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| author |   Frederic Weisbecker <frederic@kernel.org> | 2023-02-22 15:46:48 +0100 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2023-04-18 16:35:13 +0200 |
| commit | 270b2a679ea7be1ee2d84ea67751fb1ab15bcb20 (patch) | |
| tree | 99e1548b39733ace5a349aab7b60ccb89eb71bd3 /tools/testing/selftests/proc/proc-uptime-001.c | |
| parent | MAINTAINERS: Remove stale email address (diff) | |
| download | wireguard-linux-270b2a679ea7be1ee2d84ea67751fb1ab15bcb20.tar.xz wireguard-linux-270b2a679ea7be1ee2d84ea67751fb1ab15bcb20.zip | |
selftests/proc: Remove idle time monotonicity assertions
Due to broken iowait task counting design (cf: comments above
get_cpu_idle_time_us() and nr_iowait()), it is not possible to provide
the guarantee that /proc/stat or /proc/uptime display monotonic idle
time values.
Remove the assertions that verify the related wrong assumption so that
testers and maintainers don't spend more time on that.
Reported-by: Yu Liao <liaoyu15@huawei.com>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230222144649.624380-8-frederic@kernel.org
Diffstat (limited to 'tools/testing/selftests/proc/proc-uptime-001.c')
| -rw-r--r-- | tools/testing/selftests/proc/proc-uptime-001.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/tools/testing/selftests/proc/proc-uptime-001.c b/tools/testing/selftests/proc/proc-uptime-001.c index 781f7a50fc3f..35bddd9dd60b 100644 --- a/tools/testing/selftests/proc/proc-uptime-001.c +++ b/tools/testing/selftests/proc/proc-uptime-001.c @@ -13,7 +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 values in /proc/uptime increment monotonically. +// 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() #undef NDEBUG #include <assert.h> #include <stdint.h> @@ -25,20 +27,18 @@ int main(void) { - uint64_t start, u0, u1, i0, i1; + uint64_t start, u0, u1; int fd; fd = open("/proc/uptime", O_RDONLY); assert(fd >= 0); - proc_uptime(fd, &u0, &i0); + u0 = proc_uptime(fd); start = u0; do { - proc_uptime(fd, &u1, &i1); + u1 = proc_uptime(fd); assert(u1 >= u0); - assert(i1 >= i0); u0 = u1; - i0 = i1; } while (u1 - start < 100); return 0; |