| Message ID | 20220614004616.45561-1-umesh.nerlige.ramappa@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i915/pmu: Wire GuC backend to per-client busyness | expand |
On 14/06/2022 01:46, Nerlige Ramappa, Umesh wrote: > From: John Harrison <John.C.Harrison@Intel.com> > > GuC provides engine_id and last_switch_in ticks for an active context in the > pphwsp. The context image provides a 32 bit total ticks which is the accumulated > by the context (a.k.a. context[CTX_TIMESTAMP]). This information is used to > calculate the context busyness as follows: > > If the engine_id is valid, then busyness is the sum of accumulated total ticks > and active ticks. Active ticks is calculated with current gt time as reference. > > If engine_id is invalid, busyness is equal to accumulated total ticks. > > Since KMD (CPU) retrieves busyness data from 2 sources - GPU and GuC, a > potential race was highlighted in an earlier review that can lead to double > accounting of busyness. While the solution to this is a wip, busyness is still > usable for platforms running GuC submission. > > Signed-off-by: John Harrison <John.C.Harrison@Intel.com> > Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_context.c | 11 +++- > drivers/gpu/drm/i915/gt/intel_context.h | 6 +- > drivers/gpu/drm/i915/gt/intel_context_types.h | 3 + > drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 5 ++ > .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 55 ++++++++++++++++++- > drivers/gpu/drm/i915/i915_drm_client.c | 6 +- > 6 files changed, 75 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c > index 4070cb5711d8..a49f313db911 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context.c > +++ b/drivers/gpu/drm/i915/gt/intel_context.c > @@ -576,16 +576,23 @@ void intel_context_bind_parent_child(struct intel_context *parent, > child->parallel.parent = parent; > } > > -u64 intel_context_get_total_runtime_ns(const struct intel_context *ce) > +u64 intel_context_get_total_runtime_ns(struct intel_context *ce) > { > u64 total, active; > > + if (ce->ops->update_stats) > + ce->ops->update_stats(ce); > + > total = ce->stats.runtime.total; > if (ce->ops->flags & COPS_RUNTIME_CYCLES) > total *= ce->engine->gt->clock_period_ns; > > active = READ_ONCE(ce->stats.active); > - if (active) > + /* > + * GuC backend returns the actual time the context was active, so skip > + * the calculation here for GuC. > + */ > + if (active && !intel_engine_uses_guc(ce->engine)) What is the point of looking at ce->stats.active in GuC mode? I see that guc_context_update_stats/__guc_context_update_clks touches it, but I can't spot that there is a purpose to it. This is the only conditional reading it but it is short-circuited in GuC case. Also, since a GuC only vfunc (update_stats) has been added, I wonder why not just fork the whole runtime query (ce->get_total_runtime_ns). I think that would end up cleaner. > active = intel_context_clock() - active; > > return total + active; > diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h > index b7d3214d2cdd..5fc7c19ab29b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context.h > +++ b/drivers/gpu/drm/i915/gt/intel_context.h > @@ -56,7 +56,7 @@ static inline bool intel_context_is_parent(struct intel_context *ce) > return !!ce->parallel.number_children; > } > > -static inline bool intel_context_is_pinned(struct intel_context *ce); > +static inline bool intel_context_is_pinned(const struct intel_context *ce); > > static inline struct intel_context * > intel_context_to_parent(struct intel_context *ce) > @@ -116,7 +116,7 @@ static inline int intel_context_lock_pinned(struct intel_context *ce) > * Returns: true if the context is currently pinned for use by the GPU. > */ > static inline bool > -intel_context_is_pinned(struct intel_context *ce) > +intel_context_is_pinned(const struct intel_context *ce) > { > return atomic_read(&ce->pin_count); > } > @@ -351,7 +351,7 @@ intel_context_clear_nopreempt(struct intel_context *ce) > clear_bit(CONTEXT_NOPREEMPT, &ce->flags); > } > > -u64 intel_context_get_total_runtime_ns(const struct intel_context *ce); > +u64 intel_context_get_total_runtime_ns(struct intel_context *ce); > u64 intel_context_get_avg_runtime_ns(struct intel_context *ce); > > static inline u64 intel_context_clock(void) > diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h > index 09f82545789f..0a3290c99a31 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context_types.h > +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h > @@ -55,6 +55,8 @@ struct intel_context_ops { > > void (*sched_disable)(struct intel_context *ce); > > + void (*update_stats)(struct intel_context *ce); > + > void (*reset)(struct intel_context *ce); > void (*destroy)(struct kref *kref); > > @@ -146,6 +148,7 @@ struct