On Mon, Dec 13, 2021 at 04:26:07PM -0800, John Harrison wrote:
> On 12/11/2021 09:35, Matthew Brost wrote:
> > Testing the stealing of guc ids is hard from user space as we have 64k
> > guc_ids. Add a selftest, which artificially reduces the number of guc
> > ids, and forces a steal. Description of test below.
> Last sentence seems redundant.
>
Will delete.
> >
> > The test creates a spinner which is used to block all subsequent
> > submissions until it completes. Next, a loop creates a context and a NOP
> > request each iteration until the guc_ids are exhausted (request creation
> > returns -EAGAIN). The spinner is ended, unblocking all requests created
> > in the loop. At this point all guc_ids are exhausted but are available
> > to steal. Try to create another request which should successfully steal
> > a guc_id. Wait on last request to complete, idle GPU, verify a guc_id
> > was stolen via a counter, and exit the test. Test also artificially
> > reduces the number of guc_ids so the test runs in a timely manner.
> >
> > v2:
> > (John Harrison)
> > - s/stole/stolen
> > - Fix some wording in test description
> > - Rework indexing into context array
> > - Add test description to commit message
> > - Fix typo in commit message
> > (Checkpatch)
> > - s/guc/(guc) in NUMBER_MULTI_LRC_GUC_ID
> >
> > Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/gt/uc/intel_guc.h | 12 ++
> > .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 16 +-
> > drivers/gpu/drm/i915/gt/uc/selftest_guc.c | 173 ++++++++++++++++++
> > 3 files changed, 196 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
> > index 1cb46098030d..f9240d4baa69 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
> > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
> > @@ -94,6 +94,11 @@ struct intel_guc {
> > * @guc_ids: used to allocate new guc_ids, single-lrc
> > */
> > struct ida guc_ids;
> > + /**
> > + * @num_guc_ids: Number of guc_ids, selftest feature to be able
> > + * to reduce this number while testing.
> > + */
> > + int num_guc_ids;
> > /**
> > * @guc_ids_bitmap: used to allocate new guc_ids, multi-lrc
> > */
> > @@ -202,6 +207,13 @@ struct intel_guc {
> > */
> > struct delayed_work work;
> > } timestamp;
> > +
> > +#ifdef CONFIG_DRM_I915_SELFTEST
> > + /**
> > + * @number_guc_id_stolen: The number of guc_ids that have been stolen
> > + */
> > + int number_guc_id_stolen;
> > +#endif
> > };
> > static inline struct intel_guc *log_to_guc(struct intel_guc_log *log)
> > 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 96fcf869e3ff..99414b49ca6d 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > @@ -145,7 +145,8 @@ guc_create_parallel(struct intel_engine_cs **engines,
> > * use should be low and 1/16 should be sufficient. Minimum of 32 guc_ids for
> > * multi-lrc.
> > */
> > -#define NUMBER_MULTI_LRC_GUC_ID (GUC_MAX_LRC_DESCRIPTORS / 16)
> > +#define NUMBER_MULTI_LRC_GUC_ID(guc) \
> > + ((guc)->submission_state.num_guc_ids / 16)
> > /*
> > * Below is a set of functions which control the GuC scheduling state which
> > @@ -1775,7 +1776,7 @@ int intel_guc_submission_init(struct intel_guc *guc)
> > destroyed_worker_func);
> > guc->submission_state.guc_ids_bitmap =
> > - bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID, GFP_KERNEL);
> > + bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID(guc), GFP_KERNEL);
> > if (!guc->submission_state.guc_ids_bitmap)
> > return -ENOMEM;
> > @@ -1869,13 +1870,13 @@ static int new_guc_id(struct intel_guc *guc, struct intel_context *ce)
> > if (intel_context_is_parent(ce))
> > ret = bitmap_find_free_region(guc->submission_state.guc_ids_bitmap,
> > - NUMBER_MULTI_LRC_GUC_ID,
> > + NUMBER_MULTI_LRC_GUC_ID(guc),
> > order_base_2(ce->parallel.number_children
