On Thu, Jun 25, 2026 at 04:20:25PM -0400, Joe Simmons-Talbott wrote: > On Thu, Jun 25, 2026 at 3:54 PM Joe Simmons-Talbott <[email protected]> wrote: > > > > +mailing lists > +Tao Cui
I messed this up. Please ignore this patch. I will resend. Thanks, Joe > > > > > For lower HZ values a quota of 1000us is much lower than the amount > > of microseconds per tick which makes the tests test_cpucg_max and > > test_cpugc_max_nested fail. Increase the test duration to accommodate > > for lower HZ values. > > > > Link: https://lore.kernel.org/lkml/[email protected]/ > > Signed-off-by: Joe Simmons-Talbott <[email protected]> > > --- > > v3 -> v4: > > - Use usec for adjusting test duration for better accuracy. > > - Remove underscore from static function > > - Use 1000 as the fallback value for hz since it's the default. > > > > v2 -> v3: > > - Instead of changing cpu.max quota extend the test duration based on > > the HZ value. > > - don't call pclose() if popen() fails. > > - check return value of fscanf(). > > > > v1 -> v2: > > - Try checking /proc/config.gz to get the actual kernel HZ value and > > fallback to 1000 if the value cannot be determined. > > > > .../cgroup/lib/include/cgroup_util.h | 1 + > > tools/testing/selftests/cgroup/test_cpu.c | 47 ++++++++++++++++--- > > 2 files changed, 42 insertions(+), 6 deletions(-) > > > > diff --git a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h > > b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h > > index febc1723d090..8ebb2b4d4ec0 100644 > > --- a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h > > +++ b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h > > @@ -8,6 +8,7 @@ > > > > #define MB(x) (x << 20) > > > > +#define NSEC_PER_USEC 1000L > > #define USEC_PER_SEC 1000000L > > #define NSEC_PER_SEC 1000000000L > > > > diff --git a/tools/testing/selftests/cgroup/test_cpu.c > > b/tools/testing/selftests/cgroup/test_cpu.c > > index 7a40d76b9548..1f280c1db68a 100644 > > --- a/tools/testing/selftests/cgroup/test_cpu.c > > +++ b/tools/testing/selftests/cgroup/test_cpu.c > > @@ -639,6 +639,31 @@ test_cpucg_nested_weight_underprovisioned(const char > > *root) > > return run_cpucg_nested_weight_test(root, false); > > } > > > > +/* > > + * Best effort attempt to get the kernel's HZ value from the config. > > + * Return the HZ value if found otherwise return 1000 (the default) to > > + * indicate failure. > > + */ > > +static long > > +get_config_hz(void) > > +{ > > + long hz = 1000; > > + FILE *f; > > + char cmd[256] = "zcat /proc/config.gz 2>/dev/null | grep > > '^CONFIG_HZ='"; > > + > > + f = popen(cmd, "r"); > > + > > + if (!f) > > + return hz; > > + > > + if (fscanf(f, "CONFIG_HZ=%ld", &hz) == EOF) > > + goto out; > > + > > +out: > > + pclose(f); > > + return hz; > > +} > > + > > /* > > * This test creates a cgroup with some maximum value within a period, and > > * verifies that a process in the cgroup is not overscheduled. > > @@ -646,15 +671,20 @@ test_cpucg_nested_weight_underprovisioned(const char > > *root) > > static int test_cpucg_max(const char *root) > > { > > int ret = KSFT_FAIL; > > + long hz = get_config_hz(); > > long quota_usec = 1000; > > long default_period_usec = 100000; /* cpu.max's default period */ > > long duration_seconds = 1; > > > > - long duration_usec = duration_seconds * USEC_PER_SEC; > > + long duration_usec, duration_sec, duration_nsec; > > long usage_usec, n_periods, remainder_usec, expected_usage_usec; > > char *cpucg; > > char quota_buf[32]; > > > > + duration_usec = duration_seconds * USEC_PER_SEC * 1000 / hz; > > + duration_sec = duration_usec / USEC_PER_SEC; > > + duration_nsec = duration_usec % USEC_PER_SEC * NSEC_PER_USEC; > > + > > snprintf(quota_buf, sizeof(quota_buf), "%ld", quota_usec); > > > > cpucg = cg_name(root, "cpucg_test"); > > @@ -670,8 +700,8 @@ static int test_cpucg_max(const char *root) > > struct cpu_hog_func_param param = { > > .nprocs = 1, > > .ts = { > > - .tv_sec = duration_seconds, > > - .tv_nsec = 0, > > + .tv_sec = duration_sec, > > + .tv_nsec = duration_nsec, > > }, > > .clock_type = CPU_HOG_CLOCK_WALL, > > }; > > @@ -710,15 +740,20 @@ static int test_cpucg_max(const char *root) > > static int test_cpucg_max_nested(const char *root) > > { > > int ret = KSFT_FAIL; > > + long hz = get_config_hz(); > > long quota_usec = 1000; > > long default_period_usec = 100000; /* cpu.max's default period */ > > long duration_seconds = 1; > > > > - long duration_usec = duration_seconds * USEC_PER_SEC; > > + long duration_usec, duration_sec, duration_nsec; > > long usage_usec, n_periods, remainder_usec, expected_usage_usec; > > char *parent, *child; > > char quota_buf[32]; > > > > + duration_usec = duration_seconds * USEC_PER_SEC * 1000 / hz; > > + duration_sec = duration_usec / USEC_PER_SEC; > > + duration_nsec = duration_usec % USEC_PER_SEC * NSEC_PER_USEC; > > + > > snprintf(quota_buf, sizeof(quota_buf), "%ld", quota_usec); > > > > parent = cg_name(root, "cpucg_parent"); > > @@ -741,8 +776,8 @@ static int test_cpucg_max_nested(const char *root) > > struct cpu_hog_func_param param = { > > .nprocs = 1, > > .ts = { > > - .tv_sec = duration_seconds, > > - .tv_nsec = 0, > > + .tv_sec = duration_sec, > > + .tv_nsec = duration_nsec, > > }, > > .clock_type = CPU_HOG_CLOCK_WALL, > > }; > > -- > > 2.54.0 > >
