From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Andrea Righi <andrea@betterlinux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Glauber Costa <glommer@parallels.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
Paul Tuner <pjt@google.com>
Subject: Re: [PATCH] Add num_to_str() for speedup /proc/stat
Date: Thu, 2 Feb 2012 08:46:30 +0900 [thread overview]
Message-ID: <20120202084630.748aeb67.kamezawa.hiroyu@jp.fujitsu.com> (raw)
In-Reply-To: <20120201144333.GA1542@thinkpad>
On Wed, 1 Feb 2012 15:43:33 +0100
Andrea Righi <andrea@betterlinux.com> wrote:
> On Mon, Jan 30, 2012 at 02:16:19PM +0900, KAMEZAWA Hiroyuki wrote:
> ...
> > diff --git a/fs/proc/stat.c b/fs/proc/stat.c
> > index 121f77c..0ff3b92 100644
> > --- a/fs/proc/stat.c
> > +++ b/fs/proc/stat.c
> > @@ -89,18 +89,19 @@ static int show_stat(struct seq_file *p, void *v)
> > }
> > sum += arch_irq_stat();
> >
> > - seq_printf(p, "cpu %llu %llu %llu %llu %llu %llu %llu %llu %llu "
> > - "%llu\n",
> > - (unsigned long long)cputime64_to_clock_t(user),
> > - (unsigned long long)cputime64_to_clock_t(nice),
> > - (unsigned long long)cputime64_to_clock_t(system),
> > - (unsigned long long)cputime64_to_clock_t(idle),
> > - (unsigned long long)cputime64_to_clock_t(iowait),
> > - (unsigned long long)cputime64_to_clock_t(irq),
> > - (unsigned long long)cputime64_to_clock_t(softirq),
> > - (unsigned long long)cputime64_to_clock_t(steal),
> > - (unsigned long long)cputime64_to_clock_t(guest),
> > - (unsigned long long)cputime64_to_clock_t(guest_nice));
> > + seq_puts(p, "cpu ");
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(system));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(idle));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iowait));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(irq));
> > + seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(softirq));
> > + 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_putc(p, '\n');
> > +
> > for_each_online_cpu(i) {
> > /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
> > user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
> > @@ -113,26 +114,24 @@ static int show_stat(struct seq_file *p, void *v)
> > steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
> > guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
> > guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
> > - seq_printf(p,
> > - "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
> > - "%llu\n",
> > - i,
> > - (unsigned long long)cputime64_to_clock_t(user),
> > - (unsigned long long)cputime64_to_clock_t(nice),
> > - (unsigned long long)cputime64_to_clock_t(system),
> > - (unsigned long long)cputime64_to_clock_t(idle),
> > - (unsigned long long)cputime64_to_clock_t(iowait),
> > - (unsigned long long)cputime64_to_clock_t(irq),
> > - (unsigned long long)cputime64_to_clock_t(softirq),
> > - (unsigned long long)cputime64_to_clock_t(steal),
> > - (unsigned long long)cputime64_to_clock_t(guest),
> > - (unsigned long long)cputime64_to_clock_t(guest_nice));
> > + seq_printf(p, "cpu %d", i);
> ^^^^^^
> mmh... if I'm not wrong this looks like an ABI change.
>
> Thanks,
> -Andrea
>
> ---
> From: Andrea Righi <andrea@betterlinux.com>
> Subject: procfs: avoid breaking the ABI in /proc/stat
>
> The speed up of /proc/stat changed the output of the cpu statistics
> adding an extra space between the string "cpu" and the cpu id.
>
> Restore the old ABI by removing this space.
>
> Signed-off-by: Andrea Righi <andrea@betterlinux.com>
> ---
> fs/proc/stat.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/fs/proc/stat.c b/fs/proc/stat.c
> index 0ff3b92..7ed7efa 100644
> --- a/fs/proc/stat.c
> +++ b/fs/proc/stat.c
> @@ -114,7 +114,7 @@ static int show_stat(struct seq_file *p, void *v)
> steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
> guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
> guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
> - seq_printf(p, "cpu %d", i);
> + seq_printf(p, "cpu%d", i);
Ah, I'm very soory. And thank you very much catching this early !
-Kame
next prev parent reply other threads:[~2012-02-01 23:48 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-20 15:59 [PATCH] proc: speedup /proc/stat handling Eric Dumazet
2012-01-20 22:55 ` Andrew Morton
2012-01-23 10:16 ` KAMEZAWA Hiroyuki
2012-01-23 10:33 ` Glauber Costa
2012-01-24 1:25 ` KAMEZAWA Hiroyuki
2012-01-25 0:01 ` [PATCH v2] " Eric Dumazet
2012-01-25 0:12 ` Andrew Morton
2012-01-25 0:22 ` Eric Dumazet
2012-01-25 1:27 ` Andrew Morton
2012-01-25 5:29 ` Eric Dumazet
2012-01-26 1:04 ` Andrew Morton
2012-01-26 9:55 ` KAMEZAWA Hiroyuki
2012-01-27 0:43 ` Andrew Morton
2012-01-27 1:09 ` KAMEZAWA Hiroyuki
2012-01-27 1:18 ` Andrew Morton
2012-01-30 5:16 ` [PATCH] Add num_to_str() for speedup /proc/stat KAMEZAWA Hiroyuki
2012-01-30 23:20 ` Andrew Morton
2012-01-30 23:58 ` KAMEZAWA Hiroyuki
2012-02-01 14:43 ` Andrea Righi
2012-02-01 23:46 ` KAMEZAWA Hiroyuki [this message]
2012-01-27 7:09 ` [PATCH v2] proc: speedup /proc/stat handling Eric Dumazet
2012-01-25 0:18 ` KAMEZAWA Hiroyuki
2012-01-25 0:26 ` Eric Dumazet
2012-01-30 8:06 ` Jörg-Volker Peetz
2012-01-30 9:25 ` Eric Dumazet
2012-01-30 10:00 ` Jörg-Volker Peetz
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