Commit dee4a0f8 authored by Chris Wilson's avatar Chris Wilson

drm/i915/selftests: Smoketest preemption

Very light stress test to bombard the submission backends with a large
stream with requests of randomly assigned priorities. Preemption will be
occasionally requested, but unlikely to ever succeed! (Although we may
build a long queue of requests and so may trigger an attempt to inject a
preempt context, as we emit no batch, the arbitration window is limited
to between requests inside the ringbuffer. The likelihood of actually
causing a preemption event is therefore very small. A later variant
should try to improve the likelihood of preemption events!)

v2: Include a second pattern with more frequent preemption
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180925083205.2229-1-chris@chris-wilson.co.uk
parent e7351a84
...@@ -6,6 +6,7 @@ ...@@ -6,6 +6,7 @@
#include "../i915_selftest.h" #include "../i915_selftest.h"
#include "igt_flush_test.h" #include "igt_flush_test.h"
#include "i915_random.h"
#include "mock_context.h" #include "mock_context.h"
...@@ -573,6 +574,141 @@ static int live_preempt_hang(void *arg) ...@@ -573,6 +574,141 @@ static int live_preempt_hang(void *arg)
return err; return err;
} }
static int random_range(struct rnd_state *rnd, int min, int max)
{
return i915_prandom_u32_max_state(max - min, rnd) + min;
}
static int random_priority(struct rnd_state *rnd)
{
return random_range(rnd, I915_PRIORITY_MIN, I915_PRIORITY_MAX);
}
struct preempt_smoke {
struct drm_i915_private *i915;
struct i915_gem_context **contexts;
unsigned int ncontext;
struct rnd_state prng;
};
static struct i915_gem_context *smoke_context(struct preempt_smoke *smoke)
{
return smoke->contexts[i915_prandom_u32_max_state(smoke->ncontext,
&smoke->prng)];
}
static int smoke_crescendo(struct preempt_smoke *smoke)
{
struct intel_engine_cs *engine;
enum intel_engine_id id;
unsigned long count;
count = 0;
for_each_engine(engine, smoke->i915, id) {
IGT_TIMEOUT(end_time);
do {
struct i915_gem_context *ctx = smoke_context(smoke);
struct i915_request *rq;
ctx->sched.priority = count % I915_PRIORITY_MAX;
rq = i915_request_alloc(engine, ctx);
if (IS_ERR(rq))
return PTR_ERR(rq);
i915_request_add(rq);
count++;
} while (!__igt_timeout(end_time, NULL));
}
pr_info("Submitted %lu crescendo requests across %d engines and %d contexts\n",
count, INTEL_INFO(smoke->i915)->num_rings, smoke->ncontext);
return 0;
}
static int smoke_random(struct preempt_smoke *smoke)
{
struct intel_engine_cs *engine;
enum intel_engine_id id;
IGT_TIMEOUT(end_time);
unsigned long count;
count = 0;
do {
for_each_engine(engine, smoke->i915, id) {
struct i915_gem_context *ctx = smoke_context(smoke);
struct i915_request *rq;
ctx->sched.priority = random_priority(&smoke->prng);
rq = i915_request_alloc(engine, ctx);
if (IS_ERR(rq))
return PTR_ERR(rq);
i915_request_add(rq);
count++;
}
} while (!__igt_timeout(end_time, NULL));
pr_info("Submitted %lu random requests across %d engines and %d contexts\n",
count, INTEL_INFO(smoke->i915)->num_rings, smoke->ncontext);
return 0;
}
static int live_preempt_smoke(void *arg)
{
struct preempt_smoke smoke = {
.i915 = arg,
.prng = I915_RND_STATE_INITIALIZER(i915_selftest.random_seed),
.ncontext = 1024,
};
int err = -ENOMEM;
int n;
if (!HAS_LOGICAL_RING_PREEMPTION(smoke.i915))
return 0;
smoke.contexts = kmalloc_array(smoke.ncontext,
sizeof(*smoke.contexts),
GFP_KERNEL);
if (!smoke.contexts)
return -ENOMEM;
mutex_lock(&smoke.i915->drm.struct_mutex);
intel_runtime_pm_get(smoke.i915);
for (n = 0; n < smoke.ncontext; n++) {
smoke.contexts[n] = kernel_context(smoke.i915);
if (!smoke.contexts[n])
goto err_ctx;
}
err = smoke_crescendo(&smoke);
if (err)
goto err_ctx;
err = smoke_random(&smoke);
if (err)
goto err_ctx;
err_ctx:
if (igt_flush_test(smoke.i915, I915_WAIT_LOCKED))
err = -EIO;
for (n = 0; n < smoke.ncontext; n++) {
if (!smoke.contexts[n])
break;
kernel_context_close(smoke.contexts[n]);
}
intel_runtime_pm_put(smoke.i915);
mutex_unlock(&smoke.i915->drm.struct_mutex);
kfree(smoke.contexts);
return err;
}
int intel_execlists_live_selftests(struct drm_i915_private *i915) int intel_execlists_live_selftests(struct drm_i915_private *i915)
{ {
static const struct i915_subtest tests[] = { static const struct i915_subtest tests[] = {
...@@ -580,6 +716,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) ...@@ -580,6 +716,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
SUBTEST(live_preempt), SUBTEST(live_preempt),
SUBTEST(live_late_preempt), SUBTEST(live_late_preempt),
SUBTEST(live_preempt_hang), SUBTEST(live_preempt_hang),
SUBTEST(live_preempt_smoke),
}; };
if (!HAS_EXECLISTS(i915)) if (!HAS_EXECLISTS(i915))
......
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