From 263dda24fff0957f6b0a9abde2809122f7f0fad8 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Feb 2023 15:46:49 +0100 Subject: selftests/proc: Assert clock_gettime(CLOCK_BOOTTIME) VS /proc/uptime monotonicity The first field of /proc/uptime relies on the CLOCK_BOOTTIME clock which can also be fetched from clock_gettime() API. Improve the test coverage while verifying the monotonicity of CLOCK_BOOTTIME accross both interfaces. Suggested-by: Thomas Gleixner Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230222144649.624380-9-frederic@kernel.org --- tools/testing/selftests/proc/proc-uptime-001.c | 21 +++++++++++++++++---- tools/testing/selftests/proc/proc-uptime-002.c | 22 ++++++++++++++++++---- tools/testing/selftests/proc/proc-uptime.h | 12 ++++++++++++ 3 files changed, 47 insertions(+), 8 deletions(-) (limited to 'tools/testing/selftests/proc') diff --git a/tools/testing/selftests/proc/proc-uptime-001.c b/tools/testing/selftests/proc/proc-uptime-001.c index 35bddd9dd60b..f335eec5067e 100644 --- a/tools/testing/selftests/proc/proc-uptime-001.c +++ b/tools/testing/selftests/proc/proc-uptime-001.c @@ -13,9 +13,9 @@ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ -// Test that boottime value in /proc/uptime increments monotonically. -// We don't test idle time monotonicity due to broken iowait task -// counting, cf: comment above get_cpu_idle_time_us() +// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment +// monotonically. We don't test idle time monotonicity due to broken iowait +// task counting, cf: comment above get_cpu_idle_time_us() #undef NDEBUG #include #include @@ -27,7 +27,7 @@ int main(void) { - uint64_t start, u0, u1; + uint64_t start, u0, u1, c0, c1; int fd; fd = open("/proc/uptime", O_RDONLY); @@ -35,10 +35,23 @@ int main(void) u0 = proc_uptime(fd); start = u0; + c0 = clock_boottime(); + do { u1 = proc_uptime(fd); + c1 = clock_boottime(); + + /* Is /proc/uptime monotonic ? */ assert(u1 >= u0); + + /* Is CLOCK_BOOTTIME monotonic ? */ + assert(c1 >= c0); + + /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */ + assert(c0 >= u0); + u0 = u1; + c0 = c1; } while (u1 - start < 100); return 0; diff --git a/tools/testing/selftests/proc/proc-uptime-002.c b/tools/testing/selftests/proc/proc-uptime-002.c index 7ad79d5eaa84..ae453daa96c1 100644 --- a/tools/testing/selftests/proc/proc-uptime-002.c +++ b/tools/testing/selftests/proc/proc-uptime-002.c @@ -13,9 +13,10 @@ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ -// Test that boottime value in /proc/uptime increments monotonically -// while shifting across CPUs. We don't test idle time monotonicity -// due to broken iowait task counting, cf: comment above get_cpu_idle_time_us() +// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment +// monotonically while shifting across CPUs. We don't test idle time +// monotonicity due to broken iowait task counting, cf: comment above +// get_cpu_idle_time_us() #undef NDEBUG #include #include @@ -43,10 +44,10 @@ static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned lo int main(void) { + uint64_t u0, u1, c0, c1; unsigned int len; unsigned long *m; unsigned int cpu; - uint64_t u0, u1; int fd; /* find out "nr_cpu_ids" */ @@ -62,6 +63,8 @@ int main(void) assert(fd >= 0); u0 = proc_uptime(fd); + c0 = clock_boottime(); + for (cpu = 0; cpu < len * 8; cpu++) { memset(m, 0, len); m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long))); @@ -70,8 +73,19 @@ int main(void) sys_sched_setaffinity(0, len, m); u1 = proc_uptime(fd); + c1 = clock_boottime(); + + /* Is /proc/uptime monotonic ? */ assert(u1 >= u0); + + /* Is CLOCK_BOOTTIME monotonic ? */ + assert(c1 >= c0); + + /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */ + assert(c0 >= u0); + u0 = u1; + c0 = c1; } return 0; diff --git a/tools/testing/selftests/proc/proc-uptime.h b/tools/testing/selftests/proc/proc-uptime.h index ca55abeb0ccc..730cce4a3d73 100644 --- a/tools/testing/selftests/proc/proc-uptime.h +++ b/tools/testing/selftests/proc/proc-uptime.h @@ -19,9 +19,21 @@ #include #include #include +#include #include "proc.h" +static uint64_t clock_boottime(void) +{ + struct timespec ts; + int err; + + err = clock_gettime(CLOCK_BOOTTIME, &ts); + assert(err >= 0); + + return (ts.tv_sec * 100) + (ts.tv_nsec / 10000000); +} + static uint64_t proc_uptime(int fd) { uint64_t val1, val2; -- cgit v1.2.3