Re: [PATCH] proc/schedstat: Expose /proc/<pid>/schedstat if delay accounting is enabled

["Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>]

On 2015/05/28 02:41PM, Balbir Singh wrote:
> On Mon, May 25, 2015 at 12:42 PM, Naveen N. Rao
> <naveen.n.rao@linux.vnet.ibm.com> wrote:
> > /proc/<pid>/schedstat is currently only available if CONFIG_SCHEDSTATS is
> > enabled. But, all the fields that this exposes are available and valid
> > if CONFIG_TASK_DELAY_ACCT is enabled as well.
> >
> > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> > ---
> >  fs/proc/base.c | 11 +++++++----
> >  1 file changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/proc/base.c b/fs/proc/base.c
> > index 093ca14..3ece303 100644
> > --- a/fs/proc/base.c
> > +++ b/fs/proc/base.c
> > @@ -304,14 +304,17 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
> >  }
> >  #endif
> >
> > -#ifdef CONFIG_SCHEDSTATS
> > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
> >  /*
> >   * Provides /proc/PID/schedstat
> >   */
> >  static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
> >                               struct pid *pid, struct task_struct *task)
> >  {
> > -       seq_printf(m, "%llu %llu %lu\n",
> > +       if (unlikely(!sched_info_on()))
> > +               seq_printf(m, "0 0 0\n");
> > +       else
> > +               seq_printf(m, "%llu %llu %lu\n",
> >                    (unsigned long long)task->se.sum_exec_runtime,
> >                    (unsigned long long)task->sched_info.run_delay,
> >                    task->sched_info.pcount);
> > @@ -2600,7 +2603,7 @@ static const struct pid_entry tgid_base_stuff[] = {
> >  #ifdef CONFIG_STACKTRACE
> >         ONE("stack",      S_IRUSR, proc_pid_stack),
> >  #endif
> > -#ifdef CONFIG_SCHEDSTATS
> > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
> >         ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
> >  #endif
> >  #ifdef CONFIG_LATENCYTOP
> > @@ -2948,7 +2951,7 @@ static const struct pid_entry tid_base_stuff[] = {
> >  #ifdef CONFIG_STACKTRACE
> >         ONE("stack",      S_IRUSR, proc_pid_stack),
> >  #endif
> > -#ifdef CONFIG_SCHEDSTATS
> > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
> >         ONE("schedstat", S_IRUGO, proc_pid_schedstat),
> >  #endif
> >  #ifdef CONFIG_LATENCYTOP
> > --
> 
> The change looks reasonable, from what I can understand you want these
> changes so that you can use /proc/<pid>/schedstat instead of the
> netlink interface when CONFIG_TASK_DELAY_ACCT is enabled.
> 
> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> 

Yes, thanks for the review, Balbir!

Ingo,
Can you please pick this up?


Regards,
Naveen