From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932177Ab2BAOul (ORCPT ); Wed, 1 Feb 2012 09:50:41 -0500 Received: from mail.betterlinux.com ([199.58.199.50]:40796 "EHLO mail.betterlinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760Ab2BAOuk (ORCPT ); Wed, 1 Feb 2012 09:50:40 -0500 X-Greylist: delayed 420 seconds by postgrey-1.27 at vger.kernel.org; Wed, 01 Feb 2012 09:50:40 EST X-DKIM: OpenDKIM Filter v2.4.1 mail.betterlinux.com 1DCC02341A3 Date: Wed, 1 Feb 2012 15:43:33 +0100 From: Andrea Righi To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Eric Dumazet , Glauber Costa , Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, Russell King - ARM Linux , Paul Tuner Subject: Re: [PATCH] Add num_to_str() for speedup /proc/stat Message-ID: <20120201144333.GA1542@thinkpad> References: <20120124161221.032325d1.akpm@linux-foundation.org> <1327450945.14373.24.camel@edumazet-laptop> <20120124172732.19b3d9f4.akpm@linux-foundation.org> <1327469372.14373.31.camel@edumazet-laptop> <20120125170416.385ee9fa.akpm@linux-foundation.org> <20120126185520.25c8f9b6.kamezawa.hiroyu@jp.fujitsu.com> <20120126164342.a496ded0.akpm@linux-foundation.org> <20120127100933.5e782a33.kamezawa.hiroyu@jp.fujitsu.com> <20120126171800.01c2405c.akpm@linux-foundation.org> <20120130141619.a35863e2.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120130141619.a35863e2.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 --- 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); 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));