From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 6 Aug 2007 14:38:42 -0500 From: Matt Mackall Subject: Re: [PATCH 03/10] mm: tag reseve pages Message-ID: <20070806193842.GB11115@waste.org> References: <20070806102922.907530000@chello.nl> <20070806103658.356795000@chello.nl> <1186426079.11797.88.camel@lappy> <20070806185926.GB22499@one.firstfloor.org> <20070806121053.baed9691.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070806121053.baed9691.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Andi Kleen , Peter Zijlstra , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Miller , Daniel Phillips , Pekka Enberg , Lee Schermerhorn , Steve Dickson List-ID: On Mon, Aug 06, 2007 at 12:10:53PM -0700, Andrew Morton wrote: > On Mon, 6 Aug 2007 20:59:26 +0200 Andi Kleen wrote: > > > > precious page flag > > > > I always cringe when I hear that. It's really more than node/sparsemem > > use too many bits. If we get rid of 32bit NUMA that problem would be > > gone for the node at least because it could be moved into the mostly > > unused upper 32bit part on 64bit architectures. > > Removing 32-bit NUMA is attractive - NUMAQ we can probably live without, > not sure about summit. But superh is starting to use NUMA now, due to > varying access times of various sorts of memory, and one can envisage other > embedded setups doing that. > > Plus I don't think there are many flags left in the upper 32-bits. ia64 > swooped in and gobbled lots of them, although it's not immediately clear > how many were consumed. > > > The alternative would be to investigate again what it does to the > > kernel to just use different lookup methods for this. > > That's cringeworthy too, I expect. Perhaps the node info could be pulled out into a parallel and effectively read-only array of shorts. -- Mathematics is the supreme nostalgia of our time. -- 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