Quoting Imre Deak (2020-01-10 16:16:27) > On Thu, Jan 09, 2020 at 10:23:00PM +0000, Chris Wilson wrote: > > Long ago, we would only approach runtime-suspend if the GPU had been > > idle (no userspace submissions) for a second or two. However, since > > disabling automatic HW RC6 such a relaxed approach to runtime-suspend > > caused us to never enter RC6 on the desktop and consume vast quantities > > of power. Surmise this behaviour by setting up a background load that is > > only active for ~1% of the time (so equivalent to a compositor that is > > updating the clock every 50ms or so) and verify that we do continue to > > enter RC6 between the GPU pulses. > > > > References: https://gitlab.freedesktop.org/drm/intel/issues/614 > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Imre Deak <imre.deak@xxxxxxxxx> > > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > --- > > tests/Makefile.am | 1 + > > tests/i915/i915_pm_rc6_residency.c | 174 +++++++++++++++++++++++++++-- > > tests/meson.build | 9 +- > > 3 files changed, 173 insertions(+), 11 deletions(-) > > > > diff --git a/tests/Makefile.am b/tests/Makefile.am > > index 9a320bc23..fc3052475 100644 > > --- a/tests/Makefile.am > > +++ b/tests/Makefile.am > > @@ -122,6 +122,7 @@ gem_threaded_access_tiled_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS) > > gem_threaded_access_tiled_LDADD = $(LDADD) -lpthread > > gem_tiled_swapping_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS) > > gem_tiled_swapping_LDADD = $(LDADD) -lpthread > > +i915_pm_rc6_residency_LDADD = $(LDADD) $(top_builddir)/lib/libigt_perf.la > > prime_self_import_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS) > > prime_self_import_LDADD = $(LDADD) -lpthread > > gem_userptr_blits_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS) > > diff --git a/tests/i915/i915_pm_rc6_residency.c b/tests/i915/i915_pm_rc6_residency.c > > index 1b39c870e..a5bcb084b 100644 > > --- a/tests/i915/i915_pm_rc6_residency.c > > +++ b/tests/i915/i915_pm_rc6_residency.c > > @@ -25,8 +25,6 @@ > > * > > */ > > > > -#include "igt.h" > > -#include "igt_sysfs.h" > > #include <stdio.h> > > #include <stdlib.h> > > #include <string.h> > > @@ -34,6 +32,9 @@ > > #include <errno.h> > > #include <time.h> > > > > +#include "igt.h" > > +#include "igt_perf.h" > > +#include "igt_sysfs.h" > > > > #define SLEEP_DURATION 3 /* in seconds */ > > > > @@ -195,31 +196,180 @@ static bool wait_for_rc6(void) > > return false; > > } > > > > +static uint64_t __pmu_read_single(int fd, uint64_t *ts) > > +{ > > + uint64_t data[2]; > > + > > + igt_assert_eq(read(fd, data, sizeof(data)), sizeof(data)); > > + > > + if (ts) > > + *ts = data[1]; > > + > > + return data[0]; > > +} > > + > > +static uint64_t pmu_read_single(int fd) > > +{ > > + return __pmu_read_single(fd, NULL); > > +} > > + > > +#define __assert_within_epsilon(x, ref, tol_up, tol_down) \ > > + igt_assert_f((double)(x) <= (1.0 + (tol_up)) * (double)(ref) && \ > > + (double)(x) >= (1.0 - (tol_down)) * (double)(ref), \ > > + "'%s' != '%s' (%f not within +%.1f%%/-%.1f%% tolerance of %f)\n",\ > > + #x, #ref, (double)(x), \ > > + (tol_up) * 100.0, (tol_down) * 100.0, \ > > + (double)(ref)) > > + > > +#define assert_within_epsilon(x, ref, tolerance) \ > > + __assert_within_epsilon(x, ref, tolerance, tolerance) > > + > > +static bool __pmu_wait_for_rc6(int fd) > > +{ > > + struct timespec tv = {}; > > + uint64_t start, now; > > + > > + /* First wait for roughly an RC6 Evaluation Interval */ > > + usleep(160 * 1000); > > + > > + /* Then poll for RC6 to start ticking */ > > + now = pmu_read_single(fd); > > + do { > > + start = now; > > + usleep(5000); > > + now = pmu_read_single(fd); > > + if (now - start > 1e6) > > + return true; > > + } while (!igt_seconds_elapsed(&tv)); > > + > > + return false; > > +} > > + > > +static unsigned int measured_usleep(unsigned int usec) > > +{ > > + struct timespec ts = { }; > > + unsigned int slept; > > + > > + slept = igt_nsec_elapsed(&ts); > > + igt_assert(slept == 0); > > + do { > > + usleep(usec - slept); > > + slept = igt_nsec_elapsed(&ts) / 1000; > > + } while (slept < usec); > > + > > + return igt_nsec_elapsed(&ts); > > +} > > + > > +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; > > + > > + fd = perf_i915_open(config); > > + igt_skip_on(fd < 0 && errno == ENODEV); > > + igt_assert(fd >= 0); > > + > > + return fd; > > +} > > + > > +static void rc6_perf(int i915) > > +{ > > + const int64_t duration_ns = 2e9; > > + uint64_t idle, prev, ts[2]; > > + unsigned long slept, cycles; > > + unsigned long *done; > > + int fd; > > + > > + fd = open_pmu(i915, I915_PMU_RC6_RESIDENCY); > > + igt_require(__pmu_wait_for_rc6(fd)); > > + > > + /* While idle check full RC6. */ > > + prev = __pmu_read_single(fd, &ts[0]); > > + slept = measured_usleep(duration_ns / 1000); > > + idle = __pmu_read_single(fd, &ts[1]); > > + igt_debug("slept=%lu perf=%"PRIu64"\n", slept, ts[1] - ts[0]); > > + assert_within_epsilon(idle - prev, ts[1] - ts[0], 5); > > + > > + /* Setup up a very light load */ > > + done = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0); > > + igt_fork(child, 1) { > > + 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, > > + }; > > + > > + do { > > + struct timespec tv = {}; > > + > > + igt_seconds_elapsed(&tv); > > + > > + gem_execbuf(i915, &execbuf); > > + gem_sync(i915, obj.handle); > > + done[1]++; > > + > > + usleep(igt_seconds_elapsed(&tv) / 10); /* => 1% busy */ > > igt_nsec_elapsed()? That's what I thought I wrote. How bizarre! > Not too familiar with the perf interface but I assume event[0] read is > the RC6 residency, while event[1] is the duration while the event was > enabled (so the duration since the event file was opened?). Looks ok: Yup, event[1] is the timestamp, as measured from the start of perf_open. We use PERF_FORMAT_TOTAL_TIME_ENABLED in perf_i915_open(). > Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx> Thanks, -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
