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Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs

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On Mon, Jan 30, 2017 at 03:56:49PM +0100, Frederic Weisbecker wrote:
> On Mon, Jan 30, 2017 at 03:32:24PM +0100, Stanislaw Gruszka wrote:
> > On Mon, Jan 30, 2017 at 05:46:43AM +0100, Frederic Weisbecker wrote:
> > > Now lets admit one drawback: s390 and powerpc with
> > > CONFIG_VIRT_CPU_ACCOUNTING_NATIVE have new cputime_t to nsecs conversion
> > > on cputime accounting path. But this should be leveraged by the recent
> > > changes which delay the cputime accounting to tick and context switch. 
> > 
> > I think it would be worth to mention that there are other drawbacks on
> > 32bit architectures that use cputime-jiffies currently, like:
> > - cache utilization will be worse
> 
> Due to utime and stime becoming 64 bits? Yeah indeed.

:-) Well, it is possible that something that use to fit into one cache
line, now will be consuming 2 cache lines and results more cache misses.

In general, this patchset seems to be nice cleanup of code, but how it
affect runtime efficiency is not clear and might depend on .config
and architecture. However seems 32bit embedded users will be affected
negatively.

Stanislaw

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[GIT PULL] cputime: Convert core use of cputime_t to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-30 05:50 +0100
  Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Stanislaw Gruszka <sgruszka@redhat.com> - 2017-01-30 15:40 +0100
    Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-30 16:10 +0100
      Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Stanislaw Gruszka <sgruszka@redhat.com> - 2017-01-30 17:00 +0100
  [PATCH RESEND 01/36] jiffies: Reuse TICK_NSEC instead of NSEC_PER_JIFFY Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:20 +0100
    [PATCH RESEND 04/36] cputime: Convert kcpustat to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] sched/cputime: Convert kcpustat to nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 24/36] cputime: Push time to account_idle_time() in nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] sched/cputime: Push time to account_idle_time() in  nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 25/36] cputime: Push time to account_system_time() in nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] sched/cputime: Push time to account_system_time()  in nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 16/36] signal: Convert obsolete cputime type to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] signal: Convert obsolete cputime type to nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 27/36] vtime: Return nsecs instead of cputime_t to account Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] sched/cputime, vtime: Return nsecs instead of  cputime_t to account tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 09/36] alpha: Convert obsolete cputime_t to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] alpha: Convert obsolete cputime_t to nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 12/36] binfmt: Convert obsolete cputime type to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:30 +0100
      [tip:sched/core] fs/binfmt: Convert obsolete cputime type to nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 30/36] ia64: Convert vtime to use nsec units directly Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:40 +0100
      [tip:sched/core] ia64: Convert vtime to use nsec units directly tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 05/36] macintosh/rack-meter: Remove cputime_t internal use Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:40 +0100
      [tip:sched/core] macintosh/rack-meter: Convert cputime64_t use to  u64 tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 12:00 +0100
    [PATCH RESEND 07/36] cputime: Special API to return old-typed cputime Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:40 +0100
      [tip:sched/core] sched/cputime: Introduce special task_cputime_t()  API to return old-typed cputime tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 02/36] time: Introduce jiffies64_to_nsecs() Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:50 +0100
      [tip:sched/core] time: Introduce jiffies64_to_nsecs() tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 26/36] cputime: Complete nsec conversion of tick based accounting Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:50 +0100
      [tip:sched/core] sched/cputime: Complete nsec conversion of tick  based accounting tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 17/36] cputime: Increment kcpustat directly on irqtime account Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 04:50 +0100
      [tip:sched/core] sched/cputime: Increment kcpustat directly on  irqtime account tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [PATCH RESEND 10/36] x86: Convert obsolete cputime type to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 05:20 +0100
      [tip:sched/core] x86: Convert obsolete cputime type to nsecs tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
    [PATCH RESEND 33/36] powerpc: Remove unused cputime definitions Frederic Weisbecker <fweisbec@gmail.com> - 2017-01-31 05:30 +0100
      [tip:sched/core] powerpc, sched/cputime: Remove unused cputime  definitions tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:10 +0100
    [tip:sched/core] jiffies: Reuse TICK_NSEC instead of NSEC_PER_JIFFY tip-bot for Frederic Weisbecker <tipbot@zytor.com> - 2017-02-01 11:00 +0100
  Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-02-06 14:50 +0100
    Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Ingo Molnar <mingo@kernel.org> - 2017-02-07 09:10 +0100
      Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Frederic Weisbecker <fweisbec@gmail.com> - 2017-02-07 15:10 +0100
        Re: [GIT PULL] cputime: Convert core use of cputime_t to nsecs Ingo Molnar <mingo@kernel.org> - 2017-02-07 20:00 +0100

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