From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 7 May 2002 14:21:23 -0700 From: William Lee Irwin III Subject: Re: Why *not* rmap, anyway? Message-ID: <20020507212123.GZ15756@holomorphy.com> References: 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: Daniel Phillips Cc: Rik van Riel , Christian Smith , Joseph A Knapka , "Martin J. Bligh" , linux-mm@kvack.org List-ID: On Tue, May 07, 2002 at 09:43:29PM +0200, Daniel Phillips wrote: > The most obvious place to start are the page table walking operations, of > which there are a half-dozen instances or so. Bill started to do some > work on this, but that ran aground somehow. I think you might run into > the argument 'not broken yet, so don't fix yet'. Still, it would be > worth experimenting with strategies. > Personally, I'd consider such work a diversion from the more important task > of getting rmap implemented. There are a couple of things I should probably say about my prior efforts. The plan back then was to hide the pagetable structure from generic code altogether and allow architecture-specific code to export a procedural interface totally insulating the core from the structure of pagetables. This was largely motivated by the notion that the optimal pagetable structure could be chosen on a per-architecture basis. Linus himself informed me that there was evidence to the contrary regarding architecture-specific optimal pagetable structures, and so I abandoned that effort given the evidence the scheme was pessimal. I have no plans now to change the standardized structure or to export a HAT from arch code. OTOH I've faced some recent reminders of what the code looks like now and believe janitoring may well be in order. 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/