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    SubjectRe: [PATCH 1/7] posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
    From
    2013/5/7 KOSAKI Motohiro <kosaki.motohiro@gmail.com>:
    >>> + /*
    >>> + * After turning over se.sum_exec_runtime to sig->sum_sched_runtime
    >>> + * in __exit_signal(), we must not account exec_runtime for consistency.
    >>> + */
    >>> + if (unlikely(!tsk->sighand))
    >>> + return;
    >>
    >> Ok, if we want the clock and timer to be consistent, do we also want the same check in
    >> account_group_user_time() and account_group_system_time()? The task can still account
    >> a tick after autoreaping itself between release_task() and the final schedule().
    >
    > You are right.
    >
    > That said, current the man pages don't describe this linux specific
    > extensions. So, nobody
    > (glibc, ltp, and me) tested them. Please give me a couple of days.
    > I'll test and fix this features
    > too.
    >
    > timer_create(2): http://man7.org/linux/man-pages/man2/timer_create.2.html

    Ah, indeed timer_create() seem to only create CPUCLOCK_SCHED timers. So that
    issue with timer_gettime becoming asynchonous with clock_gettime can't happen
    with PROF and VIRT clocks

    I see itimers can use those clocks. But there don't seem to be a
    similar issue with
    getitimer/setitimer as they don't have matching clock reads.

    Thanks.


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