[Intel-gfx] [PATCH 8/9] drm/i915: Track context current active time
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Fri Sep 4 12:59:33 UTC 2020
From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Track context active (on hardware) status together with the start
timestamp.
This will be used to provide better granularity of context
runtime reporting in conjunction with already tracked pphwsp accumulated
runtime.
The latter is only updated on context save so does not give us visibility
to any currently executing work.
As part of the patch the existing runtime tracking data is moved under the
new ce->stats member and updated under the seqlock. This provides the
ability to atomically read out accumulated plus active runtime.
v2:
* Rename and make __intel_context_get_active_time unlocked.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 3 +-
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 | 24 +++++---
drivers/gpu/drm/i915/gt/intel_lrc.c | 57 ++++++++++++++-----
drivers/gpu/drm/i915/gt/selftest_lrc.c | 10 ++--
drivers/gpu/drm/i915/i915_drm_client.c | 2 +-
drivers/gpu/drm/i915/i915_gpu_error.c | 4 +-
8 files changed, 84 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index f9b11e4cc3ad..5944d5808610 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -262,7 +262,8 @@ static void free_engines_rcu(struct rcu_head *rcu)
unsigned int class = ce->engine->uabi_class;
GEM_BUG_ON(class >= ARRAY_SIZE(ctx->past_runtime));
- atomic64_add(ce->runtime.total, &ctx->past_runtime[class]);
+ atomic64_add(ce->stats.runtime.total,
+ &ctx->past_runtime[class]);
}
i915_gem_context_put(ctx);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index d301dda1b261..471550e60a35 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -369,7 +369,7 @@ intel_context_init(struct intel_context *ce,
ce->sseu = engine->sseu;
ce->ring = __intel_context_ring_size(SZ_4K);
- ewma_runtime_init(&ce->runtime.avg);
+ ewma_runtime_init(&ce->stats.runtime.avg);
ce->vm = i915_vm_get(engine->gt->vm);
@@ -377,6 +377,7 @@ intel_context_init(struct intel_context *ce,
INIT_LIST_HEAD(&ce->signals);
mutex_init(&ce->pin_mutex);
+ seqlock_init(&ce->stats.lock);
i915_active_init(&ce->active,
__intel_context_active, __intel_context_retire);
@@ -493,6 +494,14 @@ struct i915_request *intel_context_create_request(struct intel_context *ce)
return rq;
}
+ktime_t __intel_context_get_active_time(struct intel_context *ce)
+{
+ struct intel_context_stats *stats = &ce->stats;
+
+ return stats->active ? ktime_sub(ktime_get(), stats->start) : 0;
+}
+
+
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftest_context.c"
#endif
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index fda2eba81e22..1e76291485ac 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -251,7 +251,7 @@ static inline u64 intel_context_get_total_runtime_ns(struct intel_context *ce)
const u32 period =
RUNTIME_INFO(ce->engine->i915)->cs_timestamp_period_ns;
- return READ_ONCE(ce->runtime.total) * period;
+ return READ_ONCE(ce->stats.runtime.total) * period;
}
static inline u64 intel_context_get_avg_runtime_ns(struct intel_context *ce)
@@ -259,7 +259,9 @@ static inline u64 intel_context_get_avg_runtime_ns(struct intel_context *ce)
const u32 period =
RUNTIME_INFO(ce->engine->i915)->cs_timestamp_period_ns;
- return mul_u32_u32(ewma_runtime_read(&ce->runtime.avg), period);
+ return mul_u32_u32(ewma_runtime_read(&ce->stats.runtime.avg), period);
}
+ktime_t __intel_context_get_active_time(struct intel_context *ce);
+
#endif /* __INTEL_CONTEXT_H__ */
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 552cb57a2e8c..bdeb65c0f1a9 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -12,6 +12,7 @@
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/types.h>
+#include <linux/seqlock.h>
#include "i915_active_types.h"
#include "i915_utils.h"
@@ -81,14 +82,21 @@ struct intel_context {
} lrc;
u32 tag; /* cookie passed to HW to track this context on submission */
- /* Time on GPU as tracked by the hw. */
- struct {
- struct ewma_runtime avg;
- u64 total;
- u32 last;
- I915_SELFTEST_DECLARE(u32 num_underflow);
- I915_SELFTEST_DECLARE(u32 max_underflow);
- } runtime;
+ /** stats: Context GPU engine busyness tracking. */
+ struct intel_context_stats {
+ seqlock_t lock;
+ bool active;
+ ktime_t start;
+
+ /* Time on GPU as tracked by the hw. */
+ struct {
+ struct ewma_runtime avg;
+ u64 total;
+ u32 last;
+ I915_SELFTEST_DECLARE(u32 num_underflow);
+ I915_SELFTEST_DECLARE(u32 max_underflow);
+ } runtime;
+ } stats;
unsigned int active_count; /* protected by timeline->mutex */
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 0412a44f25f2..9ce123450f1e 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1262,7 +1262,7 @@ static void restore_default_state(struct intel_context *ce,
regs = memset(ce->lrc_reg_state, 0, engine->context_size - PAGE_SIZE);
execlists_init_reg_state(regs, ce, engine, ce->ring, true);
- ce->runtime.last = intel_context_get_runtime(ce);
+ ce->stats.runtime.last = intel_context_get_runtime(ce);
}
static void reset_active(struct i915_request *rq,
@@ -1304,35 +1304,61 @@ static void reset_active(struct i915_request *rq,
ce->lrc.desc |= CTX_DESC_FORCE_RESTORE;
}
