Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764284AbXJZRoU (ORCPT ); Fri, 26 Oct 2007 13:44:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753102AbXJZRoN (ORCPT ); Fri, 26 Oct 2007 13:44:13 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:37184 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752650AbXJZRoM (ORCPT ); Fri, 26 Oct 2007 13:44:12 -0400 Date: Fri, 26 Oct 2007 19:44:09 +0200 From: Pavel Machek To: Peter Zijlstra Cc: Christoph Lameter , Daniel Phillips , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dkegel@google.com, David Miller , Nick Piggin Subject: Re: [RFC 0/3] Recursive reclaim (on __PF_MEMALLOC) Message-ID: <20071026174409.GA1573@elf.ucw.cz> References: <1189454145.21778.48.camel@twins> <1189457286.21778.68.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1189457286.21778.68.camel@twins> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 34 Hi! > > > or > > > > > > - have a global reserve and selectively serves sockets > > > (what I've been doing) > > > > That is a scalability problem on large systems! Global means global > > serialization, cacheline bouncing and possibly livelocks. If we get into > > this global shortage then all cpus may end up taking the same locks > > cycling thought the same allocation paths. > > Dude, breathe, these boxens of yours will never swap over network simply > because you never configure swap. > > And, _no_, it does not necessarily mean global serialisation. By simply > saying there must be N pages available I say nothing about on which node > they should be available, and the way the watermarks work they will be > evenly distributed over the appropriate zones. Agreed. Scalability of emergency swapping reserved is simply unimportant. Please, lets get swapping to _work_ first, then we can make it faster. No, I do not think we'll ever see a livelock on this. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - 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/