From: Christoph Hellwig <hch@infradead.org>
To: Dave Jones <davej@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org
Subject: Re: fishy code in arch/x86/kernel/tsc.c:time_cpufreq_notifier()
Date: Mon, 1 Jun 2009 12:39:14 -0400 [thread overview]
Message-ID: <20090601163914.GA6098@infradead.org> (raw)
In-Reply-To: <20090601162955.GA15237@redhat.com>
On Mon, Jun 01, 2009 at 12:29:55PM -0400, Dave Jones wrote:
> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
> index d57de05..78c54ea 100644
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -631,17 +631,15 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
> void *data)
> {
> struct cpufreq_freqs *freq = data;
> - unsigned long *lpj, dummy;
> + unsigned long *lpj;
>
> if (cpu_has(&cpu_data(freq->cpu), X86_FEATURE_CONSTANT_TSC))
> return 0;
>
> - lpj = &dummy;
> - if (!(freq->flags & CPUFREQ_CONST_LOOPS))
> + lpj = &boot_cpu_data.loops_per_jiffy;
> #ifdef CONFIG_SMP
> + if (!(freq->flags & CPUFREQ_CONST_LOOPS))
> lpj = &cpu_data(freq->cpu).loops_per_jiffy;
> -#else
> - lpj = &boot_cpu_data.loops_per_jiffy;
> #endif
This makes the code look a lot more sane and should fix the potential
issue.
next prev parent reply other threads:[~2009-06-01 16:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-01 14:21 Christoph Hellwig
2009-06-01 16:29 ` Dave Jones
2009-06-01 16:39 ` Christoph Hellwig [this message]
2009-06-01 20:56 ` Jon Masters
2009-06-01 21:49 ` Michael S. Zick
2009-06-01 21:50 ` Michael S. Zick
2009-06-01 22:54 ` Daniel Barkalow
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