intel_context { > struct ewma_runtime avg; > u64 total; > u32 last; > + u64 start_gt_clk; > I915_SELFTEST_DECLARE(u32 num_underflow); > I915_SELFTEST_DECLARE(u32 max_underflow); > } runtime; > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > index b3c9a9327f76..6231ad03e4eb 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > @@ -196,6 +196,11 @@ static inline u8 guc_class_to_engine_class(u8 guc_class) > return guc_class_engine_class_map[guc_class]; > } > > +/* Per context engine usage stats: */ > +#define PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO (0x500 / sizeof(u32)) > +#define PPHWSP_GUC_CONTEXT_USAGE_STAMP_HI (PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO + 1) > +#define PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID (PPHWSP_GUC_CONTEXT_USAGE_STAMP_HI + 1) > + > /* Work item for submitting workloads into work queue of GuC. */ > struct guc_wq_item { > u32 header; > 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 5a1dfacf24ea..b86401144417 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > @@ -378,7 +378,7 @@ static inline void set_context_guc_id_invalid(struct intel_context *ce) > ce->guc_id.id = GUC_INVALID_CONTEXT_ID; > } > > -static inline struct intel_guc *ce_to_guc(struct intel_context *ce) > +static inline struct intel_guc *ce_to_guc(const struct intel_context *ce) > { > return &ce->engine->gt->uc.guc; > } > @@ -1323,13 +1323,16 @@ static void __update_guc_busyness_stats(struct intel_guc *guc) > spin_unlock_irqrestore(&guc->timestamp.lock, flags); > } > > +static void __guc_context_update_clks(struct intel_context *ce); > static void guc_timestamp_ping(struct work_struct *wrk) > { > struct intel_guc *guc = container_of(wrk, typeof(*guc), > timestamp.work.work); > struct intel_uc *uc = container_of(guc, typeof(*uc), guc); > struct intel_gt *gt = guc_to_gt(guc); > + struct intel_context *ce; > intel_wakeref_t wakeref; > + unsigned long index; > int srcu, ret; > > /* > @@ -1343,6 +1346,10 @@ static void guc_timestamp_ping(struct work_struct *wrk) > with_intel_runtime_pm(>->i915->runtime_pm, wakeref) > __update_guc_busyness_stats(guc); > > + /* adjust context stats for overflow */ > + xa_for_each(&guc->context_lookup, index, ce) > + __guc_context_update_clks(ce); > + > intel_gt_reset_unlock(gt, srcu); > > mod_delayed_work(system_highpri_wq, &guc->timestamp.work, > @@ -1405,6 +1412,48 @@ void intel_guc_busyness_unpark(struct intel_gt *gt) > guc->timestamp.ping_delay); > } > > +static void __guc_context_update_clks(struct intel_context *ce) > +{ > + struct intel_guc *guc = ce_to_guc(ce); > + struct intel_gt *gt = ce->engine->gt; > + u32 *pphwsp, last_switch, engine_id; > + u64 start_gt_clk = 0, active = 0; No need to init these two. > + unsigned long flags; > + ktime_t unused; > + > + spin_lock_irqsave(&guc->timestamp.lock, flags); > + > + pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; > + last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); > + engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); > + > + guc_update_pm_timestamp(guc, &unused); > + > + if (engine_id != 0xffffffff && last_switch) { > + start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); > + __extend_last_switch(guc, &start_gt_clk, last_switch); > + active = intel_gt_clock_interval_to_ns(gt, guc->timestamp.gt_stamp - start_gt_clk); > + WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); > + WRITE_ONCE(ce->stats.active, active); > + } else { > + lrc_update_runtime(ce); Why is this called from here? Presumably it was called already from guc_context_unpin if here code things context is not active. Or will be called shortly, once context save is done. Also, some comments here describing the double accounting race would be good. Or if there are some already in the physical engine code just reference that function. Regards, Tvrtko > + } > + > + spin_unlock_irqrestore(&guc->timestamp.lock, flags); > +} > + > +static void guc_context_update_stats(struct intel_context *ce) > +{ > + if (!intel_context_pin_if_active(ce)) { > + WRITE_ONCE(ce->stats.runtime.start_gt_clk, 0); > + WRITE_ONCE(ce->stats.active, 0); > + return; > + } > + > + __guc_context_update_clks(ce); > + intel_context_unpin(ce); > +} > + > static inline bool > submission_disabled(struct intel_guc *guc) > { > @@ -2585,6 +2634,7 @@ static void guc_context_unpin(struct intel_context *ce) > { > struct intel_guc *guc = ce_to_guc(ce); > > + lrc_update_runtime(ce); > unpin_guc_id(guc, ce); > lrc_unpin(ce); > > @@ -3183,6 +3233,7 @@ static void remove_from_context(struct i915_request *rq) > } > > static const struct intel_context_ops guc_context_ops = { > + .flags = COPS_RUNTIME_CYCLES, > .alloc = guc_context_alloc, > > .pre_pin = guc_context_pre_pin, > @@ -3199,6 +3250,8 @@ static const struct