From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 23 Apr 2003 23:36:52 -0400 From: Benjamin LaHaise Subject: Re: 2.5.68-mm2 Message-ID: <20030423233652.C9036@redhat.com> References: <20030423012046.0535e4fd.akpm@digeo.com> <18400000.1051109459@[10.10.2.4]> <20030423144648.5ce68d11.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030423144648.5ce68d11.akpm@digeo.com>; from akpm@digeo.com on Wed, Apr 23, 2003 at 02:46:48PM -0700 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: "Martin J. Bligh" , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, Apr 23, 2003 at 02:46:48PM -0700, Andrew Morton wrote: > Ingo-rmap seems a better solution to me. It would be a fairly large change > though - we'd have to hold the four atomic kmaps across an entire pte page > in copy_page_range(), for example. But it will then have good locality of > reference between adjacent pages and may well be quicker than pte_chains. Actually, Ingo's rmap style sounds very similar to what I first implemented in one of my stabs at rmap. It has a nasty side effect of being worst case for cache organisation -- the sister page tends to map to the exact same cache line in some processors. Whoops. That said, I think that the rmap pte-chains can really stand a bit of optimization by means of discarding a couple of bits, as well as merging for adjacent pages, so I don't think the overhead is a lost cause yet. And nobody has written the clone() patch for bash yet... -ben -- Junk email? aart@kvack.org -- 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: aart@kvack.org