[PATCH v7 1/2] tests/i915/pm_rc6_residency: Use sysfs to achieve peak frequency
Anirban, Sk
sk.anirban at intel.com
Mon Jun 2 10:16:54 UTC 2025
Hi Kamil,
On 31-05-2025 01:13, Kamil Konieczny wrote:
> Hi Sk,
> On 2025-05-29 at 14:38:40 +0530, Sk Anirban wrote:
>> Leverage IGT spinner to trigger frequency scaling and
>> set RPS minimum frequency to RP0 for achieving peak frequency.
>> This method replaces the existing waitboost mechanism used
>> to reach maximum frequency.
>>
>> v4:
>> - Cosmetic changes (Riana)
>>
>> v5:
>> - Limit the power consumption test to GT0 only
> Imho this should be a separate patch with its own description
> why you need only for GT0.
The test was targeting GT0 only in the past. Maybe I will add a
descriptive commit message for this.
>> v6:
>> - Fix frequency restoration (Riana)
>>
>> v7:
>> - Fix variable scope (Riana)
>>
>> Signed-off-by: Sk Anirban <sk.anirban at intel.com>
>> Reviewed-by: Riana Tauro <riana.tauro at intel.com>
>> ---
>> tests/intel/i915_pm_rc6_residency.c | 125 +++++++++++++++++++---------
>> 1 file changed, 86 insertions(+), 39 deletions(-)
>>
>> diff --git a/tests/intel/i915_pm_rc6_residency.c b/tests/intel/i915_pm_rc6_residency.c
>> index c9128481d..e7a34b0da 100644
>> --- a/tests/intel/i915_pm_rc6_residency.c
>> +++ b/tests/intel/i915_pm_rc6_residency.c
>> @@ -264,17 +264,6 @@ static bool __pmu_wait_for_rc6(int fd)
>> return false;
>> }
>>
>> -static uint32_t batch_create(int fd)
>> -{
>> - const uint32_t bbe = MI_BATCH_BUFFER_END;
>> - uint32_t handle;
>> -
>> - handle = gem_create(fd, 4096);
>> - gem_write(fd, handle, 0, &bbe, sizeof(bbe));
>> -
>> - return handle;
>> -}
>> -
>> static int open_pmu(int i915, uint64_t config)
>> {
>> int fd;
>> @@ -286,45 +275,88 @@ static int open_pmu(int i915, uint64_t config)
>> return fd;
>> }
>>
>> -#define WAITBOOST 0x1
>> +#define FREQUENT_BOOST 0x1
>> #define ONCE 0x2
>>
>> static void sighandler(int sig)
>> {
>> }
>>
>> -static void bg_load(int i915, uint32_t ctx_id, uint64_t engine_flags, unsigned int flags, unsigned long *ctl)
>> +static uint32_t get_freq(int dirfd, uint8_t id)
>> +{
>> + uint32_t val;
>> +
>> + igt_assert(igt_sysfs_rps_scanf(dirfd, id, "%u", &val) == 1);
>> +
>> + return val;
>> +}
>> +
>> +static int set_freq(int dirfd, uint8_t id, uint32_t val)
>> +{
>> + return igt_sysfs_rps_printf(dirfd, id, "%u", val);
>> +}
>> +
>> +uint32_t stash_min;
> ^
> static uint32_t stash_min;
>
> Also add:
> static int s_dirfd = -1;
>
>> +
>> +static void restore_freq(int sig)
>> +{
>> + int i915 = -1;
>> + int dirfd;
>> + int gt = 0;
>> +
> Add here:
> if (s_dirfd == -1)
> return;
>
>> + i915 = drm_open_driver(DRIVER_INTEL);
>> + dirfd = igt_sysfs_gt_open(i915, 0);
>> + igt_sysfs_gt_open(i915, gt);
>> +
>> + igt_assert_lt(0, set_freq(dirfd, RPS_MIN_FREQ_MHZ, stash_min));
>> +
>> + drm_close_driver(i915);
> This looks incorrect, in signal handler you should only make one
> write with restoration of stash_min, so only dirfd and stash_min
> are needed.
> Also this is a last call before exit so no asserts here, if you
> really need it you could make restoring with assert at test end.
