From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from burns.conectiva (burns.conectiva [10.0.0.4]) by perninha.conectiva.com.br (Postfix) with SMTP id B789138CF4 for ; Thu, 9 Aug 2001 17:47:35 -0300 (EST) Date: Thu, 9 Aug 2001 17:47:35 -0300 (BRST) From: Rik van Riel Subject: Re: Swapping for diskless nodes In-Reply-To: <20010809125033.E1200@nightmaster.csn.tu-chemnitz.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Oeser Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Thu, 9 Aug 2001, Ingo Oeser wrote: > Are there any races I have to consider? Well, this IS a big issue against swap over network. Swap over network is inherently prone to deadlock situations, due to the following three problems: 1) we swap pages out when we are close to running out of free memory 2) to write pages out over the network, we need to allocate space to assemble network packets 3) we need to have memory to receive the ACKs on the packets we sent out The only real solution to this would be memory reservations so we know this memory won't be used for other purposes. What we can do right now is be careful about how many writeouts over the network we do at the same time, but that will still get us killed in case of a ping flood ;) regards, Rik -- IA64: a worthy successor to the i860. http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com/ -- 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/