intel_context_ops guc_context_ops = { > > .sched_disable = guc_context_sched_disable, > > + .update_stats = guc_context_update_stats, > + > .reset = lrc_reset, > .destroy = guc_context_destroy, > > diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c > index 18d38cb59923..118db6f03f15 100644 > --- a/drivers/gpu/drm/i915/i915_drm_client.c > +++ b/drivers/gpu/drm/i915/i915_drm_client.c > @@ -146,11 +146,7 @@ void i915_drm_client_fdinfo(struct seq_file *m, struct file *f) > PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)); > seq_printf(m, "drm-client-id:\t%u\n", client->id); > > - /* > - * Temporarily skip showing client engine information with GuC submission till > - * fetching engine busyness is implemented in the GuC submission backend > - */ > - if (GRAPHICS_VER(i915) < 8 || intel_uc_uses_guc_submission(&i915->gt0.uc)) > + if (GRAPHICS_VER(i915) < 8) > return; > > for (i = 0; i < ARRAY_SIZE(uabi_class_names); i++)
On Tue, Jun 14, 2022 at 02:30:42PM +0100, Tvrtko Ursulin wrote: > >On 14/06/2022 01:46, Nerlige Ramappa, Umesh wrote: >>From: John Harrison <John.C.Harrison@Intel.com> >> >>GuC provides engine_id and last_switch_in ticks for an active context in the >>pphwsp. The context image provides a 32 bit total ticks which is the accumulated >>by the context (a.k.a. context[CTX_TIMESTAMP]). This information is used to >>calculate the context busyness as follows: >> >>If the engine_id is valid, then busyness is the sum of accumulated total ticks >>and active ticks. Active ticks is calculated with current gt time as reference. >> >>If engine_id is invalid, busyness is equal to accumulated total ticks. >> >>Since KMD (CPU) retrieves busyness data from 2 sources - GPU and GuC, a >>potential race was highlighted in an earlier review that can lead to double >>accounting of busyness. While the solution to this is a wip, busyness is still >>usable for platforms running GuC submission. >> >>Signed-off-by: John Harrison <John.C.Harrison@Intel.com> >>Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> >>--- >> drivers/gpu/drm/i915/gt/intel_context.c | 11 +++- >> drivers/gpu/drm/i915/gt/intel_context.h | 6 +- >> drivers/gpu/drm/i915/gt/intel_context_types.h | 3 + >> drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 5 ++ >> .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 55 ++++++++++++++++++- >> drivers/gpu/drm/i915/i915_drm_client.c | 6 +- >> 6 files changed, 75 insertions(+), 11 deletions(-) >> >>diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c >>index 4070cb5711d8..a49f313db911 100644 >>--- a/drivers/gpu/drm/i915/gt/intel_context.c >>+++ b/drivers/gpu/drm/i915/gt/intel_context.c >>@@ -576,16 +576,23 @@ void intel_context_bind_parent_child(struct intel_context *parent, >> child->parallel.parent = parent; >> } >>-u64 intel_context_get_total_runtime_ns(const struct intel_context *ce) >>+u64 intel_context_get_total_runtime_ns(struct intel_context *ce) >> { >> u64 total, active; >>+ if (ce->ops->update_stats) >>+ ce->ops->update_stats(ce); >>+ >> total = ce->stats.runtime.total; >> if (ce->ops->flags & COPS_RUNTIME_CYCLES) >> total *= ce->engine->gt->clock_period_ns; >> active = READ_ONCE(ce->stats.active); >>- if (active) >>+ /* >>+ * GuC backend returns the actual time the context was active, so skip >>+ * the calculation here for GuC. >>+ */ >>+ if (active && !intel_engine_uses_guc(ce->engine)) > >What is the point of looking at ce->stats.active in GuC mode? I see >that guc_context_update_stats/__guc_context_update_clks touches it, >but I can't spot that there is a purpose to it. This is the only >conditional reading it but it is short-circuited in GuC case. > >Also, since a GuC only vfunc (update_stats) has been added, I wonder >why not just fork the whole runtime query (ce->get_total_runtime_ns). >I think that would end up cleaner. > >> active = intel_context_clock() - active; >> return total + active; In case of GuC the active is used directly here since the active updated in update_stats is equal to the active time of the context already. I will look into separate vfunc. >>diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h >>index b7d3214d2cdd..5fc7c19ab29b 100644 >>--- a/drivers/gpu/drm/i915/gt/intel_context.h >>+++ b/drivers/gpu/drm/i915/gt/intel_context.h >>@@ -56,7 +56,7 @@ static inline bool intel_context_is_parent(struct intel_context *ce) >> return !!ce->parallel.number_children; >> } snip >>+static void __guc_context_update_clks(struct intel_context *ce) >>+{ >>+ struct intel_guc *guc = ce_to_guc(ce); >>+ struct intel_gt *gt = ce->engine->gt; >>+ u32 *pphwsp, last_switch, engine_id; >>+ u64 start_gt_clk = 0, active = 0; > >No need to init these two. > >>+ unsigned long flags; >>+ ktime_t unused; >>+ >>+ spin_lock_irqsave(&guc->timestamp.lock, flags); >>+ >>+ pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; >>+ last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); >>+ engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); >>+ >>+ guc_update_pm_timestamp(guc, &unused); >>+ >>+ if (engine_id != 0xffffffff && last_switch) { >>+ start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); >>+ __extend_last_switch(guc, &start_gt_clk, last_switch); >>+ active = intel_gt_clock_interval_to_ns(gt, guc->timestamp.gt_stamp - start_gt_clk); >>+ WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); >>+ WRITE_ONCE(ce->stats.active, active); >>+ } else { >>+ lrc_update_runtime(ce); > >Why is this called from here? Presumably it was called already from >guc_context_unpin if here code things context is not active. Or will >be called shortly, once context save is done. guc_context_unpin is only called in the path of ce->sched_disable. The sched_disable is implemented in GuC (H2G message). Once the corresponding G2H response is received, the context is actually unpinned, eventually calling guc_context_unpin. Also the context may not necessarily be disabled after each context exit. > >Also, some comments here describing the double accounting race would >be good. Or if there are some already in the physical engine code just >reference that function. Will do, Thanks, Umesh > >Regards, > >Tvrtko >
On 14/06/2022 17:32, Umesh Nerlige Ramappa wrote: > On Tue, Jun 14, 2022 at 02:30:42PM +0100, Tvrtko Ursulin wrote: >> >> On 14/06/2022 01:46, Nerlige Ramappa, Umesh wrote: >>> From: John Harrison <John.C.Harrison@Intel.com> >>> >>> GuC provides engine_id and last_switch_in ticks for an active context >>> in the >>> pphwsp. The context image provides a 32 bit total ticks which is the >>> accumulated >>> by the context (a.k.a. context[CTX_TIMESTAMP]). This information is >>> used to >>> calculate the context busyness as follows: >>> >>> If the engine_id is valid, then busyness is the sum of accumulated >>> total ticks >>> and active ticks. Active ticks is calculated with current gt time as >>> reference. >>> >>> If engine_id is invalid, busyness is equal to accumulated total ticks. >>> >>> Since KMD (CPU) retrieves busyness data from 2 sources - GPU and GuC, a >>> potential race was highlighted in an earlier review that can lead to >>> double >>> accounting of busyness. While the solution to this is a wip, busyness >>> is still >>> usable for platforms running GuC submission. >>> >>> Signed-off-by: John Harrison <John.C.Harrison@Intel.com> >>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> >>> --- >>> drivers/gpu/drm/i915/gt/intel_context.c | 11 +++- >>> drivers/gpu/drm/i915/gt/intel_context.h | 6 +- >>> drivers/gpu/drm/i915/gt/intel_context_types.h | 3 + >>> drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 5 ++ >>> .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 55 ++++++++++++++++++- >>> drivers/gpu/drm/i915/i915_drm_client.c | 6 +- >>> 6 files changed, 75 insertions(+), 11 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/i915/gt/intel_context.c >>> b/drivers/gpu/drm/i915/gt/intel_context.c >>> index 4070cb5711d8..a49f313db911 100644 >>> --- a/drivers/gpu/drm/i915/gt/intel_context.c >>> +++ b/drivers/gpu/drm/i915/gt/intel_context.c >>> @@ -576,16 +576,23 @@ void intel_context_bind_parent_child(struct >>> intel_context *parent, >>> child->parallel.parent = parent; >>> } >>> -u64 intel_context_get_total_runtime_ns(const struct intel_context *ce) >>> +u64 intel_context_get_total_runtime_ns(struct intel_context *ce) >>> { >>> u64 total, active; >>> + if (ce->ops->update_stats) >>> + ce->ops->update_stats(ce); >>> + >>> total = ce->stats.runtime.total; >>> if (ce->ops->flags & COPS_RUNTIME_CYCLES) >>> total *= ce->engine->gt->clock_period_ns; >>> active = READ_ONCE(ce->stats.active); >>> - if (active) >>> + /* >>> + * GuC backend returns the actual time the context was active, >>> so skip >>> + * the calculation here for GuC. >>> + */ >>> + if (active && !intel_engine_uses_guc(ce->engine)) >> >> What is the point of looking at ce->stats.active in GuC mode? I see >> that guc_context_update_stats/__guc_context_update_clks touches it, >> but I can't spot that there is a purpose to it. This is the only >> conditional reading it but it is short-circuited in GuC case. >> >> Also, since a GuC only vfunc (update_stats) has been added, I wonder >> why not just fork the whole runtime query (ce->get_total_runtime_ns). >> I think that would end up cleaner. >> >>> active = intel_context_clock() - active; >>> return total + active; > > In case of GuC the active is used directly here since the active updated > in update_stats is equal to the active time of the context already. I > will look into separate vfunc. Ah right, I misread something. But