From: Chris Snook <csnook@redhat.com>
To: Jan Engelhardt <jengelh@computergmbh.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Few interrupts with NO_HZ
Date: Mon, 06 Aug 2007 09:47:52 -0400 [thread overview]
Message-ID: <46B72688.8070303@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0708061247150.13469@fbirervta.pbzchgretzou.qr>
Jan Engelhardt wrote:
> Hi,
>
>
> this more of an informational question. So:
>
> kernel version is 2.6.22.1 on i686
>
> /proc/uptime
> 9917.81 9140.90 (2h45m)
>
> /proc/cpuinfo:
> CPU0
> 0: 282 IO-APIC-edge timer
>
> this is kinda neat, I expected much more interrupts than just 282 since
> boot. What kernel code actually uses the irq0 timer?
If you don't have an HPET (and most single-processor systems do not) the kernel
is probably using the PIT to wake the processor from low-power sleep states,
since the LAPIC timer is disabled in these states. If your box is mostly idle,
you might want to use powertop to figure out why it's entering low power states
so infrequently.
-- Chris
next prev parent reply other threads:[~2007-08-06 13:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-06 10:52 Few interrupts with NO_HZ Jan Engelhardt
2007-08-06 13:47 ` Chris Snook [this message]
2007-08-06 14:28 ` Jan Engelhardt
2007-08-06 14:35 ` Chris Snook
2007-08-06 22:31 ` Kyle McMartin
[not found] <fa.09fMUH3GW8WqIBDx7yLbNn+7hAo@ifi.uio.no>
2007-08-06 23:22 ` Robert Hancock
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