Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 15 Jan 2002 16:06:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 15 Jan 2002 16:06:10 -0500 Received: from quark.didntduck.org ([216.43.55.190]:60683 "EHLO quark.didntduck.org") by vger.kernel.org with ESMTP id ; Tue, 15 Jan 2002 16:05:55 -0500 Message-ID: <3C4499A3.781E5A85@didntduck.org> Date: Tue, 15 Jan 2002 16:05:39 -0500 From: Brian Gerst X-Mailer: Mozilla 4.76 [en] (WinNT; U) X-Accept-Language: en MIME-Version: 1.0 To: Peter Zaitsev CC: Linux Kernel List Subject: Re: 3.5G user space speed In-Reply-To: <16247691406.20020115234737@spylog.ru> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Peter Zaitsev wrote: > > Hello Linux, > > 2.4.xaa Series as well as SuSE kernels have 3.5G userspace option, > which seems to be quite useful, therefore I see it's not included > is stock kernel for some reasons. Also I've heard this > configuration may have some performance problems. > > Can anyone comment on this topic ? > > I need large amount of address space for my application but I also > need to get as much I/O performance as it's possible, so I can switch > to 3.0/1.0 memory distribution if it will benefit here. You can't have it both ways with the x86 (speed vs. large userspace). Kernel 2.5 may help a bit here because changes were made to allow DMA from all memory (subject to card limitations), lessening the burden for direct-mapped memory. Otherwise you'll need to move to a 64-bit arch. -- Brian Gerst - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/