From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: suspend.c vs driver-model.txt Date: Mon, 29 Jul 2002 19:56:50 +0200 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20020729175650.GA1233@elf.ucw.cz> References: <20020729090041.GB115@elf.ucw.cz> <20020729150807.3604@192.168.4.1> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20020729150807.3604-Q0ErXNX1RuY/GWcAdfcqrQ@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Benjamin Herrenschmidt Cc: Patrick Mochel , Lyle , acpi-devel-pyega4qmqnRoyOMFzWx49A@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > >> The nice thing here, I beleive, is that suspend to disk could then just > >> be an additional generic step between 1) and 2) that takes care of > >> dumping memory content to disk. > > > >It can not, because after saving state you can not easily write to > >swap partition. > > Well, you have to. I mean, you can't write to swap before saving state > (or you'll miss some state information). Which means the device dealing > with the save has to be treated as a special case. At least, that's what > we figured out when discussing this during OLS. Discussing with who? Its rather simple: free half of memory, stop everything, save device state, copy used memory into free memory, continue devices, save data from "free" memory into swap. > >Too complicated. Look at swsusp -- it is designed not to need > >pre-allocated pages, pre-mapped DMA etc. > > I didn't look at it recently, but does it work properly in a solid > way whatever state other devices are ? It is designed to be safe, yes. Pavel -- Worst form of spam? Adding advertisment signatures ala sourceforge.net. What goes next? Inserting advertisment *into* email? ------------------------------------------------------- This sf.net email is sponsored by: Dice - The leading online job board for high-tech professionals. Search and apply for tech jobs today! http://seeker.dice.com/seeker.epl?rel_code=31