From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 25 Sep 2000 22:03:01 +0300 From: Matti Aarnio Subject: Re: the new VMt [4MB+ blocks] Message-ID: <20000925220301.Z11669@mea-ext.zmailer.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from alan@lxorguk.ukuu.org.uk on Mon, Sep 25, 2000 at 06:06:11PM +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: Alan Cox Cc: MM mailing list , linux-kernel@vger.kernel.org List-ID: On Mon, Sep 25, 2000 at 06:06:11PM +0100, Alan Cox wrote: > > > > Stupidity has no limits... > > > Unfortunately its frequently wired into the hardware to save a few cents on > > > scatter gather logic. > > > > Since when hardware folks became exempt from the rule above? 128K is > > almost tolerable, there were requests for 64 _mega_bytes... > > Most cheap ass PCI hardware is built on the basis you can do linear 4Mb > allocations. There is a reason for this. You can do that 4Mb allocation on > NT or Windows 9x Sure, but intel processors have this neat 4 MB "super-page" feature in the MMU... (as we all well know) Sometimes allocating such monster memory blocks could be supported, but it should not be expected to be *fast*. E.g. if doing it in "reliable" way needs possibly moving currently allocated pages away from memory to create such a hole(s), so be it.. Anybody here who can describe those M$ API calls ? Are they kernel/DDK-only, or userspace ones, or both ? /Matti Aarnio -- 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.eu.org/Linux-MM/