From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 20 May 2001 08:13:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 20 May 2001 08:13:26 -0400 Received: from jurassic.park.msu.ru ([195.208.223.243]:7174 "EHLO jurassic.park.msu.ru") by vger.kernel.org with ESMTP id ; Sun, 20 May 2001 08:13:14 -0400 Date: Sun, 20 May 2001 16:12:34 +0400 From: Ivan Kokshaysky To: Andrea Arcangeli Cc: Richard Henderson , linux-kernel@vger.kernel.org Subject: Re: alpha iommu fixes Message-ID: <20010520161234.B8223@jurassic.park.msu.ru> In-Reply-To: <20010518214617.A701@jurassic.park.msu.ru> <20010519155502.A16482@athlon.random> <20010519231131.A2840@jurassic.park.msu.ru> <20010520044013.A18119@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010520044013.A18119@athlon.random>; from andrea@suse.de on Sun, May 20, 2001 at 04:40:13AM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 20, 2001 at 04:40:13AM +0200, Andrea Arcangeli wrote: > I was only talking about when you get the "pci_map_sg failed" because > you have not 3 but 300 scsi disks connected to your system and you are > writing to all them at the same time allocating zillons of pte, and one > of your drivers (possibly not even a storage driver) is actually not > checking the reval of the pci_map_* functions. You don't need a pte > memleak to trigger it, even regardless of the fact I grown the dynamic > window to 1G which makes it 8 times harder to trigger than in mainline. I think you're too pessimistic. Don't mix "disks" and "controllers" -- SCSI adapter with 10 drives attached is a single DMA agent, not 10 agents. If you're so concerned about Big Iron, go ahead and implement 64-bit PCI support, it would be right long-term solution. I'm pretty sure that high-end servers use mostly this kind of hardware. Oh, well. This doesn't mean that I'm disagreed with what you said. :-) Driver writers must realize that pci mappings are limited resources. Ivan.