[PATCH 31/55] drm/i915: Apply an execution_mask to the virtual_engine
Chris Wilson
chris at chris-wilson.co.uk
Sun Apr 14 18:16:30 UTC 2019
Allow the user to direct which physical engines of the virtual engine
they wish to execute one, as sometimes it is necessary to override the
load balancing algorithm.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/intel_lrc.c | 58 +++++++++++
drivers/gpu/drm/i915/gt/selftest_lrc.c | 131 +++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_request.c | 1 +
drivers/gpu/drm/i915/i915_request.h | 3 +
4 files changed, 193 insertions(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index d6efd6aa67cb..560a18bb4cbb 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -552,6 +552,18 @@ execlists_context_schedule_out(struct i915_request *rq, unsigned long status)
intel_engine_context_out(rq->engine);
execlists_context_status_change(rq, status);
trace_i915_request_out(rq);
+
+ /*
+ * If this is part of a virtual engine, its next request may have
+ * been blocked waiting for access to the active context. We have
+ * to kick all the siblings again in case we need to switch (e.g.
+ * the next request is not runnable on this engine). Hopefully,
+ * we will already have submitted the next request before the
+ * tasklet runs and do not need to rebuild each virtual tree
+ * and kick everyone again.
+ */
+ if (rq->engine != rq->hw_context->engine)
+ tasklet_schedule(&rq->hw_context->engine->execlists.tasklet);
}
static u64 execlists_update_context(struct i915_request *rq)
@@ -779,6 +791,9 @@ static bool virtual_matches(const struct virtual_engine *ve,
{
const struct intel_engine_cs *active;
+ if (!(rq->execution_mask & engine->mask)) /* We peeked too soon! */
+ return false;
+
/*
* We track when the HW has completed saving the context image
* (i.e. when we have seen the final CS event switching out of
@@ -3139,12 +3154,44 @@ static const struct intel_context_ops virtual_context_ops = {
.destroy = virtual_context_destroy,
};
+static intel_engine_mask_t virtual_submission_mask(struct virtual_engine *ve)
+{
+ struct i915_request *rq;
+ intel_engine_mask_t mask;
+
+ rq = READ_ONCE(ve->request);
+ if (!rq)
+ return 0;
+
+ /* The rq is ready for submission; rq->execution_mask is now stable. */
+ mask = rq->execution_mask;
+ if (unlikely(!mask)) {
+ /* Invalid selection, submit to a random engine in error */
+ i915_request_skip(rq, -ENODEV);
+ mask = ve->siblings[0]->mask;
+ }
+
+ GEM_TRACE("%s: rq=%llx:%lld, mask=%x, prio=%d\n",
+ ve->base.name,
+ rq->fence.context, rq->fence.seqno,
+ mask, ve->base.execlists.queue_priority_hint);
+
+ return mask;
+}
+
static void virtual_submission_tasklet(unsigned long data)
{
struct virtual_engine * const ve = (struct virtual_engine *)data;
const int prio = ve->base.execlists.queue_priority_hint;
+ intel_engine_mask_t mask;
unsigned int n;
+ rcu_read_lock();
+ mask = virtual_submission_mask(ve);
+ rcu_read_unlock();
+ if (unlikely(!mask))
+ return;
+
local_irq_disable();
for (n = 0; READ_ONCE(ve->request) && n < ve->num_siblings; n++) {
struct intel_engine_cs *sibling = ve->siblings[n];
@@ -3152,6 +3199,17 @@ static void virtual_submission_tasklet(unsigned long data)
struct rb_node **parent, *rb;
bool first;
+ if (unlikely(!(mask & sibling->mask))) {
+ if (!RB_EMPTY_NODE(&node->rb)) {
+ spin_lock(&sibling->timeline.lock);
+ rb_erase_cached(&node->rb,
+ &sibling->execlists.virtual);
+ RB_CLEAR_NODE(&node->rb);
+ spin_unlock(&sibling->timeline.lock);
+ }
+ continue;
+ }
+
spin_lock(&sibling->timeline.lock);
if (!RB_EMPTY_NODE(&node->rb)) {
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index f34aa9e042a3..209e51ef13e6 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -1480,6 +1480,136 @@ static int live_virtual_engine(void *arg)
return err;
}
+static int mask_virtual_engine(struct drm_i915_private *i915,
+ struct intel_engine_cs **siblings,
+ unsigned int nsibling)
+{
+ struct i915_request *request[MAX_ENGINE_INSTANCE + 1];
+ struct i915_gem_context *ctx;
+ struct intel_context *ve;
+ struct igt_live_test t;
+ unsigned int n;
+ int err;
+
+ /*
+ * Check that by setting the execution mask on a request, we can
+ * restrict it to our desired engine within the virtual engine.
