linux-kernel - Re: [PATCH v2] procfs: do not confuse jiffies with cputime64

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 12 Dec 2011 13:43:33 +0100
From:	Michal Hocko <mhocko@...e.cz>
To:	Andreas Schwab <schwab@...ux-m68k.org>
Cc:	Arnd Bergmann <arnd@...db.de>, linux-kernel@...r.kernel.org,
	"Artem S. Tashkinov" <t.artem@...lcity.com>,
	Dave Jones <davej@...hat.com>,
	Alexey Dobriyan <adobriyan@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v2] procfs: do not confuse jiffies with cputime64_t

On Mon 12-12-11 12:51:19, Andreas Schwab wrote:
> get_{idle,iowait}_time are supposed to return cputime64_t values, not
> jiffies.  Add usecs_to_cputime64 for this.

OK, this looks much better than doing an artificial 
us -> ns -> jiffies -> cputime64

Could you also add usecs_to_cputime64 for s390 so that all this is
consistent?

This should cover all architectures AFAICS.

Thanks

> 
> Signed-off-by: Andreas Schwab <schwab@...ux-m68k.org>

Acked-by: Michal Hocko <mhocko@...e.cz>

> ---
>  arch/ia64/include/asm/cputime.h    |    1 +
>  arch/powerpc/include/asm/cputime.h |    2 ++
>  fs/proc/stat.c                     |    4 ++--
>  include/asm-generic/cputime.h      |    1 +
>  4 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/cputime.h b/arch/ia64/include/asm/cputime.h
> index 6073b18..5a274af 100644
> --- a/arch/ia64/include/asm/cputime.h
> +++ b/arch/ia64/include/asm/cputime.h
> @@ -60,6 +60,7 @@ typedef u64 cputime64_t;
>   */
>  #define cputime_to_usecs(__ct)		((__ct) / NSEC_PER_USEC)
>  #define usecs_to_cputime(__usecs)	((__usecs) * NSEC_PER_USEC)
> +#define usecs_to_cputime64(__usecs)	usecs_to_cputime(__usecs)
>  
>  /*
>   * Convert cputime <-> seconds
> diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
> index 33a3580..fa3f921 100644
> --- a/arch/powerpc/include/asm/cputime.h
> +++ b/arch/powerpc/include/asm/cputime.h
> @@ -150,6 +150,8 @@ static inline cputime_t usecs_to_cputime(const unsigned long us)
>  	return ct;
>  }
>  
> +#define usecs_to_cputime64(us)		usecs_to_cputime(us)
> +
>  /*
>   * Convert cputime <-> seconds
>   */
> diff --git a/fs/proc/stat.c b/fs/proc/stat.c
> index 2a30d67..0855e6f 100644
> --- a/fs/proc/stat.c
> +++ b/fs/proc/stat.c
> @@ -32,7 +32,7 @@ static cputime64_t get_idle_time(int cpu)
>  		idle = kstat_cpu(cpu).cpustat.idle;
>  		idle = cputime64_add(idle, arch_idle_time(cpu));
>  	} else
> -		idle = nsecs_to_jiffies64(1000 * idle_time);
> +		idle = usecs_to_cputime64(idle_time);
>  
>  	return idle;
>  }
> @@ -46,7 +46,7 @@ static cputime64_t get_iowait_time(int cpu)
>  		/* !NO_HZ so we can rely on cpustat.iowait */
>  		iowait = kstat_cpu(cpu).cpustat.iowait;
>  	else
> -		iowait = nsecs_to_jiffies64(1000 * iowait_time);
> +		iowait = usecs_to_cputime64(iowait_time);
>  
>  	return iowait;
>  }
> diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h
> index 62ce682..12a1764 100644
> --- a/include/asm-generic/cputime.h
> +++ b/include/asm-generic/cputime.h
> @@ -40,6 +40,7 @@ typedef u64 cputime64_t;
>   */
>  #define cputime_to_usecs(__ct)		jiffies_to_usecs(__ct)
>  #define usecs_to_cputime(__msecs)	usecs_to_jiffies(__msecs)
> +#define usecs_to_cputime64(__msecs)	nsecs_to_jiffies64((__msecs) * 1000)
>  
>  /*
>   * Convert cputime to seconds and back.
> -- 
> 1.7.8
> 
> 
> -- 
> Andreas Schwab, schwab@...ux-m68k.org
> GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
> "And now for something completely different."
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/