From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753510AbXC3O5G (ORCPT ); Fri, 30 Mar 2007 10:57:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753511AbXC3O5G (ORCPT ); Fri, 30 Mar 2007 10:57:06 -0400 Received: from [198.99.130.12] ([198.99.130.12]:57897 "EHLO saraswathi.solana.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753509AbXC3O5F (ORCPT ); Fri, 30 Mar 2007 10:57:05 -0400 Date: Fri, 30 Mar 2007 10:52:57 -0400 From: Jeff Dike To: Andrew Morton Cc: LKML , uml-devel Subject: [PATCH 2/2] UML - Speed up exec Message-ID: <20070330145257.GA5471@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org flush_thread doesn't need to do a full page table walk in order to clear the address space. It knows what the end result needs to be, so it can call unmap directly. This results in a 10-20% speedup in an exec from bash. Signed-off-by: Jeff Dike -- arch/um/kernel/skas/exec.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) Index: linux-2.6.21-mm/arch/um/kernel/skas/exec.c =================================================================== --- linux-2.6.21-mm.orig/arch/um/kernel/skas/exec.c 2007-03-30 10:28:24.000000000 -0400 +++ linux-2.6.21-mm/arch/um/kernel/skas/exec.c 2007-03-30 10:30:15.000000000 -0400 @@ -17,7 +17,17 @@ void flush_thread_skas(void) { - force_flush_all(); + void *data = NULL; + unsigned long end = proc_mm ? task_size : CONFIG_STUB_START; + int ret; + + ret = unmap(¤t->mm->context.skas.id, 0, end, 1, &data); + if(ret){ + printk("flush_thread_skas - clearing address space failed, " + "err = %d\n", ret); + force_sig(SIGKILL, current); + } + switch_mm_skas(¤t->mm->context.skas.id); }