[PATCH] drm/i915: Track hw reported context runtime
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Tue Feb 4 17:31:54 UTC 2020
From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
GPU saves accumulated context runtime (in CS timestamp units) in PPHWSP
which will be useful for us in cases when we are not able to track context
busyness ourselves (like with GuC). Keep a copy of this in struct
intel_context from where it can be easily read even if the context is not
pinned.
QQQ: Do we want to make this accounting conditional / able to turn on/off?
v2:
(Chris)
* Do not store pphwsp address in intel_context.
* Log CS wrap-around.
* Simplify calculation by relying on integer wraparound.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
drivers/gpu/drm/i915/gt/intel_context.h | 7 ++
drivers/gpu/drm/i915/gt/intel_context_types.h | 6 ++
drivers/gpu/drm/i915/gt/intel_lrc.c | 31 ++++++-
drivers/gpu/drm/i915/gt/selftest_lrc.c | 90 +++++++++++++++++++
drivers/gpu/drm/i915/intel_device_info.c | 6 ++
drivers/gpu/drm/i915/intel_device_info.h | 1 +
6 files changed, 140 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index 604d5cfc46ba..c85e10b63fbd 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include "i915_active.h"
+#include "i915_drv.h"
#include "intel_context_types.h"
#include "intel_engine_types.h"
#include "intel_ring_types.h"
@@ -227,4 +228,10 @@ intel_context_clear_nopreempt(struct intel_context *ce)
clear_bit(CONTEXT_NOPREEMPT, &ce->flags);
}
+static inline u64 intel_context_get_hw_runtime_ns(struct intel_context *ce)
+{
+ return ce->total_runtime *
+ RUNTIME_INFO(ce->engine->i915)->cs_timestamp_period_ns;
+}
+
#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 ca1420fb8b53..7821d486d428 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -68,6 +68,12 @@ struct intel_context {
u64 lrc_desc;
u32 tag; /* cookie passed to HW to track this context on submission */
+ /* Time on GPU as tracked by the hw. */
+ u32 last_runtime;
+ u64 total_runtime;
+ ktime_t last_runtime_update;
+ I915_SELFTEST_DECLARE(unsigned long runtime_underflow);
+
unsigned int active_count; /* protected by timeline->mutex */
atomic_t pin_count;
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index c196fb90c59f..5859a511e8ea 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1260,11 +1260,36 @@ static void kick_siblings(struct i915_request *rq, struct intel_context *ce)
tasklet_schedule(&ve->base.execlists.tasklet);
}
+static u32 intel_context_get_runtime(struct intel_context *ce)
+{
+ /*
+ * PPHWSP is one page before the lrc state page and in it at
+ * dword 16 we have cumulative context runtime in CS timestamp ticks.
+ */
+ BUILD_BUG_ON((LRC_STATE_PN - LRC_PPHWSP_PN) != 1);
+ return ce->lrc_reg_state[-1024 + 16];
+}
+
+static void intel_context_update_runtime(struct intel_context *ce)
+{
+ u32 new, old;
+
+ old = ce->last_runtime;
+ new = intel_context_get_runtime(ce);
+ ce->last_runtime_update = ktime_get();
+ if (I915_SELFTEST_ONLY(new < old)) {
+ I915_SELFTEST_ONLY(ce->runtime_underflow++);
+ drm_info(&ce->engine->i915->drm, "%p old=%u new=%u\n", ce, old, new);
+ }
+ ce->last_runtime = new;
+ ce->total_runtime += new - old;
+}
+
static inline void
__execlists_schedule_out(struct i915_request *rq,
struct intel_engine_cs * const engine)
{
- 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
@@ -1284,6 +1309,8 @@ __execlists_schedule_out(struct i915_request *rq,
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
intel_gt_pm_put_async(engine->gt);
+ intel_context_update_runtime(ce);
+
/*
* If this is part of a virtual engine, its next request may
* have been blocked waiting for access to the active context.
