On Thu, 2007-07-19 at 21:38 +0200, Ingo Molnar wrote: > * Jan Glauber <[EMAIL PROTECTED]> wrote: > > > > still, CFS needs time measurement across idle periods as well, for > > > another purpose: to be able to do precise task statistics for /proc. > > > (for top, ps, etc.) So it's still true that sched_clock() should > > > include idle periods too. > > > > I'm not sure, s390 already has an implemetation for precise accounting > > in the architecture code, does CFS also improve accounting data? > > what kind of precise accounting does s390 have in the architecture code? > CFS changes task (and load) accounting to be sched_clock() driven in > essence.
s390 has per-process accounting that is aware of virtual cpu time, implemented in arch/s390/kernel/time.c: account_ticks() and arch/s390/kernel/vtime.c: account_*_vtime(). Timestamps are taken in entry.S for system calls, interrupts and other system entries and are accounted later, we don't call update_process_times(). Jan > Ingo > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
