[igt-dev] [PATCH i-g-t] test/i915_pm_rc6_residency: Check we enter RC6 when mostly idle
Chris Wilson
chris at chris-wilson.co.uk
Thu Jan 9 22:23:00 UTC 2020
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 at chris-wilson.co.uk>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
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 */
+ } while (!*done);
+ }
+
+ /* While very nearly idle (idle to within tolerance), except full RC6 */
+ cycles = -done[1];
+ prev = __pmu_read_single(fd, &ts[0]);
+ slept = measured_usleep(duration_ns / 1000);
+ idle = __pmu_read_single(fd, &ts[1]);
+ cycles += done[1];
+ igt_debug("slept=%lu perf=%"PRIu64", cycles=%lu\n",
+ slept, ts[1] - ts[0], cycles);
+ igt_assert(cycles > 0);
+ assert_within_epsilon(idle - prev, ts[1] - ts[0], 5);
+
+ close(fd);
+
+ *done = 1;
+ igt_waitchildren();
+}
+
igt_main
{
unsigned int rc6_enabled = 0;
unsigned int devid = 0;
+ int i915 = -1;
/* Use drm_open_driver to verify device existence */
igt_fixture {
- int fd;
-
- fd = drm_open_driver(DRIVER_INTEL);
- devid = intel_get_drm_devid(fd);
- sysfs = igt_sysfs_open(fd);
+ i915 = drm_open_driver(DRIVER_INTEL);
+ devid = intel_get_drm_devid(i915);
+ sysfs = igt_sysfs_open(i915);
igt_require(has_rc6_residency("rc6"));
/* Make sure rc6 counters are running */
- igt_drop_caches_set(fd, DROP_IDLE);
+ igt_drop_caches_set(i915, DROP_IDLE);
igt_require(wait_for_rc6());
- close(fd);
-
rc6_enabled = get_rc6_enabled_mask();
igt_require(rc6_enabled & RC6_ENABLED);
}
+ igt_subtest("rc6-perf") {
+ igt_require_gem(i915);
+ gem_quiescent_gpu(i915);
+
+ rc6_perf(i915);
+ }
+
igt_subtest("rc6-accuracy") {
struct residencies res;
@@ -235,4 +385,8 @@ igt_main
measure_residencies(devid, rc6_enabled, &res);
residency_accuracy(res.media_rc6, res.duration, "media_rc6");
}
+
+ igt_fixture
+ close(i915);
+
}
diff --git a/tests/meson.build b/tests/meson.build
index 570de5459..a79d22ba1 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -232,7 +232,6 @@ i915_progs = [
'i915_module_load',
'i915_pm_backlight',
'i915_pm_lpsp',
- 'i915_pm_rc6_residency',
'i915_pm_rpm',
'i915_pm_dc',
'i915_pm_rps',
@@ -336,6 +335,14 @@ test_executables += executable('gem_mmap_offset',
install : true)
test_list += 'gem_mmap_offset'
+test_executables += executable('i915_pm_rc6_residency',
+ join_paths('i915', 'i915_pm_rc6_residency.c'),
+ dependencies : test_deps + [ lib_igt_perf ],
+ install_dir : libexecdir,
+ install_rpath : libexecdir_rpathdir,
+ install : true)
+test_list += 'i915_pm_rc6_residency'
+
test_executables += executable('perf_pmu', 'perf_pmu.c',
dependencies : test_deps + [ lib_igt_perf ],
install_dir : libexecdir,
--
2.25.0.rc2
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