RE: [RFC] proc: change /proc/stat show

["Wang, Yalin" <Yalin.Wang@sonymobile.com>]

> -----Original Message-----
> From: David Rientjes [mailto:rientjes@google.com]
> Sent: Wednesday, March 18, 2015 7:02 AM
> To: Wang, Yalin
> Cc: akpm@linux-foundation.org; heiko.carstens@de.ibm.com;
> tglx@linutronix.de; linux-kernel@vger.kernel.org
> Subject: Re: [RFC] proc: change /proc/stat show
> 
> On Tue, 17 Mar 2015, Wang, Yalin wrote:
> 
> > diff --git a/fs/proc/stat.c b/fs/proc/stat.c
> > index 510413eb..60b39e2 100644
> > --- a/fs/proc/stat.c
> > +++ b/fs/proc/stat.c
> > @@ -130,7 +130,7 @@ static int show_stat(struct seq_file *p, void *v)
> >  	seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
> >  	seq_putc(p, '\n');
> >
> > -	for_each_online_cpu(i) {
> > +	for_each_present_cpu(i) {
> >  		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
> >  		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
> >  		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
> > @@ -153,6 +153,7 @@ static int show_stat(struct seq_file *p, void *v)
> >  		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
> >  		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
> >  		seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
> > +		seq_printf(p, " %d", cpu_online(i)? 1 : 0);
> >  		seq_putc(p, '\n');
> >  	}
> >  	seq_printf(p, "intr %llu", (unsigned long long)sum);
> 
> Makes sense, but why do we need to output the cpu state as part of
> /proc/stat?  This information should already be available elsewhere.
Yeah,  online / offline info can be read from /sys/devices/cpu .
I can remove this line , if you think it is not needed .

Thanks