@@ -2864,6 +2891,7 @@ static void execlists_context_unpin(struct intel_context *ce)
check_redzone((void *)ce->lrc_reg_state - LRC_STATE_PN * PAGE_SIZE,
ce->engine);
+ intel_context_update_runtime(ce);
i915_gem_object_unpin_map(ce->state->obj);
}
@@ -2908,6 +2936,7 @@ __execlists_context_pin(struct intel_context *ce,
ce->lrc_desc = lrc_descriptor(ce, engine) | CTX_DESC_FORCE_RESTORE;
ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE;
__execlists_update_reg_state(ce, engine);
+ intel_context_update_runtime(ce);
return 0;
}
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 79b9f7d092e4..c957ab81e34b 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -4263,6 +4263,95 @@ static int live_gpr_clear(void *arg)
return err;
}
+static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+ struct i915_request *rq;
+ IGT_TIMEOUT(end_time);
+ bool timeout = false;
+ int err;
+
+ ce = intel_context_create(engine);
+ if (IS_ERR(ce))
+ return PTR_ERR(ce);
+
+ engine->kernel_context->runtime_underflow = 0;
+ ce->runtime_underflow = 0;
+
+ while (!timeout) {
+ unsigned int loop = 1024;
+
+ while (loop) {
+ rq = intel_context_create_request(ce);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto err_rq;
+ }
+
+ if (--loop == 0)
+ i915_request_get(rq);
+
+ i915_request_add(rq);
+ }
+ timeout = __igt_timeout(end_time, NULL);
+ if (!timeout)
+ i915_request_put(rq);
+ }
+
+ err = i915_request_wait(rq, 0, HZ / 5);
+ if (err < 0) {
+ pr_err("%s: request not completed! (err=%d)\n",
+ engine->name, err);
+ goto err_wait;
+ }
+
+ igt_flush_test(engine->i915);
+
+ err = 0;
+ if (ce->runtime_underflow) {
+// err = -EOVERFLOW;
+ pr_info("%s: pphwsp underflow %lu time(s)!\n",
+ engine->name, ce->runtime_underflow);
+ }
+
+ if (engine->kernel_context->runtime_underflow) {
+// err = -EOVERFLOW;
+ pr_info("%s: pphwsp kernel context underflow %lu time(s)!\n",
+ engine->name, engine->kernel_context->runtime_underflow);
+ }
+
+err_wait:
+ i915_request_put(rq);
+err_rq:
+ intel_context_put(ce);
+
+ return err;
+}
+
+static int live_pphwsp_runtime(void *arg)
+{
+ struct intel_gt *gt = arg;
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ int err = 0;
+
+ /*
+ * Check that cumulative context runtime as stored in the pphwsp[16]
+ * is monotonic.
+ */
+
+ for_each_engine(engine, gt, id) {
+ err = __live_pphwsp_runtime(engine);
+ if (err)
+ break;
+ }
+
+ if (igt_flush_test(gt->i915))
+ err = -EIO;
+
+ return err;
+}
+
int intel_lrc_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
@@ -4270,6 +4359,7 @@ int intel_lrc_live_selftests(struct drm_i915_private *i915)
SUBTEST(live_lrc_fixed),
SUBTEST(live_lrc_state),
SUBTEST(live_gpr_clear),
+ SUBTEST(live_pphwsp_runtime),
};
if (!HAS_LOGICAL_RING_CONTEXTS(i915))
diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index fcdacd6d4aa5..552060152a1b 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -1045,6 +1045,12 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
/* Initialize command stream timestamp frequency */
runtime->cs_timestamp_frequency_khz = read_timestamp_frequency(dev_priv);
+ runtime->cs_timestamp_period_ns =
+ div_u64(1e6, runtime->cs_timestamp_frequency_khz);
+ drm_dbg(&dev_priv->drm,
+ "CS timestamp wraparound in %lldms\n",
+ div_u64((u64)runtime->cs_timestamp_period_ns * U32_MAX,
+ USEC_PER_SEC));
}
void intel_driver_caps_print(const struct intel_driver_caps *caps,
diff --git a/drivers/gpu/drm/i915/intel_device_info.h b/drivers/gpu/drm/i915/intel_device_info.h
index 2725cb7fc169..9ec816dbc418 100644
--- a/drivers/gpu/drm/i915/intel_device_info.h
+++ b/drivers/gpu/drm/i915/intel_device_info.h
@@ -216,6 +216,7 @@ struct intel_runtime_info {
struct sseu_dev_info sseu;
u32 cs_timestamp_frequency_khz;
+ u32 cs_timestamp_period_ns;
/* Media engine access to SFC per instance */
u8 vdbox_sfc_access;
--
2.20.1
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