Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753031Ab0FZJUW (ORCPT ); Sat, 26 Jun 2010 05:20:22 -0400 Received: from v-smtp-auth-relay-3.gradwell.net ([79.135.125.42]:55451 "EHLO v-smtp-auth-relay-3.gradwell.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752245Ab0FZJUV convert rfc822-to-8bit (ORCPT ); Sat, 26 Jun 2010 05:20:21 -0400 Subject: Atom N270 more efficent with int 0x80 than with syscalls From: Alex Buell Reply-To: alex.buell@munted.org.uk To: Mailing Lists - Kernel Developers Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Organization: One very high maintenance cat for company Date: Sat, 26 Jun 2010 10:20:11 +0100 Message-ID: <1277544011.24284.14.camel@lithium.local.net> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1051 Lines: 24 Recently I rewrote a small assembler program to test timings and print out timing informations for various assembly routines. Then I thought to add tests for timings on int 0x80 and calling via syscalls. Now I know int 0x80 calls are expensive on processors such as the Pentium IV but someone has tested my assembly program with their Atom N270 1.6GHz system, and int 0x80s calls are actually much quicker than syscalls on these processors. Here's the test program that exposed the timing differences with these int 0x80 calls and syscalls: http://www.munted.org.uk/programming/newtimer.zip Perhaps the kernel could be greatly speeded up on certain processors if it dynamically adapts to use the quickest type of system calls? -- http://www.munted.org.uk One very high maintenance cat living here. -- 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/