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Date: Thu, 13 May 2010 21:08:14 +0100
From: Matthew Garrett <mjg@redhat.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Alan Stern <stern@rowland.harvard.edu>, Paul Walmsley <paul@pwsan.com>,
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Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 6)
Message-ID: <20100513200814.GA20254@srcf.ucam.org>
References: <alpine.DEB.2.00.1005122118530.7624@utopia.booyaka.com> <Pine.LNX.4.44L0.1005131002380.1695-100000@iolanthe.rowland.org> <20100513191717.GA3428@atomide.com> <20100513192522.GA19256@srcf.ucam.org> <20100513194205.GC3428@atomide.com> <20100513195349.GB19722@srcf.ucam.org> <20100513200003.GE3428@atomide.com>
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On Thu, May 13, 2010 at 01:00:04PM -0700, Tony Lindgren wrote:

> The system stays running because there's something to do. The system
> won't suspend until all the processors hit the kernel idle loop and
> the next_timer_interrupt_critical() returns nothing.

At which point an application in a busy loop cripples you. I think we 
could implement your suggestion more easily by just giving untrusted 
applications an effectively infinite amount of timer slack, but it still 
doesn't handle the case where an app behaves excrutiatingly badly.

-- 
Matthew Garrett | mjg59@srcf.ucam.org