From: Dan Magenheimer <dan.magenheimer@oracle.com>
To: john stultz <johnstul@us.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Brian Bloniarz <bmb@athenacr.com>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andi Kleen <andi@firstfloor.org>,
Arjan van de Ven <arjan@infradead.org>,
Venkatesh Pallipadi <venki@google.com>,
chris.mason@oracle.com, linux-kernel@vger.kernel.org
Subject: RE: [PATCH] x86: Export tsc related information in sysfs
Date: Mon, 24 May 2010 17:01:06 -0700 (PDT) [thread overview]
Message-ID: <bcb35f6d-e632-4fb6-bef0-8c55335ef537@default> (raw)
In-Reply-To: <1274743836.2954.104.camel@localhost.localdomain>
> Sorry, this is sort of mixing points
> Again, this is mixing the discussion.
Oops, sorry, missed that. :-}
> Maybe something like a tsc_long_calibration=1 option would allow for
> this?
Sounds good to me. If it's non-obvious what value to choose for
the new calibration, maybe specifying it in MS (per MAX_QUICK_PIT_MS
in arch/x86/kernel/tsc.c) would be nice.
> However, I really do like the idea of pulling the stamped value from
> the MSR and if its close to what we quickly calibrated, use that.
On a quick sample of two machines looking at the TSC calibration
done by Xen (which exposes the equivalent of tsc_khz), it appears
that the stamped value is different from the calibration by about
1000ppm. YMMV.
next prev parent reply other threads:[~2010-05-25 0:02 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-20 19:19 [PATCH] x86: Export tsc related information in sysfs Brian Bloniarz
2010-05-22 2:03 ` john stultz
2010-05-22 3:33 ` H. Peter Anvin
2010-05-24 18:13 ` Dan Magenheimer
2010-05-24 18:19 ` H. Peter Anvin
2010-05-24 18:51 ` john stultz
2010-05-24 20:20 ` H. Peter Anvin
2010-05-24 20:39 ` john stultz
2010-05-24 21:26 ` H. Peter Anvin
2010-05-24 22:04 ` Dan Magenheimer
2010-05-24 22:30 ` H. Peter Anvin
2010-05-24 22:49 ` john stultz
2010-05-24 23:16 ` Dan Magenheimer
2010-05-24 23:19 ` H. Peter Anvin
2010-05-24 23:30 ` john stultz
2010-05-24 23:42 ` Andi Kleen
2010-05-25 0:01 ` Dan Magenheimer [this message]
2010-05-25 0:07 ` H. Peter Anvin
2010-05-25 1:33 ` Brian Bloniarz
2010-05-26 0:16 ` Brian Bloniarz
2010-05-26 0:48 ` john stultz
2010-05-26 2:50 ` Brian Bloniarz
2010-05-26 12:35 ` Thomas Gleixner
2010-05-26 14:26 ` Dan Magenheimer
2010-05-26 14:41 ` Thomas Gleixner
2010-05-26 15:04 ` john stultz
2010-05-26 16:02 ` Brian Bloniarz
2010-05-26 16:25 ` john stultz
2010-05-26 18:24 ` H. Peter Anvin
2010-05-26 18:44 ` Brian Bloniarz
2010-05-26 18:51 ` H. Peter Anvin
2010-05-26 20:19 ` john stultz
2010-05-26 21:06 ` H. Peter Anvin
2010-05-26 19:49 ` john stultz
2010-05-26 20:22 ` Brian Bloniarz
2010-05-26 12:30 ` Thomas Gleixner
-- strict thread matches above, loose matches on Subject: below --
2010-05-15 1:40 Venkatesh Pallipadi
2010-05-15 9:57 ` Andi Kleen
2010-05-15 13:29 ` Dan Magenheimer
2010-05-15 16:48 ` Venkatesh Pallipadi
2010-05-15 19:14 ` Arjan van de Ven
2010-05-15 22:32 ` Dan Magenheimer
2010-05-16 5:43 ` Arjan van de Ven
2010-05-16 9:20 ` Thomas Gleixner
2010-05-16 16:42 ` Dan Magenheimer
2010-05-16 19:14 ` Thomas Gleixner
2010-05-17 1:31 ` Dan Magenheimer
2010-05-17 5:06 ` Arjan van de Ven
2010-05-18 9:58 ` Peter Zijlstra
2010-05-18 10:03 ` Peter Zijlstra
2010-05-18 11:25 ` Andi Kleen
2010-05-18 11:58 ` Peter Zijlstra
2010-05-18 15:13 ` Dan Magenheimer
2010-05-18 16:40 ` H. Peter Anvin
2010-05-18 16:52 ` Peter Zijlstra
2010-05-18 17:04 ` H. Peter Anvin
2010-05-18 17:49 ` Dan Magenheimer
2010-05-18 18:46 ` H. Peter Anvin
2010-05-18 19:00 ` Dan Magenheimer
2010-05-18 19:16 ` Dan Magenheimer
2010-05-18 19:26 ` H. Peter Anvin
2010-05-18 20:29 ` Dan Magenheimer
2010-05-18 20:34 ` H. Peter Anvin
2010-05-18 21:02 ` Dan Magenheimer
2010-05-18 21:13 ` Andi Kleen
2010-05-19 6:26 ` Peter Zijlstra
2010-05-17 10:20 ` Thomas Gleixner
2010-05-16 20:29 ` Arjan van de Ven
2010-05-17 10:26 ` Andi Kleen
2010-06-04 14:24 ` Pavel Machek
2010-05-15 22:45 ` Thomas Gleixner
2010-05-17 10:22 ` Andi Kleen
2010-05-17 15:23 ` Dan Magenheimer
2010-05-17 16:56 ` Andi Kleen
2010-05-17 22:36 ` Thomas Gleixner
2010-05-17 23:33 ` Dan Magenheimer
2010-05-18 0:00 ` Ingo Molnar
2010-05-18 0:02 ` Ingo Molnar
2010-05-15 12:35 ` Jaswinder Singh Rajput
2010-05-15 14:37 ` Venkatesh Pallipadi
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