From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 24 Jul 2002 19:45:35 -0700 From: William Lee Irwin III Subject: Re: page_add/remove_rmap costs Message-ID: <20020725024535.GB2907@holomorphy.com> References: <3D3E4A30.8A108B45@zip.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Description: brief message Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Andrew Morton , "linux-mm@kvack.org" List-ID: On Tue, 23 Jul 2002, Andrew Morton wrote: >> Then again, if the per-vma pfn->pte lookup is feasible, we may not need >> the pte_chain at all... On Wed, Jul 24, 2002 at 01:24:13PM -0300, Rik van Riel wrote: > It is feasible, both davem and bcrl made code to this effect. The > only problem with that code is that it gets ugly quick after mremap. I actually took an axe to mremap recently, and althought the pieces never came back together into working code, it's clear that it's far from optimal. It's doing a virtual sweep over the region and repeating the pgd -> pmd -> pte traversals for each pte. So invading that territory may well be justifiable on more grounds than rmap itself. I may revisit mremap.c at some point in the distant future if that tweaking alone is considered valuable. Cheers, Bill -- 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/