From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761016AbXGFJQf (ORCPT ); Fri, 6 Jul 2007 05:16:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762923AbXGFJQU (ORCPT ); Fri, 6 Jul 2007 05:16:20 -0400 Received: from nigel.suspend2.net ([203.171.70.205]:52306 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762895AbXGFJQT (ORCPT ); Fri, 6 Jul 2007 05:16:19 -0400 From: Nigel Cunningham To: Miklos Szeredi Subject: Re: [PATCH] Remove process freezer from suspend to RAM pathway Date: Fri, 6 Jul 2007 19:16:16 +1000 User-Agent: KMail/1.9.6 Cc: oliver@neukum.org, rjw@sisk.pl, nigel@suspend2.net, pavel@ucw.cz, benh@kernel.crashing.org, mjg59@srcf.ucam.org, linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org References: <20070703042916.GA17240@srcf.ucam.org> <200707060951.47555.oliver@neukum.org> In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart8580040.uTIAtyy5Kl"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200707061916.17590.nigel@nigel.suspend2.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --nextPart8580040.uTIAtyy5Kl Content-Type: text/plain; charset="cp 850" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi. On Friday 06 July 2007 19:09:43 Miklos Szeredi wrote: > > > > Moreover, if FUSE implements syncing, then the sync from within the= =20 freezer > > > > will almost certainly deadlock. > > >=20 > > > Rafael, think positively: by the time fuse implements sync(), the > > > freezer will be long gone ;) > >=20 > > Now you are entering really dangerous territory. > > If you can implement a meaningfull sync method, you must have dirty > > pages in the page cache. That means you are in the page freeing path > > of the vm. Then we are in real trouble. Don't even think about it. >=20 > VM induced deadlocks are real nasty. I have thought about them a lot > already. Suspend shouldn't introduce any big surprises. Suspend isn't introducing the surprises. Fuse is. It creates the potential= =20 deadlocks simply by existing (this isn't suspend or hibernate specific). Nigel --nextPart8580040.uTIAtyy5Kl Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBGjghhN0y+n1M3mo0RAqueAJ9O6KMD1i4aV8jCQlPzl/DH0awBZwCg0KFs ByEuy78qc8ls5c0jPjFkEgA= =NZlk -----END PGP SIGNATURE----- --nextPart8580040.uTIAtyy5Kl--