From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946812AbXD3UiA (ORCPT ); Mon, 30 Apr 2007 16:38:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946810AbXD3Uh7 (ORCPT ); Mon, 30 Apr 2007 16:37:59 -0400 Received: from rtr.ca ([64.26.128.89]:3856 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946806AbXD3Uh5 (ORCPT ); Mon, 30 Apr 2007 16:37:57 -0400 Message-ID: <463653A3.5040606@rtr.ca> Date: Mon, 30 Apr 2007 16:37:55 -0400 From: Mark Lord User-Agent: Thunderbird 2.0.0.0 (X11/20070326) MIME-Version: 1.0 To: Linux Kernel , tglx@linutronix.de Cc: Linus Torvalds Subject: Re: [BUG] 2.6.21: Kernel won't boot with either/both of CONFIG_NO_HZ, CONFIG_HIGH_RES_TIMERS References: <46364EBC.5050804@rtr.ca> <46364F5A.2030208@rtr.ca> In-Reply-To: <46364F5A.2030208@rtr.ca> 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 Mark Lord wrote: > Mark Lord wrote: >> I have a new notebook (Dell Inspiron 9400) with Core2-Duo T7400 @ 2.1Ghz. >> When either/both of CONFIG_NO_HZ, CONFIG_HIGH_RES_TIMERS is used, >> the 2.6.21 kernel hangs on startup just after printing one/both of these: > .. > > That's a hard hang, by the way. No magic sysrq key or anything. I've now built a kernel with the same config, plus all of the kernel debug options, and this one boots. I think this means the lockups may be due to a very tight race condition somewhere, and adding all of the debug goodies was enough to slow it down and avoid the clash (?) One thing I notice from the syslog, is that with this kernel there is only the one "switched to high resolution mode on cpu 0" message, rather than one per-CPU as on the failed kernel. Here's the diff for the debug config that works: --- dot_config.nfg 2007-04-30 16:33:31.000000000 -0400 +++ dot_config.boots 2007-04-30 16:22:48.000000000 -0400 @@ -1,7 +1,7 @@ # # Automatically generated make config: don't edit # Linux kernel version: 2.6.21 -# Mon Apr 30 15:42:53 2007 +# Mon Apr 30 16:22:48 2007 # CONFIG_X86_32=y CONFIG_GENERIC_TIME=y @@ -56,7 +56,7 @@ CONFIG_UID16=y CONFIG_SYSCTL_SYSCALL=y CONFIG_KALLSYMS=y -# CONFIG_KALLSYMS_ALL is not set +CONFIG_KALLSYMS_ALL=y # CONFIG_KALLSYMS_EXTRA_PASS is not set CONFIG_HOTPLUG=y CONFIG_PRINTK=y @@ -2418,39 +2418,45 @@ # CONFIG_DEBUG_FS is not set # CONFIG_HEADERS_CHECK is not set CONFIG_DEBUG_KERNEL=y -# CONFIG_DEBUG_SHIRQ is not set +CONFIG_DEBUG_SHIRQ=y CONFIG_LOG_BUF_SHIFT=16 -# CONFIG_DETECT_SOFTLOCKUP is not set +CONFIG_DETECT_SOFTLOCKUP=y # CONFIG_SCHEDSTATS is not set # CONFIG_TIMER_STATS is not set -# CONFIG_DEBUG_SLAB is not set -# CONFIG_DEBUG_PREEMPT is not set -# CONFIG_DEBUG_RT_MUTEXES is not set +CONFIG_DEBUG_SLAB=y +CONFIG_DEBUG_SLAB_LEAK=y +CONFIG_DEBUG_PREEMPT=y +CONFIG_DEBUG_RT_MUTEXES=y +CONFIG_DEBUG_PI_LIST=y # CONFIG_RT_MUTEX_TESTER is not set -# CONFIG_DEBUG_SPINLOCK is not set -# CONFIG_DEBUG_MUTEXES is not set -# CONFIG_DEBUG_LOCK_ALLOC is not set -# CONFIG_PROVE_LOCKING is not set -# CONFIG_DEBUG_SPINLOCK_SLEEP is not set -# CONFIG_DEBUG_LOCKING_API_SELFTESTS is not set -# CONFIG_DEBUG_KOBJECT is not set -# CONFIG_DEBUG_HIGHMEM is not set +CONFIG_DEBUG_SPINLOCK=y +CONFIG_DEBUG_MUTEXES=y +CONFIG_DEBUG_LOCK_ALLOC=y +CONFIG_PROVE_LOCKING=y +CONFIG_LOCKDEP=y +# CONFIG_DEBUG_LOCKDEP is not set +CONFIG_TRACE_IRQFLAGS=y +CONFIG_DEBUG_SPINLOCK_SLEEP=y +CONFIG_DEBUG_LOCKING_API_SELFTESTS=y +CONFIG_STACKTRACE=y +CONFIG_DEBUG_KOBJECT=y +CONFIG_DEBUG_HIGHMEM=y CONFIG_DEBUG_BUGVERBOSE=y # CONFIG_DEBUG_INFO is not set -# CONFIG_DEBUG_VM is not set -# CONFIG_DEBUG_LIST is not set -# CONFIG_FRAME_POINTER is not set +CONFIG_DEBUG_VM=y +CONFIG_DEBUG_LIST=y +CONFIG_FRAME_POINTER=y CONFIG_FORCED_INLINING=y # CONFIG_RCU_TORTURE_TEST is not set # CONFIG_FAULT_INJECTION is not set -# CONFIG_EARLY_PRINTK is not set -# CONFIG_DEBUG_STACKOVERFLOW is not set +CONFIG_EARLY_PRINTK=y +CONFIG_DEBUG_STACKOVERFLOW=y # CONFIG_DEBUG_STACK_USAGE is not set # # Page alloc debug is incompatible with Software Suspend on i386 # -# CONFIG_DEBUG_RODATA is not set +CONFIG_DEBUG_RODATA=y # CONFIG_4KSTACKS is not set CONFIG_X86_FIND_SMP_CONFIG=y CONFIG_X86_MPPARSE=y