yes, I think a separate vfunc will look cleaner. Another option (instead of vfunc) is a similar flag to control the express the flavour of active? >>> diff --git a/drivers/gpu/drm/i915/gt/intel_context.h >>> b/drivers/gpu/drm/i915/gt/intel_context.h >>> index b7d3214d2cdd..5fc7c19ab29b 100644 >>> --- a/drivers/gpu/drm/i915/gt/intel_context.h >>> +++ b/drivers/gpu/drm/i915/gt/intel_context.h >>> @@ -56,7 +56,7 @@ static inline bool intel_context_is_parent(struct >>> intel_context *ce) >>> return !!ce->parallel.number_children; >>> } > > snip > >>> +static void __guc_context_update_clks(struct intel_context *ce) >>> +{ >>> + struct intel_guc *guc = ce_to_guc(ce); >>> + struct intel_gt *gt = ce->engine->gt; >>> + u32 *pphwsp, last_switch, engine_id; >>> + u64 start_gt_clk = 0, active = 0; >> >> No need to init these two. >> >>> + unsigned long flags; >>> + ktime_t unused; >>> + >>> + spin_lock_irqsave(&guc->timestamp.lock, flags); >>> + >>> + pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; >>> + last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); >>> + engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); >>> + >>> + guc_update_pm_timestamp(guc, &unused); >>> + >>> + if (engine_id != 0xffffffff && last_switch) { >>> + start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); >>> + __extend_last_switch(guc, &start_gt_clk, last_switch); >>> + active = intel_gt_clock_interval_to_ns(gt, >>> guc->timestamp.gt_stamp - start_gt_clk); >>> + WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); >>> + WRITE_ONCE(ce->stats.active, active); >>> + } else { >>> + lrc_update_runtime(ce); >> >> Why is this called from here? Presumably it was called already from >> guc_context_unpin if here code things context is not active. Or will >> be called shortly, once context save is done. > > guc_context_unpin is only called in the path of ce->sched_disable. The > sched_disable is implemented in GuC (H2G message). Once the > corresponding G2H response is received, the context is actually > unpinned, eventually calling guc_context_unpin. Also the context may not > necessarily be disabled after each context exit. So if I understand correctly, lrc runtime is only updated if someone is reading the busyness and not as part of normal context state transitions? Regards, Tvrtko
On Wed, Jun 15, 2022 at 08:08:40AM +0100, Tvrtko Ursulin wrote: > >On 14/06/2022 17:32, Umesh Nerlige Ramappa wrote: >>On Tue, Jun 14, 2022 at 02:30:42PM +0100, Tvrtko Ursulin wrote: >>> >>>On 14/06/2022 01:46, Nerlige Ramappa, Umesh wrote: >>>>From: John Harrison <John.C.Harrison@Intel.com> >>>> >>>>GuC provides engine_id and last_switch_in ticks for an active >>>>context in the >>>>pphwsp. The context image provides a 32 bit total ticks which is >>>>the accumulated >>>>by the context (a.k.a. context[CTX_TIMESTAMP]). This information >>>>is used to >>>>calculate the context busyness as follows: >>>> >>>>If the engine_id is valid, then busyness is the sum of >>>>accumulated total ticks >>>>and active ticks. Active ticks is calculated with current gt >>>>time as reference. >>>> >>>>If engine_id is invalid, busyness is equal to accumulated total ticks. >>>> >>>>Since KMD (CPU) retrieves busyness data from 2 sources - GPU and GuC, a >>>>potential race was highlighted in an earlier review that can >>>>lead to double >>>>accounting of busyness. While the solution to this is a wip, >>>>busyness is still >>>>usable for platforms running GuC submission. >>>> >>>>Signed-off-by: John Harrison <John.C.Harrison@Intel.com> >>>>Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> >>>>--- >>>> drivers/gpu/drm/i915/gt/intel_context.c | 11 +++- >>>> drivers/gpu/drm/i915/gt/intel_context.h | 6 +- >>>> drivers/gpu/drm/i915/gt/intel_context_types.h | 3 + >>>> drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 5 ++ >>>> .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 55 ++++++++++++++++++- >>>> drivers/gpu/drm/i915/i915_drm_client.c | 6 +- >>>> 6 files changed, 75 insertions(+), 11 deletions(-) >>>> >>>>diff --git a/drivers/gpu/drm/i915/gt/intel_context.c >>>>b/drivers/gpu/drm/i915/gt/intel_context.c >>>>index 4070cb5711d8..a49f313db911 100644 >>>>--- a/drivers/gpu/drm/i915/gt/intel_context.c >>>>+++ b/drivers/gpu/drm/i915/gt/intel_context.c >>>>@@ -576,16 +576,23 @@ void >>>>intel_context_bind_parent_child(struct intel_context *parent, >>>> child->parallel.parent = parent; >>>> } >>>>-u64 intel_context_get_total_runtime_ns(const struct intel_context *ce) >>>>+u64 intel_context_get_total_runtime_ns(struct intel_context *ce) >>>> { >>>> u64 total, active; >>>>+ if (ce->ops->update_stats) >>>>+ ce->ops->update_stats(ce); >>>>+ >>>> total = ce->stats.runtime.total; >>>> if (ce->ops->flags & COPS_RUNTIME_CYCLES) >>>> total *= ce->engine->gt->clock_period_ns; >>>> active = READ_ONCE(ce->stats.active); >>>>- if (active) >>>>+ /* >>>>+ * GuC backend returns the actual time the context was >>>>active, so skip >>>>+ * the calculation here for GuC. >>>>+ */ >>>>+ if (active && !intel_engine_uses_guc(ce->engine)) >>> >>>What is the point of looking at ce->stats.active in GuC mode? I >>>see that guc_context_update_stats/__guc_context_update_clks >>>touches it, but I can't spot that there is a purpose to it. This >>>is the only conditional reading it but it is short-circuited in >>>GuC case. >>> >>>Also, since a GuC only vfunc (update_stats) has been added, I >>>wonder why not just fork the whole runtime query >>>(ce->get_total_runtime_ns). I think that would end up cleaner. >>> >>>> active = intel_context_clock() - active; >>>> return total + active; >> >>In case of GuC the active is used directly here since the active >>updated in update_stats is equal to the active time of the context >>already. I will look into separate vfunc. > >Ah right, I misread something. But yes, I think a separate vfunc will >look cleaner. Another option (instead of vfunc) is a similar flag to >control the express the flavour of active? Flag does sound simpler. The guc context ops can have something like COPS_RUNTIME_ACTIVE_TOTAL that means total active time. > >>>>diff --git a/drivers/gpu/drm/i915/gt/intel_context.h >>>>b/drivers/gpu/drm/i915/gt/intel_context.h >>>>index b7d3214d2cdd..5fc7c19ab29b 100644 >>>>--- a/drivers/gpu/drm/i915/gt/intel_context.h >>>>+++ b/drivers/gpu/drm/i915/gt/intel_context.h >>>>@@ -56,7 +56,7 @@ static inline bool >>>>intel_context_is_parent(struct intel_context *ce) >>>> return !!ce->parallel.number_children; >>>> } >> >>snip >> >>>>+static void __guc_context_update_clks(struct intel_context *ce) >>>>+{ >>>>+ struct intel_guc *guc = ce_to_guc(ce); >>>>+ struct intel_gt *gt = ce->engine->gt; >>>>+ u32 *pphwsp, last_switch, engine_id; >>>>+ u64 start_gt_clk = 0, active = 0; >>> >>>No need to init these two. >>> >>>>+ unsigned long flags; >>>>+ ktime_t unused; >>>>+ >>>>+ spin_lock_irqsave(&guc->timestamp.lock, flags); >>>>+ >>>>+ pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; >>>>+ last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); >>>>+ engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); >>>>+ >>>>+ guc_update_pm_timestamp(guc, &unused); >>>>+ >>>>+ if (engine_id != 0xffffffff && last_switch) { >>>>+ start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); >>>>+ __extend_last_switch(guc, &start_gt_clk, last_switch); >>>>+ active = intel_gt_clock_interval_to_ns(gt, >>>>guc->timestamp.gt_stamp - start_gt_clk); >>>>+ WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); >>>>+ WRITE_ONCE(ce->stats.active, active); >>>>+ } else { >>>>+ lrc_update_runtime(ce); >>> >>>Why is this called from here? Presumably it was called already >>>from guc_context_unpin if here code things context is not active. >>>Or will be called shortly, once context save is done. >> >>guc_context_unpin is only called in the path of ce->sched_disable. >>The sched_disable is implemented in GuC (H2G message). Once the >>corresponding G2H response is received, the context is actually >>unpinned, eventually calling guc_context_unpin. Also the context may >>not necessarily be disabled after each context exit. > >So if I understand correctly, lrc runtime is only updated if someone >is reading the busyness and not as part of normal context state >transitions? If you mean context_in/out events (like csb interrupts), only GuC can see those events. KMD has no visibility into that. These 3 paths call lrc_update_runtime. user query: (engine_id != 0xffffffff && last_switch) translates to GuC being within context_in and context_out events, so updating it outside of this window is one way to report the correct busyness. worker: guc_timestamp_ping() also updates context stats (infrequently) for all contexts primarily to take care of overflows. context unpin: Existing code calls lrc_update_runtime only when unpinning the context which takes care of accumulating busyness when requests are retired. Thanks, Umesh > >Regards, > >Tvrtko
