Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755907Ab2BHP0u (ORCPT ); Wed, 8 Feb 2012 10:26:50 -0500 Received: from cantor2.suse.de ([195.135.220.15]:39908 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754553Ab2BHP0t (ORCPT ); Wed, 8 Feb 2012 10:26:49 -0500 Date: Wed, 8 Feb 2012 15:26:46 +0000 From: Mel Gorman To: Hillf Danton Cc: Andrew Morton , Linux-MM , Linux-Netdev , LKML , David Miller , Neil Brown , Peter Zijlstra Subject: Re: [PATCH 00/15] Swap-over-NBD without deadlocking V8 Message-ID: <20120208152645.GK5938@suse.de> References: <1328568978-17553-1-git-send-email-mgorman@suse.de> <20120207132745.GH5938@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1397 Lines: 34 On Wed, Feb 08, 2012 at 08:51:11PM +0800, Hillf Danton wrote: > On Tue, Feb 7, 2012 at 9:27 PM, Mel Gorman wrote: > > On Tue, Feb 07, 2012 at 08:45:18PM +0800, Hillf Danton wrote: > >> If it is feasible to bypass hang by tuning min_mem_kbytes, > > > > No. Increasing or descreasing min_free_kbytes changes the timing but it > > will still hang. > > > >> things may > >> become simpler if NICs are also tagged. > > > > That would mean making changes to every driver and they do not necessarily > > know what higher level protocol like TCP they are transmitting. How is > > that simpler? What is the benefit? > > > The benefit is to avoid allocating sock buffer in softirq by recycling, > then the changes in VM core maybe less. > The VM is responsible for swapping. It's reasonable that the core VM has responsibility for it without trying to shove complexity into drivers or elsewhere unnecessarily. I see some benefit in following on by recycling some skbs and only allocating from softirq if no recycled skbs are available. That potentially improves performance but I do not recycling as a replacement. -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/