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From: Robert Love <rml@tech9.net>
To: Roger Larsson <roger.larsson@skelleftea.mail.telia.com>
Cc: Christian Vogel <vogel@skunk.physik.uni-erlangen.de>,
	linux-kernel@vger.kernel.org
Subject: Re: linux-2.6.0-test2: Never using pm_idle (CPU wasting power)
Date: 31 Jul 2003 15:58:57 -0700	[thread overview]
Message-ID: <1059692337.931.325.camel@localhost> (raw)
In-Reply-To: <200308010045.08178.roger.larsson@skelleftea.mail.telia.com>

On Thu, 2003-07-31 at 15:45, Roger Larsson wrote:

> This smells preemptive kernel, correct?

Doesn't look like anything specific to kernel preemption to me.

But if need_resched() is never zero, the while loop fails, and
schedule() _should_ be reached. So something is fishy here. Looking at
it the other way, however, if schedule() is never called, then
need_resched() will remain non-zero forever. Maybe you mean
need_resched() is never non-zero, i.e., it is always zero?

I think the problem is that there is a race between whatever you are
saying ACPI is doing with pm_idle and the setting of idle. Actually,
that is exactly what you are saying :)

Your fix smells exactly of that. Maybe have APCI set need_resched, so
the loop flips over again?

	Robert Love



  reply	other threads:[~2003-07-31 22:52 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-31 13:07 linux-2.6.0-test2: Never using pm_idle (CPU wasting power) Christian Vogel
2003-07-31 14:12 ` Charles Lepple
2003-07-31 14:44   ` Christian Vogel
2003-07-31 22:45 ` Roger Larsson
2003-07-31 22:58   ` Robert Love [this message]
2003-07-31 23:26     ` Robert Love
2003-07-31 22:59 ` Andrew Morton
2003-08-01  9:18   ` Christian Vogel

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