Re: [PATCH RFC] x86, tsc: Allow for high latency in quick_pit_calibrate()

From: Adrian Hunter <adrian.hunter@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>,
	Andy Lutomirski <luto@amacapital.net>,
	LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Len Brown <lenb@kernel.org>, George Spelvin <linux@horizon.com>,
	Ingo Molnar <mingo@kernel.org>,
	a.p.zijlstra@chello.nl, arjan@infradead.org, bp@alien8.de,
	penberg@iki.fi, akpm@linux-foundation.org
Subject: Re: [PATCH RFC] x86, tsc: Allow for high latency in quick_pit_calibrate()
Date: Mon, 06 Jul 2015 09:48:58 +0300	[thread overview]
Message-ID: <559A24DA.7040004@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1506221514150.4107@nanos>

On 22/06/15 16:14, Thomas Gleixner wrote:
> On Mon, 22 Jun 2015, Adrian Hunter wrote:
>> On 03/06/15 19:23, Thomas Gleixner wrote:
>>> On Wed, 3 Jun 2015, Adrian Hunter wrote:
>>>
>>>> On 03/06/15 06:30, Andi Kleen wrote:
>>>>>> Then the changelog should say that I think.  The current text says
>>>>>> "Fast TSC calibration will always fail", which, to me, suggests that
>>>>>> either the slow calibration will work or that the changelog message
>>>>>> should be changed.
>>>>>
>>>>> Ok. No, the slow calibration works I believe.
>>>>
>>>> Yeah, so the (only?) downside is the 50ms wasted on Fast TSC
>>>> calibration.  What about this?
>>>
>>> I'm certainly happy to apply this one. 
>>
>> George Spelvin began investigating improving quick_pit_calibrate() but Ingo
>> anyway suggested this patch as the first, so can this be applied?
> 
> Oh, yes. I simply forgot to pick it up. Thanks for the reminder.

Sorry to bother you, but I don't still don't see the patch anywhere?