From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Date: Thu, 27 May 2010 18:07:40 +0100 Message-ID: <20100527170740.GA1980@srcf.ucam.org> References: <20100526142430.327ccbc4@schatten.dmk.lab> <20100526141612.3e2e0443@lxorguk.ukuu.org.uk> <20100527003943.07c17f85@lxorguk.ukuu.org.uk> <20100527140655.GA28048@srcf.ucam.org> <20100527155201.GA31937@srcf.ucam.org> <20100527171615.15a1fd3d@lxorguk.ukuu.org.uk> <20100527161943.GA32764@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Thomas Gleixner Cc: Alan Cox , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Florian Mickler , Vitaly Wool , Peter Zijlstra , LKML , Paul@smtp1.linux-foundation.org, felipe.balbi@nokia.com, Linux OMAP Mailing List , Linux PM List-Id: linux-omap@vger.kernel.org On Thu, May 27, 2010 at 07:04:38PM +0200, Thomas Gleixner wrote: > On Thu, 27 May 2010, Matthew Garrett wrote: > > Sure, if you're not using opportunistic suspend then I don't think > > there's any real need for the userspace side of this. The question is > > how to implement something with the useful properties of opportunistic > > suspend without without implementing something pretty much equivalent to > > the userspace suspend blockers. I've sent another mail expressing why I > > don't think your proposed QoS style behaviour provides that. > > Opportunistic suspend is just a deep idle state, nothing else. No. The useful property of opportunistic suspend is that nothing gets scheduled. That's fundamentally different to a deep idle state. > Stop thinking about suspend as a special mechanism. It's not - except > for s2disk, which is an entirely different beast. On PCs, suspend has more in common with s2disk than it does C states. -- Matthew Garrett | mjg59@srcf.ucam.org