Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 9 Mar 2003 21:59:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 9 Mar 2003 21:59:03 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:17938 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Sun, 9 Mar 2003 21:59:02 -0500 Date: Sun, 9 Mar 2003 19:07:36 -0800 (PST) From: Linus Torvalds To: Jamie Lokier cc: linux-kernel@vger.kernel.org, Subject: Re: [Bug 350] New: i386 context switch very slow compared to 2.4 due to wrmsr (performance) In-Reply-To: <20030212101206.GA10422@bjl1.jlokier.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 26 Ok Jamie, since you've been interested in the past, I thought I'd ask you to test the current context switch stuff. Andi cleaned up some FPU reload stuff (and I fixed a bug in it, tssk tssk Andi - you'd obviously not actually timed your cleanups), and I just committed and pushed out my "cache the value of SYSENTER_CS in the TSS" patch. It won't bring context switching back to where it _could_ be, but it should be noticeably better. My pipe bandwidth is up from under 600MB/s to about ~700MB/s according to lmbench. Your SYSENTER_ESP hack would probably get back the rest, but I haven't seen any patches for it, hint hint. In the meantime, we're almost back to where we were _and_ we support sysenter (ie my system calls are down by almost a factor of four). So we're doing pretty well. Linus - 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/