[Intel-gfx] [PATCH 7/7] drm/i915/guc: Selftest for stealing of guc ids
John Harrison
john.c.harrison at intel.com
Tue Dec 14 19:48:54 UTC 2021
On 12/14/2021 09:05, 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.
>
> 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
> v3:
> (John Harrison)
> - Set array value to NULL after extracting error
> - Fix a few typos in comments / error messages
> - Delete redundant comment in commit message
>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Reviewed-by: John Harrison <John.C.Harrison at Intel.com>
> ---
> 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..2ae414446112 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])) {
> + ret = PTR_ERR(ce[context_index]);
> + ce[context_index] = NULL;
> + 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])) {
> + ret = PTR_ERR(ce[context_index--]);
> + ce[context_index] = NULL;
> + 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 was stolen */
> + if (guc->number_guc_id_stolen == number_guc_id_stolen) {
> + pr_err("No guc_id was stolen");
> + 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;
>
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