From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753774Ab1LUT7X (ORCPT ); Wed, 21 Dec 2011 14:59:23 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59541 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348Ab1LUT7U (ORCPT ); Wed, 21 Dec 2011 14:59:20 -0500 Date: Wed, 21 Dec 2011 11:59:19 -0800 From: Andrew Morton To: Michal Hocko Cc: Arnd Bergmann , linux-kernel@vger.kernel.org, "Artem S. Tashkinov" , Dave Jones , Alexey Dobriyan , Thomas Gleixner , Andreas Schwab , Martin Schwidefsky Subject: Re: [resend PATCH for 3.2] procfs: do not confuse jiffies with cputime64_t Message-Id: <20111221115919.6beac46f.akpm@linux-foundation.org> In-Reply-To: <20111221100334.GD27137@tiehlicka.suse.cz> References: <201112120922.13633.arnd@arndb.de> <20111212124333.GC14720@tiehlicka.suse.cz> <20111212131218.GD14720@tiehlicka.suse.cz> <20111221100334.GD27137@tiehlicka.suse.cz> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 Dec 2011 11:03:34 +0100 Michal Hocko wrote: > Hmm, it seems that this bugfix (for 3.2) stalled. I guess that it is > primarily because it is multiarch fix. > I am sorry to bother you Andrew but could we push this through you, > please? > > The full patch for reference: > --- > >From 1fca39b21f3b344c90c30d98db6dcdcdc6815797 Mon Sep 17 00:00:00 2001 > From: Andreas Schwab > Date: Mon, 12 Dec 2011 14:07:53 +0100 > Subject: [PATCH] procfs: do not confuse jiffies with cputime64_t > > get_{idle,iowait}_time are supposed to return cputime64_t values, not > jiffies. Add usecs_to_cputime64 for this. This makes a huge mess when mixed with Martin's "cputime: add sparse checking and cleanup" in linux-next. I think I got it fixed up but it needs careful checking - I don't _think_ I needed to add more __force thingies. The version against today's linux-next is below. (I did party tricks with this so I could carry the against-mainline and against-next versions in the same tree). Also, in include/asm-generic/cputime.h we have: #define usecs_to_cputime64(__msecs) nsecs_to_jiffies64((__msecs) * 1000) But it would be neater to have used nsecs_to_cputime64(), surely. Also, the changelog still sucks From: Andreas Schwab Subject: procfs: do not confuse jiffies with cputime64_t get_{idle,iowait}_time are supposed to return cputime64_t values, not jiffies. Add usecs_to_cputime64 for this. Signed-off-by: Andreas Schwab Acked-by: Michal Hocko Cc: Arnd Bergmann Cc: "Artem S. Tashkinov" Cc: Dave Jones Cc: Alexey Dobriyan Cc: Thomas Gleixner Cc: "Luck, Tony" Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton --- arch/ia64/include/asm/cputime.h | 1 + arch/powerpc/include/asm/cputime.h | 2 ++ arch/s390/include/asm/cputime.h | 2 ++ fs/proc/stat.c | 4 ++-- include/asm-generic/cputime.h | 1 + 5 files changed, 8 insertions(+), 2 deletions(-) diff -puN arch/ia64/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t arch/ia64/include/asm/cputime.h --- a/arch/ia64/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t +++ a/arch/ia64/include/asm/cputime.h @@ -50,6 +50,7 @@ typedef u64 __nocast cputime64_t; ((__force u64)(__ct) / NSEC_PER_USEC) #define usecs_to_cputime(__usecs) \ (__force cputime_t)((__usecs) * NSEC_PER_USEC) +#define usecs_to_cputime64(__usecs) usecs_to_cputime(__usecs) /* * Convert cputime <-> seconds diff -puN arch/powerpc/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t arch/powerpc/include/asm/cputime.h --- a/arch/powerpc/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t +++ a/arch/powerpc/include/asm/cputime.h @@ -134,6 +134,8 @@ static inline cputime_t usecs_to_cputime return (__force cputime_t) ct; } +#define usecs_to_cputime64(us) usecs_to_cputime(us) + /* * Convert cputime <-> seconds */ diff -puN arch/s390/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t arch/s390/include/asm/cputime.h --- a/arch/s390/include/asm/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t +++ a/arch/s390/include/asm/cputime.h @@ -72,6 +72,8 @@ static inline cputime_t usecs_to_cputime return (__force cputime_t)(m * 4096ULL); } +#define usecs_to_cputime64(m) usecs_to_cputime(m) + /* * Convert cputime to milliseconds and back. */ diff -puN fs/proc/stat.c~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t fs/proc/stat.c --- a/fs/proc/stat.c~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t +++ a/fs/proc/stat.c @@ -31,7 +31,7 @@ static u64 get_idle_time(int cpu) idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]; idle += arch_idle_time(cpu); } else - idle = nsecs_to_jiffies64(1000 * idle_time); + idle = usecs_to_cputime64(idle_time); return idle; } @@ -44,7 +44,7 @@ static u64 get_iowait_time(int cpu) /* !NO_HZ so we can rely on cpustat.iowait */ iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; else - iowait = nsecs_to_jiffies64(1000 * iowait_time); + iowait = usecs_to_cputime64(iowait_time); return iowait; } diff -puN include/asm-generic/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t include/asm-generic/cputime.h --- a/include/asm-generic/cputime.h~reapply-procfs-do-not-confuse-jiffies-with-cputime64_t +++ a/include/asm-generic/cputime.h @@ -27,6 +27,7 @@ typedef u64 __nocast cputime64_t; jiffies_to_usecs(cputime_to_jiffies(__ct)); #define usecs_to_cputime(__msecs) \ jiffies_to_cputime(usecs_to_jiffies(__msecs)); +#define usecs_to_cputime64(__msecs) nsecs_to_jiffies64((__msecs) * 1000) /* * Convert cputime to seconds and back. _ .