On Wed, 15 Jun 2022 10:42:08 -0700, Umesh Nerlige Ramappa wrote: > > >>>> +static void __guc_context_update_clks(struct intel_context *ce) > >>>> +{ > >>>> + struct intel_guc *guc = ce_to_guc(ce); > >>>> + struct intel_gt *gt = ce->engine->gt; > >>>> + u32 *pphwsp, last_switch, engine_id; > >>>> + u64 start_gt_clk = 0, active = 0; > >>> > >>> No need to init these two. > >>> > >>>> + unsigned long flags; > >>>> + ktime_t unused; > >>>> + > >>>> + spin_lock_irqsave(&guc->timestamp.lock, flags); > >>>> + > >>>> + pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; > >>>> + last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); > >>>> + engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); > >>>> + > >>>> + guc_update_pm_timestamp(guc, &unused); > >>>> + > >>>> + if (engine_id != 0xffffffff && last_switch) { > >>>> + start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); > >>>> + __extend_last_switch(guc, &start_gt_clk, last_switch); > >>>> + active = intel_gt_clock_interval_to_ns(gt, > >>>> guc->timestamp.gt_stamp - start_gt_clk); > >>>> + WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); > >>>> + WRITE_ONCE(ce->stats.active, active); > >>>> + } else { > >>>> + lrc_update_runtime(ce); > >>> > >>> Why is this called from here? Presumably it was called already from > >>> guc_context_unpin if here code things context is not active. Or will be > >>> called shortly, once context save is done. > >> > >> guc_context_unpin is only called in the path of ce->sched_disable. The > >> sched_disable is implemented in GuC (H2G message). Once the > >> corresponding G2H response is received, the context is actually > >> unpinned, eventually calling guc_context_unpin. Also the context may not > >> necessarily be disabled after each context exit. > > > > So if I understand correctly, lrc runtime is only updated if someone is > > reading the busyness and not as part of normal context state transitions? > > If you mean context_in/out events (like csb interrupts), only GuC can see > those events. KMD has no visibility into that. These 3 paths call > lrc_update_runtime. > > user query: (engine_id != 0xffffffff && last_switch) translates to GuC > being within context_in and context_out events, so updating it outside of > this window is one way to report the correct busyness. > > worker: guc_timestamp_ping() also updates context stats (infrequently) for > all contexts primarily to take care of overflows. > > context unpin: Existing code calls lrc_update_runtime only when unpinning > the context which takes care of accumulating busyness when requests are > retired. Will adding lrc_update_runtime() to lrc_unpin() work?
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index 4070cb5711d8..a49f313db911 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -576,16 +576,23 @@ void intel_context_bind_parent_child(struct intel_context *parent, child->parallel.parent = parent; } -u64 intel_context_get_total_runtime_ns(const struct intel_context *ce) +u64 intel_context_get_total_runtime_ns(struct intel_context *ce) { u64 total, active; + if (ce->ops->update_stats) + ce->ops->update_stats(ce); + total = ce->stats.runtime.total; if (ce->ops->flags & COPS_RUNTIME_CYCLES) total *= ce->engine->gt->clock_period_ns; active = READ_ONCE(ce->stats.active); - if (active) + /* + * GuC backend returns the actual time the context was active, so skip + * the calculation here for GuC. + */ + if (active && !intel_engine_uses_guc(ce->engine)) active = intel_context_clock() - active; return total + active; diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index b7d3214d2cdd..5fc7c19ab29b 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -56,7 +56,7 @@ static inline bool intel_context_is_parent(struct intel_context *ce) return !!ce->parallel.number_children; } -static inline bool intel_context_is_pinned(struct intel_context *ce); +static inline bool intel_context_is_pinned(const struct intel_context *ce); static inline struct intel_context * intel_context_to_parent(struct intel_context *ce) @@ -116,7 +116,7 @@ static inline int intel_context_lock_pinned(struct intel_context *ce) * Returns: true if the context is currently pinned for use by the GPU. */ static inline bool -intel_context_is_pinned(struct intel_context *ce) +intel_context_is_pinned(const struct intel_context *ce) { return atomic_read(&ce->pin_count); } @@ -351,7 +351,7 @@ intel_context_clear_nopreempt(struct intel_context *ce) clear_bit(CONTEXT_NOPREEMPT, &ce->flags); } -u64 intel_context_get_total_runtime_ns(const struct intel_context *ce); +u64 intel_context_get_total_runtime_ns(struct intel_context *ce); u64 intel_context_get_avg_runtime_ns(struct intel_context *ce); static inline u64 intel_context_clock(void) diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index 09f82545789f..0a3290c99a31 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -55,6 +55,8 @@ struct intel_context_ops { void (*sched_disable)(struct intel_context *ce); + void (*update_stats)(struct intel_context *ce); + void (*reset)(struct intel_context *ce); void (*destroy)(struct kref *kref); @@ -146,6 +148,7 @@ struct intel_context { struct ewma_runtime avg; u64 total; u32 last; + u64 start_gt_clk; I915_SELFTEST_DECLARE(u32 num_underflow); I915_SELFTEST_DECLARE(u32 max_underflow); } runtime; diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h index b3c9a9327f76..6231ad03e4eb 