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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Robin H. Johnson" <robbat2@gentoo.org>,
	linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>
Subject: Re: Idle loadavg of ~1, maybe MD related
Date: Sun, 06 Jan 2008 14:53:12 +1100	[thread overview]
Message-ID: <1199591592.7291.69.camel@pasglop> (raw)
In-Reply-To: <20080105190506.38dcf45e.akpm@linux-foundation.org>


> Maybe, but we can usually work around it pretty comfortably.
> 
> If smu_set_fan() is only ever called by a kernel thread then we can simply
> flip it over to using wait_for_completion_interruptible().

Hrm... as of today, it's mostly called from a kernel thread but I don't
totally iron out the possibility that we add control to those things via
sysfs... But that's definitely an option for now.

However, that's only part of the problem. There's a lot of I2C accesses
(and other SMU accesses to read SMU based sensors) and I doubt we can
make all of that "magically" interruptible.

I would much prefer if we had a way to tag a kernel thread to not add to
the load average when in interruptible sleep :-)

> If smu_set_fan() is also called from user processes then things aren't so
> easy...

Ben.



  reply	other threads:[~2008-01-06  3:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-30 10:06 Idle loadavg of ~1, maybe MD related Robin H. Johnson
2008-01-05  9:30 ` Andrew Morton
2008-01-05 10:04   ` Robin H. Johnson
2008-01-05 10:18     ` Benjamin Herrenschmidt
2008-01-06  3:05       ` Andrew Morton
2008-01-06  3:53         ` Benjamin Herrenschmidt [this message]
2008-01-06 11:21         ` Paul Mackerras
2008-01-06 11:29           ` Robin H. Johnson

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