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From: Chris Snook <csnook@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Hansen <x@jeffhansen.com>,
	torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
	mingo@elte.hu
Subject: Re: [PATCH] Re: x86_32 tsc/pit and hrtimers
Date: Thu, 09 Oct 2008 14:39:00 -0400	[thread overview]
Message-ID: <48EE4FC4.7070902@redhat.com> (raw)
In-Reply-To: <alpine.LFD.2.00.0810090910510.3237@apollo>

Thomas Gleixner wrote:
> On Wed, 8 Oct 2008, Jeff Hansen wrote:
> 
>> [HRTIMER]: Add highres=noverify option to bypass clocksource verification
>>
>> This disregards the CLOCK_SOURCE_MUST_VERIFY flag on all clocksources.
>> This is particularly useful on legacy x86_32 systems that have no ACPI,
>> LAPIC, or HPET timers, where only TSC and PIT are available.
> 
> While I agree in principle, adding this to highres is the wrong thing
> to do. This is a property of clocksources and not of high resolution
> timer support.
> 
> The affected clocksource is TSC and it should go there as a command
> line option e.g. tsc=stable, which in turn clears the
> CLOCK_SOURCE_MUST_VERIFY flag in the tsc clocksource.
> 
> Thanks,
> 
> 	tglx

Fair enough, but do you think it's worthwhile to have an option to 
disable CLOCK_SOURCE_MUST_VERIFY checking for all timers, or should we 
implement this on a case-by-case basis when there's legitimate cause, 
like with TSC?

-- Chris

  reply	other threads:[~2008-10-09 18:40 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-07 22:41 x86_32 tsc/pit and hrtimers Jeff Hansen
2008-10-08 18:41 ` Chris Snook
2008-10-08 19:46   ` Jeff Hansen
2008-10-08 20:25     ` Chris Snook
2008-10-08 21:43       ` [PATCH] " Jeff Hansen
2008-10-08 21:47         ` Randy.Dunlap
2008-10-08 21:47         ` Chris Snook
2008-10-08 21:56           ` Jeff Hansen
2008-10-09  7:14             ` Thomas Gleixner
2008-10-09 18:39               ` Chris Snook [this message]
2008-10-09 19:18                 ` Thomas Gleixner
2008-10-09 19:45                   ` Jeff Hansen
2008-10-09 19:53                     ` Thomas Gleixner
2008-10-09 20:45                       ` Alok kataria
2008-10-09 21:03                         ` Chris Snook
2008-10-09 21:18                           ` Jeff Hansen
2008-10-09 22:03                             ` Alok Kataria
2008-10-09 21:53                           ` Alok Kataria
2008-10-09 22:50                             ` Chris Snook
2008-10-09 23:22                               ` Alok Kataria
2008-10-09 23:37                                 ` Chris Snook
2008-10-10 14:24                                   ` Jeff Hansen
2008-10-09 17:20   ` Pavel Machek

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