On 9/27/2022 4:42 PM, Gupta, Anshuman wrote:
The current librapl_supported has only rapl related changes. The hwmon energy is yet to be added.-----Original Message----- From: Belgaumkar, Vinay <[email protected]> Sent: Monday, September 26, 2022 9:35 PM To: Tauro, Riana <[email protected]>; [email protected] Cc: Gupta, Anshuman <[email protected]>; Dixit, Ashutosh <[email protected]> Subject: Re: [PATCH 3/3] drm/i915/guc/slpc: Add SLPC selftest live_slpc_power On 9/23/2022 4:00 AM, Riana Tauro wrote:A fundamental assumption is that at lower frequencies, not only do we run slower, but we save power compared to higher frequencies. live_slpc_power checks if running at low frequency saves power v2: re-use code to measure power fixed cosmetic review comments (Vinay) Signed-off-by: Riana Tauro <[email protected]>LGTM, Reviewed-by: Vinay Belgaumkar <[email protected]>--- drivers/gpu/drm/i915/gt/selftest_slpc.c | 127 ++++++++++++++++++++++-- 1 file changed, 118 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/selftest_slpc.c b/drivers/gpu/drm/i915/gt/selftest_slpc.c index 928f74718881..4c6e9257e593 100644 --- a/drivers/gpu/drm/i915/gt/selftest_slpc.c +++ b/drivers/gpu/drm/i915/gt/selftest_slpc.c @@ -11,7 +11,8 @@ enum test_type { VARY_MIN, VARY_MAX, - MAX_GRANTED + MAX_GRANTED, + SLPC_POWER, }; static int slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 freq) @@ -41,6 +42,39 @@ static int slpc_set_max_freq(struct intel_guc_slpc *slpc,u32 freq)return ret; } +static int slpc_set_freq(struct intel_gt *gt, u32 freq) { + int err; + struct intel_guc_slpc *slpc = >->uc.guc.slpc; + + err = slpc_set_max_freq(slpc, freq); + if (err) { + pr_err("Unable to update max freq"); + return err; + } + + err = slpc_set_min_freq(slpc, freq); + if (err) { + pr_err("Unable to update min freq"); + return err; + } + + return err; +} + +static u64 measure_power_at_freq(struct intel_gt *gt, int *freq, u64 +*power) { + int err = 0; + + err = slpc_set_freq(gt, *freq); + if (err) + return err; + *freq = intel_rps_read_actual_frequency(>->rps); + *power = measure_power(>->rps, freq); + + return err; +} + static int vary_max_freq(struct intel_guc_slpc *slpc, struct intel_rps *rps, u32 *max_act_freq) { @@ -113,6 +147,58 @@ static int vary_min_freq(struct intel_guc_slpc *slpc,struct intel_rps *rps,return err; } +static int slpc_power(struct intel_gt *gt, struct intel_engine_cs +*engine) { + struct intel_guc_slpc *slpc = >->uc.guc.slpc; + struct { + u64 power; + int freq; + } min, max; + int err = 0; + + /* + * Our fundamental assumption is that running at lower frequency + * actually saves power. Let's see if our RAPL measurement supports + * that theory. + */ + if (!librapl_supported(gt->i915)) + return 0;This seems a wrong abstraction, this should a generic call should check both hwmon registration for dgfx and rapl for igfx. Br, Anshuman Gupta.
Will change the name with the hwmon patch Thanks Riana Tauro
+ + min.freq = slpc->min_freq; + err = measure_power_at_freq(gt, &min.freq, &min.power); + + if (err) + return err; + + max.freq = slpc->rp0_freq; + err = measure_power_at_freq(gt, &max.freq, &max.power); + + if (err) + return err; + + pr_info("%s: min:%llumW @ %uMHz, max:%llumW @ %uMHz\n", + engine->name, + min.power, min.freq, + max.power, max.freq); + + if (10 * min.freq >= 9 * max.freq) { + pr_notice("Could not control frequency, ran at [%uMHz,%uMhz]\n",+ min.freq, max.freq); + } + + if (11 * min.power > 10 * max.power) { + pr_err("%s: did not conserve power when setting lowerfrequency!\n",+ engine->name); + err = -EINVAL; + } + + /* Restore min/max frequencies */ + slpc_set_max_freq(slpc, slpc->rp0_freq); + slpc_set_min_freq(slpc, slpc->min_freq); + + return err; +} + static int max_granted_freq(struct intel_guc_slpc *slpc, struct intel_rps *rps,u32 *max_act_freq){ struct intel_gt *gt = rps_to_gt(rps); @@ -233,17 +319,23 @@ static int run_test(struct intel_gt *gt, int test_type) err = max_granted_freq(slpc, rps, &max_act_freq); break; + + case SLPC_POWER: + err = slpc_power(gt, engine); + break; } - pr_info("Max actual frequency for %s was %d\n", - engine->name, max_act_freq); + if (test_type != SLPC_POWER) { + pr_info("Max actual frequency for %s was %d\n", + engine->name, max_act_freq); - /* Actual frequency should rise above min */ - if (max_act_freq <= slpc_min_freq) { - pr_err("Actual freq did not rise above min\n"); - pr_err("Perf Limit Reasons: 0x%x\n", - intel_uncore_read(gt->uncore,GT0_PERF_LIMIT_REASONS));- err = -EINVAL; + /* Actual frequency should rise above min */ + if (max_act_freq <= slpc_min_freq) { + pr_err("Actual freq did not rise above min\n"); + pr_err("Perf Limit Reasons: 0x%x\n", + intel_uncore_read(gt->uncore,GT0_PERF_LIMIT_REASONS));+ err = -EINVAL; + } } igt_spinner_end(&spin); @@ -316,12 +408,29 @@ static int live_slpc_max_granted(void *arg) return ret; } +static int live_slpc_power(void *arg) { + struct drm_i915_private *i915 = arg; + struct intel_gt *gt; + unsigned int i; + int ret; + + for_each_gt(gt, i915, i) { + ret = run_test(gt, SLPC_POWER); + if (ret) + return ret; + } + + return ret; +} + int intel_slpc_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { SUBTEST(live_slpc_vary_max), SUBTEST(live_slpc_vary_min), SUBTEST(live_slpc_max_granted), + SUBTEST(live_slpc_power), }; struct intel_gt *gt;