-static void st_update_runtime_underflow(struct intel_context *ce, s32 dt)
+static void
+st_update_runtime_underflow(struct intel_context_stats *stats, s32 dt)
{
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
- ce->runtime.num_underflow += dt < 0;
- ce->runtime.max_underflow = max_t(u32, ce->runtime.max_underflow, -dt);
+ stats->runtime.num_underflow += dt < 0;
+ stats->runtime.max_underflow =
+ max_t(u32, stats->runtime.max_underflow, -dt);
#endif
}
static void intel_context_update_runtime(struct intel_context *ce)
{
+ struct intel_context_stats *stats = &ce->stats;
u32 old;
s32 dt;
if (intel_context_is_barrier(ce))
return;
- old = ce->runtime.last;
- ce->runtime.last = intel_context_get_runtime(ce);
- dt = ce->runtime.last - old;
+ old = stats->runtime.last;
+ stats->runtime.last = intel_context_get_runtime(ce);
+ dt = stats->runtime.last - old;
if (unlikely(dt <= 0)) {
CE_TRACE(ce, "runtime underflow: last=%u, new=%u, delta=%d\n",
- old, ce->runtime.last, dt);
- st_update_runtime_underflow(ce, dt);
+ old, stats->runtime.last, dt);
+ st_update_runtime_underflow(stats, dt);
return;
}
- ewma_runtime_add(&ce->runtime.avg, dt);
- ce->runtime.total += dt;
+ ewma_runtime_add(&stats->runtime.avg, dt);
+ stats->runtime.total += dt;
+}
+
+static void intel_context_stats_start(struct intel_context *ce)
+{
+ struct intel_context_stats *stats = &ce->stats;
+ unsigned long flags;
+
+ write_seqlock_irqsave(&stats->lock, flags);
+ stats->start = ktime_get();
+ stats->active = true;
+ write_sequnlock_irqrestore(&stats->lock, flags);
+}
+
+static void intel_context_stats_stop(struct intel_context *ce)
+{
+ struct intel_context_stats *stats = &ce->stats;
+ unsigned long flags;
+
+ write_seqlock_irqsave(&stats->lock, flags);
+ stats->active = false;
+ stats->start = 0;
+ intel_context_update_runtime(ce);
+ write_sequnlock_irqrestore(&stats->lock, flags);
}
static inline struct intel_engine_cs *
@@ -1410,7 +1436,7 @@ __execlists_schedule_out(struct i915_request *rq,
struct intel_engine_cs * const engine,
unsigned int ccid)
{
- struct intel_context * const ce = rq->context;
+ struct intel_context *ce = rq->context;
/*
* NB process_csb() is not under the engine->active.lock and hence
@@ -1436,6 +1462,7 @@ __execlists_schedule_out(struct i915_request *rq,
intel_context_update_runtime(ce);
intel_engine_context_out(engine);
+ intel_context_stats_stop(ce);
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
if (engine->fw_domain && !atomic_dec_return(&engine->fw_active))
intel_uncore_forcewake_put(engine->uncore, engine->fw_domain);
@@ -1995,15 +2022,19 @@ static unsigned long active_timeslice(const struct intel_engine_cs *engine)
static void set_timeslice(struct intel_engine_cs *engine)
{
+ struct intel_engine_execlists * const execlists = &engine->execlists;
unsigned long duration;
+ if (*execlists->active)
+ intel_context_stats_start((*execlists->active)->context);
+
if (!intel_engine_has_timeslices(engine))
return;
duration = active_timeslice(engine);
ENGINE_TRACE(engine, "bump timeslicing, interval:%lu", duration);
- set_timer_ms(&engine->execlists.timer, duration);
+ set_timer_ms(&execlists->timer, duration);
}
static void start_timeslice(struct intel_engine_cs *engine, int prio)
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 95d41c01d0e0..67f8083f40a3 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -6381,8 +6381,8 @@ static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
if (IS_ERR(ce))
return PTR_ERR(ce);
- ce->runtime.num_underflow = 0;
- ce->runtime.max_underflow = 0;
+ ce->stats.runtime.num_underflow = 0;
+ ce->stats.runtime.max_underflow = 0;
do {
unsigned int loop = 1024;
@@ -6420,11 +6420,11 @@ static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
intel_context_get_avg_runtime_ns(ce));
err = 0;
- if (ce->runtime.num_underflow) {
+ if (ce->stats.runtime.num_underflow) {
pr_err("%s: pphwsp underflow %u time(s), max %u cycles!\n",
engine->name,
- ce->runtime.num_underflow,
- ce->runtime.max_underflow);
+ ce->stats.runtime.num_underflow,
+ ce->stats.runtime.max_underflow);
GEM_TRACE_DUMP();
err = -EOVERFLOW;
}
diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
index 55241702bea8..02cca05d75bf 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.c
+++ b/drivers/gpu/drm/i915/i915_drm_client.c
@@ -68,7 +68,7 @@ pphwsp_busy_add(struct i915_gem_context *ctx, unsigned int class)
for_each_gem_engine(ce, engines, it) {
if (ce->engine->uabi_class == class)
- total += ce->runtime.total;
+ total += ce->stats.runtime.total;
}
return total;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 8e468942f943..4262a2c72617 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1277,8 +1277,8 @@ static bool record_context(struct i915_gem_context_coredump *e,
e->guilty = atomic_read(&ctx->guilty_count);
e->active = atomic_read(&ctx->active_count);
- e->total_runtime = rq->context->runtime.total;
- e->avg_runtime = ewma_runtime_read(&rq->context->runtime.avg);
+ e->total_runtime = rq->context->stats.runtime.total;
+ e->avg_runtime = ewma_runtime_read(&rq->context->stats.runtime.avg);
simulated = i915_gem_context_no_error_capture(ctx);
--
2.25.1
More information about the Intel-gfx
mailing list