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h @@ -196,6 +196,11 @@ static inline u8 guc_class_to_engine_class(u8 guc_class) return guc_class_engine_class_map[guc_class]; } +/* Per context engine usage stats: */ +#define PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO (0x500 / sizeof(u32)) +#define PPHWSP_GUC_CONTEXT_USAGE_STAMP_HI (PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO + 1) +#define PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID (PPHWSP_GUC_CONTEXT_USAGE_STAMP_HI + 1) + /* Work item for submitting workloads into work queue of GuC. */ struct guc_wq_item { u32 header; 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 5a1dfacf24ea..b86401144417 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -378,7 +378,7 @@ static inline void set_context_guc_id_invalid(struct intel_context *ce) ce->guc_id.id = GUC_INVALID_CONTEXT_ID; } -static inline struct intel_guc *ce_to_guc(struct intel_context *ce) +static inline struct intel_guc *ce_to_guc(const struct intel_context *ce) { return &ce->engine->gt->uc.guc; } @@ -1323,13 +1323,16 @@ static void __update_guc_busyness_stats(struct intel_guc *guc) spin_unlock_irqrestore(&guc->timestamp.lock, flags); } +static void __guc_context_update_clks(struct intel_context *ce); static void guc_timestamp_ping(struct work_struct *wrk) { struct intel_guc *guc = container_of(wrk, typeof(*guc), timestamp.work.work); struct intel_uc *uc = container_of(guc, typeof(*uc), guc); struct intel_gt *gt = guc_to_gt(guc); + struct intel_context *ce; intel_wakeref_t wakeref; + unsigned long index; int srcu, ret; /* @@ -1343,6 +1346,10 @@ static void guc_timestamp_ping(struct work_struct *wrk) with_intel_runtime_pm(>->i915->runtime_pm, wakeref) __update_guc_busyness_stats(guc); + /* adjust context stats for overflow */ + xa_for_each(&guc->context_lookup, index, ce) + __guc_context_update_clks(ce); + intel_gt_reset_unlock(gt, srcu); mod_delayed_work(system_highpri_wq, &guc->timestamp.work, @@ -1405,6 +1412,48 @@ void intel_guc_busyness_unpark(struct intel_gt *gt) guc->timestamp.ping_delay); } +static void __guc_context_update_clks(struct intel_context *ce) +{ + struct intel_guc *guc = ce_to_guc(ce); + struct intel_gt *gt = ce->engine->gt; + u32 *pphwsp, last_switch, engine_id; + u64 start_gt_clk = 0, active = 0; + unsigned long flags; + ktime_t unused; + + spin_lock_irqsave(&guc->timestamp.lock, flags); + + pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; + last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]); + engine_id = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_ENGINE_ID]); + + guc_update_pm_timestamp(guc, &unused); + + if (engine_id != 0xffffffff && last_switch) { + start_gt_clk = READ_ONCE(ce->stats.runtime.start_gt_clk); + __extend_last_switch(guc, &start_gt_clk, last_switch); + active = intel_gt_clock_interval_to_ns(gt, guc->timestamp.gt_stamp - start_gt_clk); + WRITE_ONCE(ce->stats.runtime.start_gt_clk, start_gt_clk); + WRITE_ONCE(ce->stats.active, active); + } else { + lrc_update_runtime(ce); + } + + spin_unlock_irqrestore(&guc->timestamp.lock, flags); +} + +static void guc_context_update_stats(struct intel_context *ce) +{ + if (!intel_context_pin_if_active(ce)) { + WRITE_ONCE(ce->stats.runtime.start_gt_clk, 0); + WRITE_ONCE(ce->stats.active, 0); + return; + } + + __guc_context_update_clks(ce); + intel_context_unpin(ce); +} + static inline bool submission_disabled(struct intel_guc *guc) { @@ -2585,6 +2634,7 @@ static void guc_context_unpin(struct intel_context *ce) { struct intel_guc *guc = ce_to_guc(ce); + lrc_update_runtime(ce); unpin_guc_id(guc, ce); lrc_unpin(ce); @@ -3183,6 +3233,7 @@ static void remove_from_context(struct i915_request *rq) } static const struct intel_context_ops guc_context_ops = { + .flags = COPS_RUNTIME_CYCLES, .alloc = guc_context_alloc, .pre_pin = guc_context_pre_pin, @@ -3199,6 +3250,8 @@ static const struct intel_context_ops guc_context_ops = { .sched_disable = guc_context_sched_disable, + .update_stats = guc_context_update_stats, + .reset = lrc_reset, .destroy = guc_context_destroy, diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c index 18d38cb59923..118db6f03f15 100644 --- a/drivers/gpu/drm/i915/i915_drm_client.c +++ b/drivers/gpu/drm/i915/i915_drm_client.c @@ -146,11 +146,7 @@ void i915_drm_client_fdinfo(struct seq_file *m, struct file *f) PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)); seq_printf(m, "drm-client-id:\t%u\n", client->id); - /* - * Temporarily skip showing client engine information with GuC submission till - * fetching engine busyness is implemented in the GuC submission backend - */ - if (GRAPHICS_VER(i915) < 8 || intel_uc_uses_guc_submission(&i915->gt0.uc)) + if (GRAPHICS_VER(i915) < 8) return; for (i = 0; i < ARRAY_SIZE(uabi_class_names); i++)