From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 16 Aug 1999 23:39:12 -0700 (PDT) From: Linus Torvalds Subject: Re: [bigmem-patch] 4GB with Linux on IA32 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Alan Cox , Kanoj Sarcar , sct@redhat.com, Gerhard.Wichert@pdb.siemens.de, Winfried.Gerhard@pdb.siemens.de, linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: On Tue, 17 Aug 1999, Andrea Arcangeli wrote: > > This other incremental patch will make the bigmem code safe w.r.t. raw-io: Well, it makes it safe, but doesn't actually make it _work_. As such, it's not very usable. I suspect it had better be our current fix, though. I also suspect that we can't just break all drivers, so for now I would just make this work for anonymous pages and ignore direct-IO. The driver issue is going to need some serious thinking, and doing it for anonymous pages only may be enough for many things. Especially if anonymous pages _prefer_ the high-memory pages. Oh, and copied-on-write pages count as anonymous, I assume you did that already (ie when you allocate a new page and copy the old contents into it, you might as well consider the new page to be anonymous, even though it gets its initial data from a potentially non-anonymous page). Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/