e7f2be115f
getrusage(RUSAGE_THREAD) with nohz_full may return shorter utime/stime than the actual time. task_cputime_adjusted() snapshots utime and stime and then adjust their sum to match the scheduler maintained cputime.sum_exec_runtime. Unfortunately in nohz_full, sum_exec_runtime is only updated once per second in the worst case, causing a discrepancy against utime and stime that can be updated anytime by the reader using vtime. To fix this situation, perform an update of cputime.sum_exec_runtime when the cputime snapshot reports the task as actually running while the tick is disabled. The related overhead is then contained within the relevant situations. Reported-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Acked-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20211026141055.57358-3-frederic@kernel.org |
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|---|---|---|
| .. | ||
| autogroup.h | ||
| clock.h | ||
| coredump.h | ||
| cpufreq.h | ||
| cputime.h | ||
| deadline.h | ||
| debug.h | ||
| hotplug.h | ||
| idle.h | ||
| init.h | ||
| isolation.h | ||
| jobctl.h | ||
| loadavg.h | ||
| mm.h | ||
| nohz.h | ||
| numa_balancing.h | ||
| prio.h | ||
| rt.h | ||
| sd_flags.h | ||
| signal.h | ||
| smt.h | ||
| stat.h | ||
| sysctl.h | ||
| task.h | ||
| task_stack.h | ||
| topology.h | ||
| types.h | ||
| user.h | ||
| wake_q.h | ||
| xacct.h | ||