> > + 1));
> > else
> > ret = ida_simple_get(&guc->submission_state.guc_ids,
> > - NUMBER_MULTI_LRC_GUC_ID,
> > - GUC_MAX_LRC_DESCRIPTORS,
> > + NUMBER_MULTI_LRC_GUC_ID(guc),
> > + guc->submission_state.num_guc_ids,
> > GFP_KERNEL | __GFP_RETRY_MAYFAIL |
> > __GFP_NOWARN);
> > if (unlikely(ret < 0))
> > @@ -1941,6 +1942,10 @@ static int steal_guc_id(struct intel_guc *guc, struct intel_context *ce)
> > set_context_guc_id_invalid(cn);
> > +#ifdef CONFIG_DRM_I915_SELFTEST
> > + guc->number_guc_id_stolen++;
> > +#endif
> > +
> > return 0;
> > } else {
> > return -EAGAIN;
> > @@ -3779,6 +3784,7 @@ static bool __guc_submission_selected(struct intel_guc *guc)
> > void intel_guc_submission_init_early(struct intel_guc *guc)
> > {
> > + guc->submission_state.num_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
> > guc->submission_supported = __guc_submission_supported(guc);
> > guc->submission_selected = __guc_submission_selected(guc);
> > }
> > diff --git a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
> > index fb0e4a7bd8ca..90f5eb66281c 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
> > +++ b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
> > @@ -3,8 +3,21 @@
> > * Copyright �� 2021 Intel Corporation
> > */
> > +#include "selftests/igt_spinner.h"
> > #include "selftests/intel_scheduler_helpers.h"
> > +static int request_add_spin(struct i915_request *rq, struct igt_spinner *spin)
> > +{
> > + int err = 0;
> > +
> > + i915_request_get(rq);
> > + i915_request_add(rq);
> > + if (spin && !igt_wait_for_spinner(spin, rq))
> > + err = -ETIMEDOUT;
> > +
> > + return err;
> > +}
> > +
> > static struct i915_request *nop_user_request(struct intel_context *ce,
> > struct i915_request *from)
> > {
> > @@ -110,10 +123,170 @@ static int intel_guc_scrub_ctbs(void *arg)
> > return ret;
> > }
> > +/*
> > + * intel_guc_steal_guc_ids - Test to exhaust all guc_ids and then steal one
> > + *
> > + * This test creates a spinner which is used to block all subsequent submissions
> > + * until it completes. Next, a loop creates a context and a NOP request each
> > + * iteration until the guc_ids are exhausted (request creation returns -EAGAIN).
> > + * The spinner is ended, unblocking all requests created in the loop. At this
> > + * point all guc_ids are exhausted but are available to steal. Try to create
> > + * another request which should successfully steal a guc_id. Wait on last
> > + * request to complete, idle GPU, verify a guc_id was stolen via a counter, and
> > + * exit the test. Test also artificially reduces the number of guc_ids so the
> > + * test runs in a timely manner.
> > + */
> > +static int intel_guc_steal_guc_ids(void *arg)
> > +{
> > + struct intel_gt *gt = arg;
> > + struct intel_guc *guc = >->uc.guc;
> > + int ret, sv, context_index = 0;
> > + intel_wakeref_t wakeref;
> > + struct intel_engine_cs *engine;
> > + struct intel_context **ce;
> > + struct igt_spinner spin;
> > + struct i915_request *spin_rq = NULL, *rq, *last = NULL;
> > + int number_guc_id_stolen = guc->number_guc_id_stolen;
> > +
> > + ce = kzalloc(sizeof(*ce) * GUC_MAX_LRC_DESCRIPTORS, GFP_KERNEL);
> > + if (!ce) {
> > + pr_err("Context array allocation failed\n");
> > + return -ENOMEM;
> > + }
> > +
> > + wakeref = intel_runtime_pm_get(gt->uncore->rpm);
> > + engine = intel_selftest_find_any_engine(gt);
> > + sv = guc->submission_state.num_guc_ids;
> > + guc->submission_state.num_guc_ids = 4096;
> > +
> > + /* Create spinner to block requests in below loop */
> > + ce[context_index] = intel_context_create(engine);
> > + if (IS_ERR(ce[context_index])) {
> > + ce[context_index] = NULL;
> > + ret = PTR_ERR(ce[context_index]);
> Um, this is now null!
>
Ugh, wrong order. Will fix.
