Re: [patch] x86_64: fix sched_clock()

[Andi Kleen <andi@firstfloor.org>]

> This?    I sent it to you earlier this week:

Sorry haven't processed those yet.

Ah. The correct fix here is to clear the tsc flag in boot_cpu_data
when the option is set. Will do that.

-Andi


> 
> From: Rusty Russell <rusty@rustcorp.com.au>
> 
> If you set tsc_disable (eg "notsc" on cmdline), sched-clock.c gives a
> divide by zero on boot.
> 
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Andi Kleen <ak@suse.de>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  arch/i386/kernel/sched-clock.c |    2 +-
>  1 files changed, 1 insertion(+), 1 deletion(-)
> 
> diff -puN arch/i386/kernel/sched-clock.c~fix-x86_64-mm-sched-clock-share arch/i386/kernel/sched-clock.c
> --- a/arch/i386/kernel/sched-clock.c~fix-x86_64-mm-sched-clock-share
> +++ a/arch/i386/kernel/sched-clock.c
> @@ -115,7 +115,7 @@ unsigned long long printk_clock(void)
>  static void resync_sc_freq(struct sc_data *sc, unsigned int newfreq)
>  {
>  	sc->sync_base = jiffies;
> -	if (!cpu_has_tsc) {
> +	if (!cpu_has_tsc || tsc_disable) {
>  		sc->unstable = 1;
>  		return;
>  	}
> _
>