On Fri, Aug 05, 2022 at 10:45:30AM +0100, Tvrtko Ursulin wrote:
On 05/08/2022 00:21, Umesh Nerlige Ramappa wrote:From: John Harrison <John.C.Harrison@xxxxxxxxx> 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. Remaining work: Enable and test context busyness for virtual_parent_context_ops and virtual_child_context_ops.I meant track the IGT work in the jira internally. :)
Oh, I did do that and added this here as well. Note that I have not enabled the busyness in i915 for the parent/child context ops since I was not able to verify it yet.
Otherwise: Acked-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>Also, can someone else please do the full review? I'm afraid with the passage of time I forgot what little I knew about how GuC tracks this data. :(
I will ask around
Some nits and questions below.v2: (Tvrtko) - Use COPS_RUNTIME_ACTIVE_TOTAL - Add code comment for the race - Undo local variables initializations v3: - Add support for virtual engines based on https://patchwork.freedesktop.org/series/105227/ v4: - Update commit message with remaining work. - Rebase Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_context.c | 12 +++- drivers/gpu/drm/i915/gt/intel_context.h | 6 +- drivers/gpu/drm/i915/gt/intel_context_types.h | 6 ++ drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 5 ++ .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 65 ++++++++++++++++++- drivers/gpu/drm/i915/i915_drm_client.c | 6 +- 6 files changed, 89 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index 654a092ed3d6..e2d70a9fdac0 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -576,16 +576,24 @@ 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) + /* + * When COPS_RUNTIME_ACTIVE_TOTAL is set for ce->cops, the backend + * already provides the total active time of the context, so skip this + * calculation when this flag is set. + */ + if (active && !(ce->ops->flags & COPS_RUNTIME_ACTIVE_TOTAL)) 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 8e2d70630c49..3d1d7436c1a4 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -58,7 +58,7 @@ 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) @@ -118,7 +118,7 @@ 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); } @@ -362,7 +362,7 @@ 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 04eacae1aca5..f7ff4c7d81c7 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -38,6 +38,9 @@ struct intel_context_ops { #define COPS_RUNTIME_CYCLES_BIT 1 #define COPS_RUNTIME_CYCLES BIT(COPS_RUNTIME_CYCLES_BIT) +#define COPS_RUNTIME_ACTIVE_TOTAL_BIT 2 +#define COPS_RUNTIME_ACTIVE_TOTAL BIT(COPS_RUNTIME_ACTIVE_TOTAL_BIT) + int (*alloc)(struct intel_context *ce); void (*revoke)(struct intel_context *ce, struct i915_request *rq, @@ -56,6 +59,8 @@ 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); @@ -148,6 +153,7 @@ struct intel_context { struct ewma_runtime avg; u64 total; u32 last; + u64 start_gt_clk;Nit - put u64 next to u64 and u32 next to u32 to avoid holes.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 323b055e5db9..c7b54f1631b9 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 0d17da77e787..c9fefa254a7e 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)This is odd since the helper now takes away constness. I can't really figure out why the change is needed?{ return &ce->engine->gt->uc.guc; } @@ -1376,13 +1376,16 @@ 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; /* @@ -1396,6 +1399,10 @@ 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, @@ -1469,6 +1476,56 @@ 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, active; + unsigned long flags; + ktime_t unused; + + spin_lock_irqsave(&guc->timestamp.lock, flags); + + /* + * GPU updates ce->lrc_reg_state[CTX_TIMESTAMP] when context is switched + * out, however GuC updates PPHWSP offsets below. Hence KMD (CPU) + * relies on GuC and GPU for busyness calculations. Due to this, 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. + */ + pphwsp = ((void *)ce->lrc_reg_state) - LRC_STATE_OFFSET; + last_switch = READ_ONCE(pphwsp[PPHWSP_GUC_CONTEXT_USAGE_STAMP_LO]);What about PPHWSP_GUC_CONTEXT_USAGE_STAMP_HI? I see it defined but isn't used so is the timestmap 32 bit just ABI reserved 64 bits for future proofing or something?
Yes, the _HI is not populated by GuC yet, but reserved for future extension to 64 bits.
Thanks, Umesh
Regards, Tvrtko+ 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) { @@ -2723,6 +2780,7 @@ 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); @@ -3344,6 +3402,7 @@ static void remove_from_context(struct i915_request *rq) } static const struct intel_context_ops guc_context_ops = { + .flags = COPS_RUNTIME_CYCLES | COPS_RUNTIME_ACTIVE_TOTAL, .alloc = guc_context_alloc, .pre_pin = guc_context_pre_pin, @@ -3360,6 +3419,8 @@ 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, @@ -3593,6 +3654,7 @@ static int guc_virtual_context_alloc(struct intel_context *ce) } static const struct intel_context_ops virtual_guc_context_ops = { + .flags = COPS_RUNTIME_CYCLES | COPS_RUNTIME_ACTIVE_TOTAL, .alloc = guc_virtual_context_alloc, .pre_pin = guc_virtual_context_pre_pin, @@ -3608,6 +3670,7 @@ static const struct intel_context_ops virtual_guc_context_ops = { .exit = guc_virtual_context_exit, .sched_disable = guc_context_sched_disable, + .update_stats = guc_context_update_stats, .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 b09d1d386574..8d81119fff14 100644 --- a/drivers/gpu/drm/i915/i915_drm_client.c +++ b/drivers/gpu/drm/i915/i915_drm_client.c @@ -147,11 +147,7 @@ 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++)
