From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 9 Dec 1999 21:39:45 +0100 (CET) From: Rik van Riel Subject: Re: Getting big areas of memory, in 2.3.x? In-Reply-To: <199912092031.MAA40950@google.engr.sgi.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Kanoj Sarcar Cc: Jeff Garzik , mingo@chiara.csoma.elte.hu, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: On Thu, 9 Dec 1999, Kanoj Sarcar wrote: > > Ingo Molnar wrote: > > > hm, does anyone have any conceptual problem with a new > > > allocate_largemem(pages) interface in page_alloc.c? It's not terribly hard > > > to scan all bitmaps for available RAM and mark the large memory area > > > allocated and remove all pages from the freelists. Such areas can only be > > > freed via free_largemem(pages). Both calls will be slow, so should be only > > > used at driver initialization time and such. > > > > Would this interface swap out user pages if necessary? That sort of > > interface would be great, and kill a number of hacks floating around out > > there. > > Swapping out user pages is not a sure shot thing unless Linux implements > reverse maps, so that we can track which page is being used by which pte. > > Without rmaps, any possible solution will be quite costly, if not an > outright hack, IMO. Not only that, we would also need to make sure that no kernel data pages are in the way. This means we'll need both reverse maps and a "real" zoned allocator. Not a 2.4 thing, I'm afraid :( Rik -- The Internet is not a network of computers. It is a network of people. That is its real strength. -- 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/