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From: Ralf Baechle <ralf@linux-mips.org>
To: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: linux-mips@linux-mips.org
Subject: Re: [MIPS] Fix and cleanup the MIPS part of the (ab)use of CLOCK_TICK_RATE.
Date: Wed, 7 Nov 2007 14:17:57 +0000	[thread overview]
Message-ID: <20071107141757.GB1022@linux-mips.org> (raw)
In-Reply-To: <20071107.231036.75185559.anemo@mba.ocn.ne.jp>

On Wed, Nov 07, 2007 at 11:10:36PM +0900, Atsushi Nemoto wrote:

> The CLOCK_TICK_RATE is used for ACTHZ, TICK_NSEC, etc.
> 
> At least for i8253-free platforms, It looks a value multiple of HZ
> would be better for such constants, assuming we have dyntick or
> accurate HZ clockevents.
> 
> How about something like this?
> 
> diff --git a/include/asm-mips/timex.h b/include/asm-mips/timex.h
> index 5816ad1..e9622b6 100644
> --- a/include/asm-mips/timex.h
> +++ b/include/asm-mips/timex.h
> @@ -18,7 +18,11 @@
>   * So keeping it defined to the number for the PIT is the only sane thing
>   * for now.
>   */
> +#ifdef CONFIG_I8253
>  #define CLOCK_TICK_RATE 1193182
> +#else
> +#define CLOCK_TICK_RATE 1024000	/* multiple of HZ */
> +#endif

kernel/time/ntp.c:#define CLOCK_TICK_OVERFLOW   (LATCH * HZ - CLOCK_TICK_RATE)
kernel/time/ntp.c:                                      (s64)CLOCK_TICK_RATE)

drivers/char/vt_ioctl.c:                        arg = CLOCK_TICK_RATE / arg;
drivers/char/vt_ioctl.c:                        count = CLOCK_TICK_RATE / count;

There is so much abuse of this variable, it's not even funny.  It really
deserve to be taken out and shot.  And that's just two cases.

  Ralf

      reply	other threads:[~2007-11-07 14:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <S20025770AbXKAPqq/20071101154646Z+4363@ftp.linux-mips.org>
2007-11-07 14:10 ` [MIPS] Fix and cleanup the MIPS part of the (ab)use of CLOCK_TICK_RATE Atsushi Nemoto
2007-11-07 14:17   ` Ralf Baechle [this message]

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