> In summary, here:
> if (stash_min)
> set_freq(s_dirfd, RPS_MIN_FREQ_MHZ, stash_min);
I will fix the above code, I will be removing the igt_assert from the
restoration block.
>> + close(dirfd);
>> +}
>> +
>> +static void bg_load(int i915, const intel_ctx_t *ctx, int dirfd, uint64_t engine_flags,
>> + unsigned int flags, unsigned long *ctl, unsigned int gt)
>> {
>> const bool has_execlists = intel_gen(intel_get_drm_devid(i915)) >= 8;
>> - struct drm_i915_gem_exec_object2 obj = {
>> - .handle = batch_create(i915),
>> - };
>> - struct drm_i915_gem_execbuffer2 execbuf = {
>> - .buffers_ptr = to_user_pointer(&obj),
>> - .buffer_count = 1,
>> - .flags = engine_flags,
>> - .rsvd1 = ctx_id,
>> - };
>> struct sigaction act = {
>> .sa_handler = sighandler
>> };
>> + int64_t timeout = 1;
>> + uint64_t ahnd;
>> + int rp0;
>>
>> + ahnd = get_reloc_ahnd(i915, ctx->id);
>> + rp0 = get_freq(dirfd, RPS_RP0_FREQ_MHZ);
>> sigaction(SIGINT, &act, NULL);
>> do {
>> uint64_t submit, wait, elapsed;
>> struct timespec tv = {};
>> + igt_spin_t *spin;
>>
>> igt_nsec_elapsed(&tv);
>> -
>> - gem_execbuf(i915, &execbuf);
>> + spin = igt_spin_new(i915,
>> + .ahnd = ahnd,
>> + .ctx = ctx,
>> + .engine = engine_flags);
>> submit = igt_nsec_elapsed(&tv);
>> - if (flags & WAITBOOST) {
>> - gem_sync(i915, obj.handle);
>> + if (flags & FREQUENT_BOOST) {
>> + /* Set MIN freq to RP0 to achieve the peak freq */
>> + igt_assert_lt(0, set_freq(dirfd, RPS_MIN_FREQ_MHZ, rp0));
>> + igt_assert(gem_bo_busy(i915, spin->handle));
>> + gem_wait(i915, spin->handle, &timeout);
>> +
>> + /* Restore the MIN freq back to default */
>> + igt_assert_lt(0, set_freq(dirfd, RPS_MIN_FREQ_MHZ, stash_min));
>> + igt_spin_end(spin);
>> + igt_spin_free(i915, spin);
>> + gem_quiescent_gpu(i915);
>> if (flags & ONCE)
>> - flags &= ~WAITBOOST;
>> + flags &= ~FREQUENT_BOOST;
>> } else {
>> - while (gem_bo_busy(i915, obj.handle))
>> - usleep(0);
>> + igt_assert(gem_bo_busy(i915, spin->handle));
>> + igt_spin_end(spin);
>> + igt_spin_free(i915, spin);
>> + gem_quiescent_gpu(i915);
>> }
>> wait = igt_nsec_elapsed(&tv);
>>
>> @@ -350,6 +382,7 @@ static void bg_load(int i915, uint32_t ctx_id, uint64_t engine_flags, unsigned i
>> /* aim for ~1% busy */
>> usleep(min_t(elapsed, elapsed / 10, 50 * 1000));
>> } while (!READ_ONCE(*ctl));
>> + put_ahnd(ahnd);
>> }
>>
>> static void kill_children(int sig)
>> @@ -361,9 +394,9 @@ static void kill_children(int sig)
>> signal(sig, old);
>> }
>>
>> -static void rc6_idle(int i915, uint32_t ctx_id, uint64_t flags, unsigned int gt)
>> +static void rc6_idle(int i915, const intel_ctx_t *ctx, uint64_t flags, unsigned int gt)
>> {
>> - const int64_t duration_ns = SLEEP_DURATION * (int64_t)NSEC_PER_SEC;
>> + const int64_t duration_ns = 2 * SLEEP_DURATION * (int64_t)NSEC_PER_SEC;
>> const int tolerance = 20; /* Some RC6 is better than none! */
>> const unsigned int gen = intel_gen(intel_get_drm_devid(i915));
>> struct {
>> @@ -371,10 +404,11 @@ static void rc6_idle(int i915, uint32_t ctx_id, uint64_t flags, unsigned int gt)
