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From: Matthias Urlichs <smurf@smurf.noris.de>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, johnstul@us.ibm.com,
	torvalds@osdl.org, bunk@stusta.de, lethal@linux-sh.org,
	hirofumi@mail.parknet.co.jp
Subject: Re: REGRESSION: the new i386 timer code fails to sync CPUs
Date: Sun, 23 Jul 2006 10:16:04 +0200	[thread overview]
Message-ID: <20060723081604.GD27566@kiste.smurf.noris.de> (raw)
In-Reply-To: <20060722173649.952f909f.akpm@osdl.org>

Hi,

Azndrew Morton:
> What is 2.6.17-test-1.29?

My test build; standard kernel during bisection.

> How do you know that 5d0cf410e94b1f1ff852c3f210d22cc6c5a27ffa caused this?
> 
git bisect.

> Are you able to test the below?  It should fix up the reporting.
> 
Applied.

> Are you able to compare the present bootlog with the 2.6.17 bootlog?
> 
Sure. The diff says:

 checking TSC synchronization across 4 CPUs:
+CPU#0 had 748437 usecs TSC skew, fixed it up.
+CPU#1 had 748437 usecs TSC skew, fixed it up.
+CPU#2 had -748437 usecs TSC skew, fixed it up.
+CPU#3 had -748437 usecs TSC skew, fixed it up.
 Brought up 4 CPUs
-migration_cost=4000,8000
+migration_cost=85,1724

... but apparently, that skew is not corrected.

These numbers do match the difference in observed "date" outputs.

-- 
Matthias Urlichs   |   {M:U} IT Design @ m-u-it.de   |  smurf@smurf.noris.de
Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de
 - -
The first place you look for something
is the last place you'd expect to find it.

  reply	other threads:[~2006-07-23  8:17 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-07-22 23:36 REGRESSION: the new i386 timer code fails to sync CPUs Matthias Urlichs
2006-07-23  0:36 ` Andrew Morton
2006-07-23  8:16   ` Matthias Urlichs [this message]
2006-07-23 11:46     ` Andrew Morton
2006-07-23 12:08       ` Matthias Urlichs
2006-07-23 12:37         ` Andrew Morton
2006-07-23 12:58           ` Matthias Urlichs
2006-07-24 15:52           ` Siddha, Suresh B
2006-07-24 15:58           ` john stultz
2006-07-24 17:17             ` Matthias Urlichs
2006-07-24 17:51               ` Andi Kleen
2006-07-24 20:54                 ` john stultz
2006-07-30  9:03                   ` Andrew Morton
2006-07-30  9:49                     ` Matthias Urlichs
2006-07-30 20:10                     ` Andi Kleen
2006-07-30 20:55                       ` Andrew Morton
2006-07-30 21:13                       ` Matthias Urlichs
2006-07-30 21:20                         ` Arjan van de Ven
2006-07-30 21:55                           ` Matthias Urlichs
2006-08-01  1:47                             ` Siddha, Suresh B
2006-08-01  3:14                               ` Matthias Urlichs
2006-07-30 21:57                         ` Andi Kleen
2006-07-30 22:28                           ` Matthias Urlichs
2006-07-31 14:24                     ` Matthias Urlichs
2006-07-24 17:39             ` Andi Kleen

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