> > + pr_err("Failed to create context: %d\n", ret);
> > + goto err_wakeref;
> > + }
> > + ret = igt_spinner_init(&spin, engine->gt);
> > + if (ret) {
> > + pr_err("Failed to create spinner: %d\n", ret);
> > + goto err_contexts;
> > + }
> > + spin_rq = igt_spinner_create_request(&spin, ce[context_index],
> > + MI_ARB_CHECK);
> > + if (IS_ERR(spin_rq)) {
> > + ret = PTR_ERR(spin_rq);
> > + pr_err("Failed to create spinner request: %d\n", ret);
> > + goto err_contexts;
> > + }
> > + ret = request_add_spin(spin_rq, &spin);
> > + if (ret) {
> > + pr_err("Failed to add Spinner request: %d\n", ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + /* Use all guc_ids */
> > + while (ret != -EAGAIN) {
> > + ce[++context_index] = intel_context_create(engine);
> > + if (IS_ERR(ce[context_index])) {
> > + ce[context_index] = NULL;
> > + ret = PTR_ERR(ce[context_index--]);
> And again.
>
Same.
> > + pr_err("Failed to create context: %d\n", ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + rq = nop_user_request(ce[context_index], spin_rq);
> > + if (IS_ERR(rq)) {
> > + ret = PTR_ERR(rq);
> > + rq = NULL;
> > + if (ret != -EAGAIN) {
> > + pr_err("Failed to create request, %d: %d\n",
> > + context_index, ret);
> > + goto err_spin_rq;
> > + }
> > + } else {
> > + if (last)
> > + i915_request_put(last);
> > + last = rq;
> > + }
> > + }
> > +
> > + /* Release blocked requests */
> > + igt_spinner_end(&spin);
> > + ret = intel_selftest_wait_for_rq(spin_rq);
> > + if (ret) {
> > + pr_err("Spin request failed to complete: %d\n", ret);
> > + i915_request_put(last);
> > + goto err_spin_rq;
> > + }
> > + i915_request_put(spin_rq);
> > + igt_spinner_fini(&spin);
> > + spin_rq = NULL;
> > +
> > + /* Wait for last request */
> > + ret = i915_request_wait(last, 0, HZ * 30);
> > + i915_request_put(last);
> > + if (ret < 0) {
> > + pr_err("Last request failed to complete: %d\n", ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + /* Try to steal guc_id */
> > + rq = nop_user_request(ce[context_index], NULL);
> > + if (IS_ERR(rq)) {
> > + ret = PTR_ERR(rq);
> > + pr_err("Failed to steal guc_id, %d: %d\n", context_index, ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + /* Wait for request with stolen guc_id */
> > + ret = i915_request_wait(rq, 0, HZ);
> > + i915_request_put(rq);
> > + if (ret < 0) {
> > + pr_err("Request with stolen guc_id failed to complete: %d\n",
> > + ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + /* Wait for idle */
> > + ret = intel_gt_wait_for_idle(gt, HZ * 30);
> > + if (ret < 0) {
> > + pr_err("GT failed to idle: %d\n", ret);
> > + goto err_spin_rq;
> > + }
> > +
> > + /* Verify a guc_id got stolen */
> got stolen -> was stolen
>
Yes.
> > + if (guc->number_guc_id_stolen == number_guc_id_stolen) {
> > + pr_err("No guc_ids stolenn");
> ids stolenn -> id was stolen
>
And yes.
> John.
>
> > + ret = -EINVAL;
> > + } else {
> > + ret = 0;
> > + }
> > +
> > +err_spin_rq:
> > + if (spin_rq) {
> > + igt_spinner_end(&spin);
> > + intel_selftest_wait_for_rq(spin_rq);
> > + i915_request_put(spin_rq);
> > + igt_spinner_fini(&spin);
> > + intel_gt_wait_for_idle(gt, HZ * 30);
> > + }
> > +err_contexts:
> > + for (; context_index >= 0 && ce[context_index]; --context_index)
> > + intel_context_put(ce[context_index]);
> > +err_wakeref:
> > + intel_runtime_pm_put(gt->uncore->rpm, wakeref);
> > + kfree(ce);
> > + guc->submission_state.num_guc_ids = sv;
> > +
> > + return ret;
> > +}
> > +
> > int intel_guc_live_selftests(struct drm_i915_private *i915)
> > {
> > static const struct i915_subtest tests[] = {
> > SUBTEST(intel_guc_scrub_ctbs),
> > + SUBTEST(intel_guc_steal_guc_ids),
> > };
> > struct intel_gt *gt = &i915->gt;
>
