From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id DA7C56B004D for ; Sat, 10 Oct 2009 08:06:45 -0400 (EDT) Date: Sat, 10 Oct 2009 14:06:14 +0200 From: Pavel Machek Subject: Re: [PATCH 00/31] Swap over NFS -v20 Message-ID: <20091010120614.GC1811@ucw.cz> References: <1254405858-15651-1-git-send-email-sjayaraman@suse.de> <20091001174201.GA30068@infradead.org> <1254692482.21044.15.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1254692482.21044.15.camel@laptop> Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: Christoph Hellwig , Suresh Jayaraman , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, Neil Brown , Miklos Szeredi , Wouter Verhelst , trond.myklebust@fys.uio.no List-ID: Hi! > > One of them > > would be the whole VM/net work to just make swap over nbd/iscsi safe. > > Getting those two 'fixed' is going to be tons of interesting work > because they involve interaction with userspace daemons. > > NBD has fairly simple userspace, but iSCSI has a rather large userspace > footprint and a rather complicated user/kernel interaction which will be > mighty interesting to get allocation safe. > > Ideally the swap-over-$foo bits have no userspace component. > > That said, Wouter is the NBD userspace maintainer and has expressed > interest into looking at making that work, but its sure going to be > non-trivial, esp. since exposing PF_MEMALLOC to userspace is a, not over > my dead-bodym like thing. Well, as long as nbd-server is on separate machine (with real swap), safe swapping over network should be ok, without PF_MEMALLOC for userspace or similar nightmares, right? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org