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From: Ingo Molnar <mingo@elte.hu>
To: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: H Peter Anvin <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: Support always running TSC on Intel CPUs
Date: Tue, 18 Nov 2008 09:09:52 +0100	[thread overview]
Message-ID: <20081118080952.GE17838@elte.hu> (raw)
In-Reply-To: <20081118001137.GA12350@linux-os.sc.intel.com>


* Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:

> +	if (c->x86_power & (1 << 8)) {
>  		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
> +		set_cpu_cap(c, X86_FEATURE_NOSTOP_TSC);
> +	}

hm, the naming is a bit confusing. We now have 3 variants:

  X86_FEATURE_TSC
  X86_FEATURE_CONSTANT_TSC
  X86_FEATURE_NOSTOP_TSC

NOSTOP_TSC is basically what CONSTANT_TSC should have been to begin 
with ;-)

i'd suggest to rename it to this:

  X86_FEATURE_TSC
  X86_FEATURE_CONSTANT_FREQ_TSC
  X86_FEATURE_STABLE_TSC

... with CONSTANT_FREQ_TSC not having any real role in the long run. 
(it's similarly problematic to a completely unstable TSC)

does this sound ok?

	Ingo

  parent reply	other threads:[~2008-11-18  8:10 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-18  0:11 [PATCH] x86: Support always running TSC on Intel CPUs Venki Pallipadi
2008-11-18  0:13 ` H. Peter Anvin
2008-11-18  0:16   ` Pallipadi, Venkatesh
2008-11-18  0:18     ` H. Peter Anvin
2008-11-18  0:49       ` Venki Pallipadi
2008-11-18  0:52         ` H. Peter Anvin
2008-11-18  1:05           ` Venki Pallipadi
2008-11-18  1:07             ` H. Peter Anvin
2008-11-18  3:26               ` Arjan van de Ven
2008-11-18  3:27                 ` H. Peter Anvin
2008-11-18  8:09 ` Ingo Molnar [this message]
2008-11-18 14:55   ` Joe Korty
2008-11-18 16:05     ` Ingo Molnar
2008-11-18 16:47       ` Pallipadi, Venkatesh
2008-11-18 16:54         ` Joe Korty
2008-11-18 17:01         ` H. Peter Anvin
2008-11-18 16:48       ` Joe Korty

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