+ */
+
+ ctx = kernel_context(i915);
+ if (!ctx)
+ return -ENOMEM;
+
+ ve = intel_execlists_create_virtual(ctx, siblings, nsibling);
+ if (IS_ERR(ve)) {
+ err = PTR_ERR(ve);
+ goto out_close;
+ }
+
+ err = intel_context_pin(ve);
+ if (err)
+ goto out_put;
+
+ err = igt_live_test_begin(&t, i915, __func__, ve->engine->name);
+ if (err)
+ goto out_unpin;
+
+ for (n = 0; n < nsibling; n++) {
+ request[n] = i915_request_create(ve);
+ if (IS_ERR(request)) {
+ err = PTR_ERR(request);
+ nsibling = n;
+ goto out;
+ }
+
+ /* Reverse order as it's more likely to be unnatural */
+ request[n]->execution_mask = siblings[nsibling - n - 1]->mask;
+
+ i915_request_get(request[n]);
+ i915_request_add(request[n]);
+ }
+
+ for (n = 0; n < nsibling; n++) {
+ if (i915_request_wait(request[n], I915_WAIT_LOCKED, HZ / 10) < 0) {
+ pr_err("%s(%s): wait for %llx:%lld timed out\n",
+ __func__, ve->engine->name,
+ request[n]->fence.context,
+ request[n]->fence.seqno);
+
+ GEM_TRACE("%s(%s) failed at request %llx:%lld\n",
+ __func__, ve->engine->name,
+ request[n]->fence.context,
+ request[n]->fence.seqno);
+ GEM_TRACE_DUMP();
+ i915_gem_set_wedged(i915);
+ err = -EIO;
+ goto out;
+ }
+
+ if (request[n]->engine != siblings[nsibling - n - 1]) {
+ pr_err("Executed on wrong sibling '%s', expected '%s'\n",
+ request[n]->engine->name,
+ siblings[nsibling - n - 1]->name);
+ err = -EINVAL;
+ goto out;
+ }
+ }
+
+ err = igt_live_test_end(&t);
+ if (err)
+ goto out;
+
+out:
+ if (igt_flush_test(i915, I915_WAIT_LOCKED))
+ err = -EIO;
+
+ for (n = 0; n < nsibling; n++)
+ i915_request_put(request[n]);
+
+out_unpin:
+ intel_context_unpin(ve);
+out_put:
+ intel_context_put(ve);
+out_close:
+ kernel_context_close(ctx);
+ return err;
+}
+
+static int live_virtual_mask(void *arg)
+{
+ struct drm_i915_private *i915 = arg;
+ struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
+ unsigned int class, inst;
+ int err = 0;
+
+ if (USES_GUC_SUBMISSION(i915))
+ return 0;
+
+ mutex_lock(&i915->drm.struct_mutex);
+
+ for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
+ unsigned int nsibling;
+
+ nsibling = 0;
+ for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
+ if (!i915->engine_class[class][inst])
+ break;
+
+ siblings[nsibling++] = i915->engine_class[class][inst];
+ }
+ if (nsibling < 2)
+ continue;
+
+ err = mask_virtual_engine(i915, siblings, nsibling);
+ if (err)
+ goto out_unlock;
+ }
+
+out_unlock:
+ mutex_unlock(&i915->drm.struct_mutex);
+ return err;
+}
+
int intel_execlists_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
@@ -1493,6 +1623,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
SUBTEST(live_preempt_hang),
SUBTEST(live_preempt_smoke),
SUBTEST(live_virtual_engine),
+ SUBTEST(live_virtual_mask),
};
if (!HAS_EXECLISTS(i915))
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 891e31d54307..9352406d5504 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -687,6 +687,7 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
rq->batch = NULL;
rq->capture_list = NULL;
rq->waitboost = false;
+ rq->execution_mask = ALL_ENGINES;
INIT_LIST_HEAD(&rq->active_list);
INIT_LIST_HEAD(&rq->execute_cb);
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 8025a89b5999..d7f9b2194568 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -28,6 +28,8 @@
#include <linux/dma-fence.h>
#include <linux/lockdep.h>
+#include "gt/intel_engine_types.h"
+
#include "i915_gem.h"
#include "i915_scheduler.h"
#include "i915_selftest.h"
@@ -156,6 +158,7 @@ struct i915_request {
*/
struct i915_sched_node sched;
struct i915_dependency dep;
+ intel_engine_mask_t execution_mask;
/*
* A convenience pointer to the current breadcrumb value stored in
--
2.20.1
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