From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933822AbXDZJ3R (ORCPT ); Thu, 26 Apr 2007 05:29:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933795AbXDZJ3E (ORCPT ); Thu, 26 Apr 2007 05:29:04 -0400 Received: from nigel.suspend2.net ([203.171.70.205]:49561 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933805AbXDZJ2o (ORCPT ); Thu, 26 Apr 2007 05:28:44 -0400 Subject: Re: Back to the future. From: Nigel Cunningham Reply-To: nigel@nigel.suspend2.net To: Pekka Enberg Cc: Linus Torvalds , LKML In-Reply-To: <84144f020704260117l3794ebe3q7aaa49bc98888d01@mail.gmail.com> References: <1177567481.5025.211.camel@nigel.suspend2.net> <84144f020704260028q190fc90fs8f9ea703e42e7910@mail.gmail.com> <1177573348.5025.224.camel@nigel.suspend2.net> <84144f020704260117l3794ebe3q7aaa49bc98888d01@mail.gmail.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-uGDdeN97br9L6RTIi/gk" Date: Thu, 26 Apr 2007 19:28:43 +1000 Message-Id: <1177579723.5025.233.camel@nigel.suspend2.net> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-uGDdeN97br9L6RTIi/gk Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi. On Thu, 2007-04-26 at 11:17 +0300, Pekka Enberg wrote: > Hi Nigel, >=20 > On 4/26/07, Nigel Cunningham wrote: > > * Doing things in the right order? (Prepare the image, then do the > > atomic copy, then save). >=20 > As I am a total newbie to the power management code, I am unable to > spot the conceptual difference in uswsusp suspend.c:suspend_system() > and suspend2 kernel/power/suspend.c:suspend_main(). How are they > different? Will discuss in irc since you've appeared there... > On 4/26/07, Nigel Cunningham wrote: > > * Mulithreaded I/O (might as well use multiple cores to compress the > > image, now that we're hotplugging later). >=20 > I assume this doesn't affect the kernel at all with uswsusp? Well uswsusp would benefit from using multiple threads - if it can - to do the work. I saw quite an improvement from implementing it. > On 4/26/07, Nigel Cunningham wrote: > > * Modular design? >=20 > This is too broad. Please be more specific of the problems the current > suspend and snapshot/shutdown code in the kernel has. Did you see the 'Reasons to merge' email I sent? It has more detail on this. > Now to add to your list, as far as I can tell, suspend2 provides > better feedback to the user via the netlink mechanism (although the > kernel shouldn't be sending messages such as userui_redraw but instead > let the userspace know of the actual events, for example, that tasks > have now been frozen). However, I am unsure if this is still relevant > as most of the work (snapshot writing) is being done in userspace > where we explicitly know when processes have been frozen, when the > snapshot is finished, and when it's written to disk. =46rom uswsusp's point of view, yeah. But I'm still coming from the 'doing this in kernelspace makes far more sense' perspective. Regards, Nigel --=-uGDdeN97br9L6RTIi/gk Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBGMHDLN0y+n1M3mo0RAsTCAKCA1+Z8WvUiysKBhMbXNJ84LyiNuACfV9dC jNUcIOk6KskX1JJk30palKI= =skmm -----END PGP SIGNATURE----- --=-uGDdeN97br9L6RTIi/gk--