,
>> - int prio)
>> + const struct i915_sched_attr *attr)
>> {
>> struct intel_context *ce = rq->context;
>> + const int prio = attr->priority;
>> u8 new_guc_prio = map_i915_prio_to_guc_prio(prio);
>>
>> /* Short circuit function */
>> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
>> index 762127dd56c5..534bab99fcdc 100644
>> --- a/drivers/gpu/drm/i915/i915_scheduler.c
>> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
>> @@ -255,7 +255,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>>
>> /* Must be called before changing the nodes priority */
>> if (sched_engine->bump_inflight_request_prio)
>> - sched_engine->bump_inflight_request_prio(from, prio);
>> + sched_engine->bump_inflight_request_prio(from, attr);
>>
>> WRITE_ONCE(node->attr.priority, prio);
>>
>> @@ -280,7 +280,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>>
>> /* Defer (tasklet) submission until after all of our updates. */
>> if (sched_engine->kick_backend)
>> - sched_engine->kick_backend(node_to_request(node), prio);
>> + sched_engine->kick_backend(node_to_request(node), attr);
>> }
>>
>> spin_unlock(&sched_engine->lock);
>> diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
>> index b0a1b58c7893..24b9ac1c2ce2 100644
>> --- a/drivers/gpu/drm/i915/i915_scheduler_types.h
>> +++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
>> @@ -177,13 +177,13 @@ struct i915_sched_engine {
>> * @kick_backend: kick backend after a request's priority has changed
>> */
>> void (*kick_backend)(const struct i915_request *rq,
>> - int prio);
>> + const struct i915_sched_attr *attr);
>>
>> /**
>> * @bump_inflight_request_prio: update priority of an inflight request
>> */
>> void (*bump_inflight_request_prio)(struct i915_request *rq,
>> - int prio);
>> + const struct i915_sched_attr *attr);
>>
>> /**
>> * @retire_inflight_request_prio: indicate request is retired to
>> --
>> 2.30.2
>>
On Wed, Oct 06, 2021 at 10:12:29AM -0700, Matthew Brost wrote:
> On Mon, Oct 04, 2021 at 03:36:48PM +0100, Tvrtko Ursulin wrote:
> > From: Tvrtko Ursulin <[email protected]>
> >
> > Code added in 71ed60112d5d ("drm/i915: Add kick_backend function to
> > i915_sched_engine") and ee242ca704d3 ("drm/i915/guc: Implement GuC
> > priority management") introduced some scheduling related vfuncs which
> > take integer request priority as argument.
> >
> > Make them instead take struct i915_sched_attr, which is the type
> > encapsulating this information, so it probably aligns with the design
> > better. It definitely enables extending the set of scheduling attributes.
> >
>
> Understand the motivation here but the i915_scheduler is going to
> disapear when we move to the DRM scheduler or at least its functionality
> of priority inheritance will be pushed into the DRM scheduler. I'd be
> very careful making any changes here as the priority in the DRM
> scheduler is defined as single enum:
Yeah I'm not sure it makes sense to build this and make the conversion to
drm/sched even harder. We've already merged a lot of code with a "we'll
totally convert to drm/sched right after" promise, there's not really room
for more fun like this built on top of i915-scheduler.
-Daniel
>
> /* These are often used as an (initial) index
> * to an array, and as such should start at 0.
> */
> enum drm_sched_priority {
> DRM_SCHED_PRIORITY_MIN,
> DRM_SCHED_PRIORITY_NORMAL,
> DRM_SCHED_PRIORITY_HIGH,
> DRM_SCHED_PRIORITY_KERNEL,
>
> DRM_SCHED_PRIORITY_COUNT,
> DRM_SCHED_PRIORITY_UNSET = -2
> };
>
> Adding a field to the i915_sched_attr is fairly easy as we already have
> a structure but changing the DRM scheduler might be a tougher sell.
> Anyway you can make this work without adding the 'nice' field to
> i915_sched_attr? Might be worth exploring so when we move to the DRM
> scheduler this feature drops in a little cleaner.
