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Date: Thu, 13 May 2010 20:53:49 +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>,
       Arve =?iso-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
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Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 6)
Message-ID: <20100513195349.GB19722@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>
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On Thu, May 13, 2010 at 12:42:05PM -0700, Tony Lindgren wrote:

> 1. In the kernel, we add one more timer queue for critical timers.
>    The current timer queue(s) stay as it is.
> 
> 2. We allow selecting the timer based on some flag, the default
>    behaviour being the current default timer queue.
> 
> 3. Then we add next_timer_interupt_critical() to only query the
>    critical timers along the lines of the current next_timer_interrupt().
> 
> 4. We implement a custom pm_idle that suspends the system based on
>    some logic and checking if next_timer_interrupt_critical() is
>    empty. If the next_timer_interrupt_critical() does not return
>    anything, we assume it's OK to suspend the system.

Ok. So we stick the untrusted bits of userspace on the critical timer 
list. Now we get a network packet that generates a wakeup event and gets 
read by an application. What happens if that application can't fully 
process the packet in a single timeslice?

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