Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935028AbXHHOVD (ORCPT ); Wed, 8 Aug 2007 10:21:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935303AbXHHOUo (ORCPT ); Wed, 8 Aug 2007 10:20:44 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:20966 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935286AbXHHOUm (ORCPT ); Wed, 8 Aug 2007 10:20:42 -0400 Message-ID: <46B9D08F.8080402@openvz.org> Date: Wed, 08 Aug 2007 18:17:51 +0400 From: Pavel Emelyanov User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Andrew Morton CC: linux-arch@vger.kernel.org, Linux Kernel Mailing List , devel@openvz.org Subject: [PATCH] Add ability to print calltraces tighter on i386 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2979 Lines: 95 When printing a BUG or OOPS report the longest part of it is the calltrace, which sometimes (quite often) doesn't fit the standard 25-lines display. This may become a bad news when the system doesn't have a serial/net console and is completely frozen so that the terminal scrolling doesn't work. The information that hides from the developer is registers, the top of the calltrace and information about the kernel and the crashed process (uname). As our experience shows, seeing this info is sometimes critical and having a short calltrace would help a lot. The proposal is to make a boot-option called "tight_trace", that makes the calltrace show only the addresses in one line instead of the symbol names one per line. E.g. OOPSes of 50 lines occupy ~20 with this patch. This is an example of how it will look for i386, but if this will be found useful, I will make the patch for other arched I can test it on (at least x86_64, ia64). Signed-off-by: Pavel Emelyanov --- arch/i386/kernel/traps.c | 29 +++++++++++++++++++++++++---- 1 files changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index f469d20..8aa2b3b 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -186,6 +186,19 @@ void dump_trace(struct task_struct *task } EXPORT_SYMBOL(dump_trace); +static int decode_oops = 1; + +static int __init setup_decode_oops(char *str) +{ + if (*str) + return 0; + + decode_oops = 0; + return 1; +} + +__setup("tight_trace", setup_decode_oops); + static void print_trace_warning_symbol(void *data, char *msg, unsigned long symbol) { @@ -209,8 +222,11 @@ static int print_trace_stack(void *data, */ static void print_trace_address(void *data, unsigned long addr) { - printk("%s [<%08lx>] ", (char *)data, addr); - print_symbol("%s\n", addr); + if (decode_oops) { + printk("%s [<%08lx>] ", (char *)data, addr); + print_symbol("%s\n", addr); + } else + printk("[<%08lx>] ", addr); touch_nmi_watchdog(); } @@ -226,7 +242,9 @@ show_trace_log_lvl(struct task_struct *t unsigned long * stack, char *log_lvl) { dump_trace(task, regs, stack, &print_trace_ops, log_lvl); - printk("%s =======================\n", log_lvl); + if (decode_oops) + printk("%s =======================", log_lvl); + printk("\n"); } void show_trace(struct task_struct *task, struct pt_regs *regs, @@ -256,7 +274,10 @@ static void show_stack_log_lvl(struct ta printk("\n%s ", log_lvl); printk("%08lx ", *stack++); } - printk("\n%sCall Trace:\n", log_lvl); + printk("\n%sCall Trace: ", log_lvl); + if (decode_oops) + printk("\n"); + show_trace_log_lvl(task, regs, esp, log_lvl); debug_show_held_locks(task); } - 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/