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Date: Fri, 7 May 2010 22:39:17 +0100
From: Matthew Garrett <mjg@redhat.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Daniel Walker <dwalker@fifo99.com>, Brian Swetland <swetland@google.com>,
       Alan Stern <stern@rowland.harvard.edu>,
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Subject: Re: [linux-pm] [PATCH 1/8] PM: Add suspend block api.
Message-ID: <20100507213917.GE28906@srcf.ucam.org>
References: <20100507184333.GL387@atomide.com> <20100507184621.GA25978@srcf.ucam.org> <1273259186.3542.93.camel@c-dwalke-linux.qualcomm.com> <20100507192837.GM387@atomide.com> <20100507193353.GA27175@srcf.ucam.org> <20100507195548.GN387@atomide.com> <20100507202859.GA27328@srcf.ucam.org> <20100507205329.GP387@atomide.com> <20100507210304.GA28701@srcf.ucam.org> <20100507212556.GQ387@atomide.com>
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On Fri, May 07, 2010 at 02:25:56PM -0700, Tony Lindgren wrote:
> * Matthew Garrett <mjg@redhat.com> [100507 13:58]:
> > Here's a different example. A process is waiting for a keypress, but 
> > because it's badly written it's also drawing to the screen at 60 frames 
> > per second and preventing the system from every going to idle. How do 
> > you quiesce the system while still ensuring that the keypress will be 
> > delivered to the application?
> 
> I guess it depends. If it's a game and I'm waiting to hit the fire
> button, then I don't want the system to suspend!
> 
> It's starting to sound like you're really using suspend blocks
> to "certify" that the app is safe to keep running.
> 
> Maybe it could be done with some kind of process flag instead that
> would tell "this process is safe to keep running from timer point of view"
> and if that flag is not set, then assume it's OK to stop the process
> at any point?

How do you know to wake the process up in response to the keypress?

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