>
> Matt
>
> > Signed-off-by: Tvrtko Ursulin <[email protected]>
> > Cc: Matthew Brost <[email protected]>
> > Cc: Daniele Ceraolo Spurio <[email protected]>
> > ---
> > drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 +++-
> > drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 3 ++-
> > drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
> > drivers/gpu/drm/i915/i915_scheduler_types.h | 4 ++--
> > 4 files changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > index 7147fe80919e..e91d803a6453 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > @@ -3216,11 +3216,13 @@ static bool can_preempt(struct intel_engine_cs *engine)
> > return engine->class != RENDER_CLASS;
> > }
> >
> > -static void kick_execlists(const struct i915_request *rq, int prio)
> > +static void kick_execlists(const struct i915_request *rq,
> > + const struct i915_sched_attr *attr)
> > {
> > struct intel_engine_cs *engine = rq->engine;
> > struct i915_sched_engine *sched_engine = engine->sched_engine;
> > const struct i915_request *inflight;
> > + const int prio = attr->priority;
> >
> > /*
> > * We only need to kick the tasklet once for the high priority
> > 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 ba0de35f6323..b5883a4365ca 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > @@ -2414,9 +2414,10 @@ static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
> > }
> >
> > static void guc_bump_inflight_request_prio(struct i915_request *rq,
> > - int prio)
> > + const struct i915_sched_attr *attr)
> > {
> > struct intel_context *ce = rq->context;
> > + const int prio = attr->priority;
> > u8 new_guc_prio = map_i915_prio_to_guc_prio(prio);
> >
> > /* Short circuit function */
> > diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
> > index 762127dd56c5..534bab99fcdc 100644
> > --- a/drivers/gpu/drm/i915/i915_scheduler.c
> > +++ b/drivers/gpu/drm/i915/i915_scheduler.c
> > @@ -255,7 +255,7 @@ static void __i915_schedule(struct i915_sched_node *node,
> >
> > /* Must be called before changing the nodes priority */
> > if (sched_engine->bump_inflight_request_prio)
> > - sched_engine->bump_inflight_request_prio(from, prio);
> > + sched_engine->bump_inflight_request_prio(from, attr);
> >
> > WRITE_ONCE(node->attr.priority, prio);
> >
> > @@ -280,7 +280,7 @@ static void __i915_schedule(struct i915_sched_node *node,
> >
> > /* Defer (tasklet) submission until after all of our updates. */
> > if (sched_engine->kick_backend)
> > - sched_engine->kick_backend(node_to_request(node), prio);
> > + sched_engine->kick_backend(node_to_request(node), attr);
> > }
> >
> > spin_unlock(&sched_engine->lock);
> > diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
> > index b0a1b58c7893..24b9ac1c2ce2 100644
> > --- a/drivers/gpu/drm/i915/i915_scheduler_types.h
> > +++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
> > @@ -177,13 +177,13 @@ struct i915_sched_engine {
> > * @kick_backend: kick backend after a request's priority has changed
> > */
> > void (*kick_backend)(const struct i915_request *rq,
> > - int prio);
> > + const struct i915_sched_attr *attr);
> >
> > /**
> > * @bump_inflight_request_prio: update priority of an inflight request
> > */
> > void (*bump_inflight_request_prio)(struct i915_request *rq,
> > - int prio);
> > + const struct i915_sched_attr *attr);
> >
> > /**
> > * @retire_inflight_request_prio: indicate request is retired to
> > --
> > 2.30.2
> >
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
On 13/10/2021 13:01, Daniel Vetter wrote:
> On Wed, Oct 06, 2021 at 10:12:29AM -0700, Matthew Brost wrote:
>> On Mon, Oct 04, 2021 at 03:36:48PM +0100, Tvrtko Ursulin wrote:
>>> From: Tvrtko Ursulin <[email protected]>
>>>
>>> Code added in 71ed60112d5d ("drm/i915: Add kick_backend function to
>>> i915_sched_engine") and ee242ca704d3 ("drm/i915/guc: Implement GuC
>>> priority management") introduced some scheduling related vfuncs which
>>> take integer request priority as argument.
>>>
>>> Make them instead take struct i915_sched_attr, which is the type
>>> encapsulating this information, so it probably aligns with the design
>>> better. It definitely enables extending the set of scheduling attributes.
>>>
>>
>> Understand the motivation here but the i915_scheduler is going to
>> disapear when we move to the DRM scheduler or at least its functionality
>> of priority inheritance will be pushed into the DRM scheduler. I'd be
>> very careful making any changes here as the priority in the DRM
>> scheduler is defined as single enum:
>
> Yeah I'm not sure it makes sense to build this and make the conversion to
> drm/sched even harder. We've already merged a lot of code with a "we'll
> totally convert to drm/sched right after" promise, there's not really room
> for more fun like this built on top of i915-scheduler.
It is not really fun on top of i915-scheduler. It is fun on top of the
concept of uapi gem context priority. As long as there is gem context
priority, and requests inherit from it, the concept works. This is
demonstrated by the fact it ties in with the GuC backend which reduces
to three priorities already. It is limited granularity but it does
something.
Implementation details aside, key question is the proposal to tie
process nice with GPU scheduling priority. There seems to be interest
from other parties so there probably is something here.
