diff options
| -rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_gt_pm.c | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_rps.c | 138 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_rps.h | 1 |
3 files changed, 140 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/selftest_gt_pm.c b/drivers/gpu/drm/i915/gt/selftest_gt_pm.c index c50bb502fe03..0141c334f2ac 100644 --- a/drivers/gpu/drm/i915/gt/selftest_gt_pm.c +++ b/drivers/gpu/drm/i915/gt/selftest_gt_pm.c @@ -54,6 +54,7 @@ int intel_gt_pm_live_selftests(struct drm_i915_private *i915) static const struct i915_subtest tests[] = { SUBTEST(live_rc6_manual), SUBTEST(live_rps_interrupt), + SUBTEST(live_rps_power), SUBTEST(live_gt_resume), }; diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c index e60600d14937..360f56aa4b82 100644 --- a/drivers/gpu/drm/i915/gt/selftest_rps.c +++ b/drivers/gpu/drm/i915/gt/selftest_rps.c @@ -3,12 +3,15 @@ * Copyright © 2020 Intel Corporation */ +#include <linux/sort.h> + #include "intel_engine_pm.h" #include "intel_gt_pm.h" #include "intel_rc6.h" #include "selftest_rps.h" #include "selftests/igt_flush_test.h" #include "selftests/igt_spinner.h" +#include "selftests/librapl.h" static void dummy_rps_work(struct work_struct *wrk) { @@ -231,3 +234,138 @@ out: return err; } + +static u64 __measure_power(int duration_ms) +{ + u64 dE, dt; + + dt = ktime_get(); + dE = librapl_energy_uJ(); + usleep_range(1000 * duration_ms, 2000 * duration_ms); + dE = librapl_energy_uJ() - dE; + dt = ktime_get() - dt; + + return div64_u64(1000 * 1000 * dE, dt); +} + +static int cmp_u64(const void *A, const void *B) +{ + const u64 *a = A, *b = B; + + if (a < b) + return -1; + else if (a > b) + return 1; + else + return 0; +} + +static u64 measure_power_at(struct intel_rps *rps, int freq) +{ + u64 x[5]; + int i; + + mutex_lock(&rps->lock); + GEM_BUG_ON(!rps->active); + intel_rps_set(rps, freq); + mutex_unlock(&rps->lock); + + msleep(20); /* more than enough time to stabilise! */ + + i = read_cagf(rps); + if (i != freq) + pr_notice("Running at %x [%uMHz], not target %x [%uMHz]\n", + i, intel_gpu_freq(rps, i), + freq, intel_gpu_freq(rps, freq)); + + for (i = 0; i < 5; i++) + x[i] = __measure_power(5); + + /* A simple triangle filter for better result stability */ + sort(x, 5, sizeof(*x), cmp_u64, NULL); + return div_u64(x[1] + 2 * x[2] + x[3], 4); +} + +int live_rps_power(void *arg) +{ + struct intel_gt *gt = arg; + struct intel_rps *rps = >->rps; + void (*saved_work)(struct work_struct *wrk); + struct intel_engine_cs *engine; + enum intel_engine_id id; + struct igt_spinner spin; + int err = 0; + + /* + * Our fundamental assumption is that running at lower frequency + * actually saves power. Let's see if our RAPL measurement support + * that theory. + */ + + if (!rps->enabled || rps->max_freq <= rps->min_freq) + return 0; + + if (!librapl_energy_uJ()) + return 0; + + if (igt_spinner_init(&spin, gt)) + return -ENOMEM; + + intel_gt_pm_wait_for_idle(gt); + saved_work = rps->work.func; + rps->work.func = dummy_rps_work; + + for_each_engine(engine, gt, id) { + struct i915_request *rq; + u64 min, max; + + if (!intel_engine_can_store_dword(engine)) + continue; + + rq = igt_spinner_create_request(&spin, + engine->kernel_context, + MI_NOOP); + if (IS_ERR(rq)) { + err = PTR_ERR(rq); + break; + } + + i915_request_add(rq); + + if (!igt_wait_for_spinner(&spin, rq)) { + pr_err("%s: RPS spinner did not start\n", + engine->name); + intel_gt_set_wedged(engine->gt); + err = -EIO; + break; + } + + max = measure_power_at(rps, rps->max_freq); + min = measure_power_at(rps, rps->min_freq); + + igt_spinner_end(&spin); + + pr_info("%s: min:%llumW @ %uMHz, max:%llumW @ %uMHz\n", + engine->name, + min, intel_gpu_freq(rps, rps->min_freq), + max, intel_gpu_freq(rps, rps->max_freq)); + if (11 * min > 10 * max) { + pr_err("%s: did not conserve power when setting lower frequency!\n", + engine->name); + err = -EINVAL; + break; + } + + if (igt_flush_test(gt->i915)) { + err = -EIO; + break; + } + } + + igt_spinner_fini(&spin); + + intel_gt_pm_wait_for_idle(gt); + rps->work.func = saved_work; + + return err; +} diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.h b/drivers/gpu/drm/i915/gt/selftest_rps.h index abba66420996..cad515a7f0e5 100644 --- a/drivers/gpu/drm/i915/gt/selftest_rps.h +++ b/drivers/gpu/drm/i915/gt/selftest_rps.h @@ -7,5 +7,6 @@ #define SELFTEST_RPS_H int live_rps_interrupt(void *arg); +int live_rps_power(void *arg); #endif /* SELFTEST_RPS_H */ |