>> unsigned int flags;
>> double power;
>> } phases[] = {
>> + { "once", FREQUENT_BOOST | ONCE },
>> { "normal", 0 },
>> - { "boost", WAITBOOST },
>> - { "once", WAITBOOST | ONCE },
>> + { "boost", FREQUENT_BOOST }
>> };
>> + int dirfd = igt_sysfs_gt_open(i915, gt);
>> struct power_sample sample[2];
>> unsigned long slept, cycles;
>> unsigned long *done;
>> @@ -407,12 +441,21 @@ static void rc6_idle(int i915, uint32_t ctx_id, uint64_t flags, unsigned int gt)
>>
>> assert_within_epsilon_debug(rc6, ts[1] - ts[0], 5, drpc);
>>
>> + if (gt) {
>> + close(fd);
>> + close(dirfd);
>> + igt_power_close(&gpu);
>> + return;
>> + }
>> +
>> done = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
>>
>> + stash_min = get_freq(dirfd, RPS_MIN_FREQ_MHZ);
>> +
>> for (int p = 0; p < ARRAY_SIZE(phases); p++) {
>> memset(done, 0, 2 * sizeof(*done));
>> igt_fork(child, 1) /* Setup up a very light load */
>> - bg_load(i915, ctx_id, flags, phases[p].flags, done);
>> + bg_load(i915, ctx, dirfd, flags, phases[p].flags, done, gt);
>>
>> igt_power_get_energy(&gpu, &sample[0]);
>> cycles = -READ_ONCE(done[1]);
>> @@ -451,15 +494,16 @@ static void rc6_idle(int i915, uint32_t ctx_id, uint64_t flags, unsigned int gt)
>>
>> munmap(done, 4096);
>> close(fd);
>> + close(dirfd);
>>
>> igt_power_close(&gpu);
>>
>> - if (phases[1].power - phases[0].power > 10) {
>> - igt_assert_f(2 * phases[2].power - phases[0].power <= phases[1].power,
>> + if (phases[2].power - phases[1].power > 20 && !gem_has_lmem(i915)) {
>> + igt_assert_f(2 * phases[0].power - phases[1].power <= phases[2].power,
>> "Exceeded energy expectations for single busy wait load\n"
>> "Used %.1fmW, min %.1fmW, max %.1fmW, expected less than %.1fmW\n",
>> - phases[2].power, phases[0].power, phases[1].power,
>> - phases[0].power + (phases[1].power - phases[0].power) / 2);
>> + phases[0].power, phases[1].power, phases[2].power,
>> + phases[1].power + (phases[2].power - phases[1].power) / 2);
>> }
>> }
>>
>> @@ -582,19 +626,22 @@ igt_main
>> igt_subtest_with_dynamic("rc6-idle") {
>> const struct intel_execution_engine2 *e;
>>
> You should set stash_min and s_dirfd before installing exit handler.
>
>> + igt_install_exit_handler(restore_freq);
> This should be before ..multiprocess_start(), your test may skip
> in case require will trigger skip.
>
> Regards,
> Kamil
sure, I will check this.
Thanks,
Anirban
>
>> igt_require_gem(i915);
>> gem_quiescent_gpu(i915);
>> + intel_allocator_multiprocess_start();
>>
>> i915_for_each_gt(i915, dirfd, gt) {
>> ctx = intel_ctx_create_for_gt(i915, gt);
>> for_each_ctx_engine(i915, ctx, e) {
>> if (e->instance == 0) {
>> igt_dynamic_f("gt%u-%s", gt, e->name)
>> - rc6_idle(i915, ctx->id, e->flags, gt);
>> + rc6_idle(i915, ctx, e->flags, gt);
>> }
>> }
>> intel_ctx_destroy(i915, ctx);
>> }
>> + intel_allocator_multiprocess_stop();
>> }
>>
>> igt_subtest_with_dynamic("rc6-fence") {
>> --
>> 2.34.1
>>
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