But I do plan to simplify this RFC to not add anything to
i915_sched_attr and also drop the task sched attr change notifier.
Regards,
Tvrtko
> -Daniel
>
>>
>> /* These are often used as an (initial) index
>> * to an array, and as such should start at 0.
>> */
>> enum drm_sched_priority {
>> DRM_SCHED_PRIORITY_MIN,
>> DRM_SCHED_PRIORITY_NORMAL,
>> DRM_SCHED_PRIORITY_HIGH,
>> DRM_SCHED_PRIORITY_KERNEL,
>>
>> DRM_SCHED_PRIORITY_COUNT,
>> DRM_SCHED_PRIORITY_UNSET = -2
>> };
>>
>> Adding a field to the i915_sched_attr is fairly easy as we already have
>> a structure but changing the DRM scheduler might be a tougher sell.
>> Anyway you can make this work without adding the 'nice' field to
>> i915_sched_attr? Might be worth exploring so when we move to the DRM
>> scheduler this feature drops in a little cleaner.
>>
>> Matt
>>
>>> Signed-off-by: Tvrtko Ursulin <[email protected]>
>>> Cc: Matthew Brost <[email protected]>
>>> Cc: Daniele Ceraolo Spurio <[email protected]>
>>> ---
>>> drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 +++-
>>> drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 3 ++-
>>> drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
>>> drivers/gpu/drm/i915/i915_scheduler_types.h | 4 ++--
>>> 4 files changed, 9 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> index 7147fe80919e..e91d803a6453 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> @@ -3216,11 +3216,13 @@ static bool can_preempt(struct intel_engine_cs *engine)
>>> return engine->class != RENDER_CLASS;
>>> }
>>>
>>> -static void kick_execlists(const struct i915_request *rq, int prio)
>>> +static void kick_execlists(const struct i915_request *rq,
>>> + const struct i915_sched_attr *attr)
>>> {
>>> struct intel_engine_cs *engine = rq->engine;
>>> struct i915_sched_engine *sched_engine = engine->sched_engine;
>>> const struct i915_request *inflight;
>>> + const int prio = attr->priority;
>>>
>>> /*
>>> * We only need to kick the tasklet once for the high priority
>>> 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 ba0de35f6323..b5883a4365ca 100644
>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>>> @@ -2414,9 +2414,10 @@ static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
>>> }
>>>
>>> static void guc_bump_inflight_request_prio(struct i915_request *rq,
>>> - int prio)
>>> + const struct i915_sched_attr *attr)
>>> {
>>> struct intel_context *ce = rq->context;
>>> + const int prio = attr->priority;
>>> u8 new_guc_prio = map_i915_prio_to_guc_prio(prio);
>>>
>>> /* Short circuit function */
>>> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
>>> index 762127dd56c5..534bab99fcdc 100644
>>> --- a/drivers/gpu/drm/i915/i915_scheduler.c
>>> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
>>> @@ -255,7 +255,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>>>
>>> /* Must be called before changing the nodes priority */
>>> if (sched_engine->bump_inflight_request_prio)
>>> - sched_engine->bump_inflight_request_prio(from, prio);
>>> + sched_engine->bump_inflight_request_prio(from, attr);
>>>
>>> WRITE_ONCE(node->attr.priority, prio);
>>>
>>> @@ -280,7 +280,7 @@ static void __i915_schedule(struct i915_sched_node *node,
>>>
>>> /* Defer (tasklet) submission until after all of our updates. */
>>> if (sched_engine->kick_backend)
>>> - sched_engine->kick_backend(node_to_request(node), prio);
>>> + sched_engine->kick_backend(node_to_request(node), attr);
>>> }
>>>
>>> spin_unlock(&sched_engine->lock);
>>> diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
>>> index b0a1b58c7893..24b9ac1c2ce2 100644
>>> --- a/drivers/gpu/drm/i915/i915_scheduler_types.h
>>> +++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
>>> @@ -177,13 +177,13 @@ struct i915_sched_engine {
>>> * @kick_backend: kick backend after a request's priority has changed
>>> */
>>> void (*kick_backend)(const struct i915_request *rq,
>>> - int prio);
>>> + const struct i915_sched_attr *attr);
>>>
>>> /**
>>> * @bump_inflight_request_prio: update priority of an inflight request
>>> */
>>> void (*bump_inflight_request_prio)(struct i915_request *rq,
>>> - int prio);
>>> + const struct i915_sched_attr *attr);
>>>
>>> /**
>>> * @retire_inflight_request_prio: indicate request is retired to
>>> --
>>> 2.30.2
>>>
>