From: Michael Witten <mfwitten@gmail.com>
To: Arjan van de Ven <arjanvandeven@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>,
John Stultz <johnstul@us.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>, Len Brown <lenb@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] clocksource: Load the ACPI PM clocksource asynchronously
Date: Wed, 11 Apr 2012 20:04:45 -0000 [thread overview]
Message-ID: <041683e0088341c2b6d78e97f05948eb-mfwitten@gmail.com> (raw)
In-Reply-To: <CADyApD2UZebJd_nSJHAWkjz=PT4_DZfnSr38geqUb1kvJzKi-g@mail.gmail.com>
On Sun, 8 Apr 2012 19:20:22 -0700, Arjan van de Ven wrote:
>> to which I bisected as the culprit for very strange load balance
>> behavior on my machine.
>>
>> With this patch in place, my CPU is constantly being pegged at 100%
>> (and my CPU monitor sometimes registers NaN%), regardless of the
>> active governor and under conditions when my computer would normally
>> be idling quite placidly.
>>
>> Reverting this commit does indeed remove the problem from previously
>> problematic builds.
>>
>>
> any chance of a dmesg? (or even better, a diff of the dmesg from
> abefore and fter)
Doh! I should have thought of that.
The dmesg output for a kernel built from your patch's commit yields
this interesting line:
PM-Timer running at invalid rate: 113% of normal - aborting.
That certainly sounds unsavory!
Here is some other, probably uninteresting context:
--- good-dmesg.txt
+++ bad-dmesg.txt
[...]
Initializing cgroup subsys cpu
-Linux version 3.3.0-rc1-good-12d6d41276def096cb3f7dc36f438db9ed6a0a8d+ [...]
+Linux version 3.3.0-rc1-bad-b519508298e0292e1771eecf14aaf67755adc39d+ [...]
[...]
Fast TSC calibration using PIT
-Detected 798.093 MHz processor.
+Detected 798.071 MHz processor.
-Calibrating delay loop (skipped), value calculated using timer frequency.. 1596.18 BogoMIPS (lpj=798093)
+Calibrating delay loop (skipped), value calculated using timer frequency.. 1596.14 BogoMIPS (lpj=798071)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 512
Initializing cgroup subsys cpuacct
[...]
system 00:0c: Plug and Play ACPI device, IDs PNP0c01 (active)
pnp: PnP ACPI: found 13 devices
ACPI: ACPI bus type pnp unregistered
-Switching to clocksource acpi_pm
[...]
+PM-Timer running at invalid rate: 113% of normal - aborting.
Sincerely,
Michael Witten
P.S.
I'm terribly sorry for the delayed reply; Gmail somehow managed to
throw away this thread entirely (actually, I probably threw it away,
but I'm content to blame my tools; after all, they can't deny it!).
next prev parent reply other threads:[~2012-04-11 20:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-31 4:51 [PATCH] clocksource: Load the ACPI PM clocksource asynchronously Arjan van de Ven
2012-02-02 2:40 ` john stultz
2012-04-08 5:58 ` Michael Witten
[not found] ` <CADyApD2UZebJd_nSJHAWkjz=PT4_DZfnSr38geqUb1kvJzKi-g@mail.gmail.com>
2012-04-11 20:04 ` Michael Witten [this message]
2012-04-11 21:13 ` Thomas Gleixner
2012-04-11 22:15 ` [tip:timers/urgent] Revert "clocksource: Load the ACPI PM clocksource asynchronously" tip-bot for Thomas Gleixner
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