Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759463AbXKBPme (ORCPT ); Fri, 2 Nov 2007 11:42:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758525AbXKBPlc (ORCPT ); Fri, 2 Nov 2007 11:41:32 -0400 Received: from [198.99.130.12] ([198.99.130.12]:60102 "EHLO saraswathi.solana.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1758494AbXKBPlb (ORCPT ); Fri, 2 Nov 2007 11:41:31 -0400 Date: Fri, 2 Nov 2007 11:40:15 -0400 From: Jeff Dike To: Andrew Morton Cc: Joe Perches , LKML , uml-devel Subject: [PATCH 6/6] UML - get_wchan fixes Message-ID: <20071102154015.GA10288@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1962 Lines: 53 [ This can be merged with uml-implement-get_wchan.patch ] The previous get_wchan patch needed some more work. Joe Perches suggested the use of bool where I was using a counter. It also turned out not to work so well on x86_64, so I changed the algorithm a bit. Instead of skipping one frame and looking for the next non-sched symbol, it now looks for at least one scheduler frame, then returns the first symbol seen above that. Signed-off-by: Jeff Dike --- arch/um/kernel/process.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) Index: linux-2.6.22/arch/um/kernel/process.c =================================================================== --- linux-2.6.22.orig/arch/um/kernel/process.c 2007-10-31 13:16:40.000000000 -0400 +++ linux-2.6.22/arch/um/kernel/process.c 2007-10-31 13:17:00.000000000 -0400 @@ -462,7 +462,8 @@ unsigned long arch_align_stack(unsigned unsigned long get_wchan(struct task_struct *p) { - unsigned long stack_page, sp, ip, count = 0; + unsigned long stack_page, sp, ip; + bool seen_sched = 0; if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) return 0; @@ -482,14 +483,11 @@ unsigned long get_wchan(struct task_stru while (sp < stack_page + THREAD_SIZE) { ip = *((unsigned long *) sp); - if (kernel_text_address(ip) && !in_sched_functions(ip)) { - /* - * Skip one valid IP, which will be the low-level UML - * context switcher. - */ - if (count++ == 1) - return ip; - } + if (in_sched_functions(ip)) + /* Ignore everything until we're above the scheduler */ + seen_sched = 1; + else if (kernel_text_address(ip) && seen_sched) + return ip; sp += sizeof(unsigned long); } - 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/