Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752286AbZGVPMR (ORCPT ); Wed, 22 Jul 2009 11:12:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751891AbZGVPMR (ORCPT ); Wed, 22 Jul 2009 11:12:17 -0400 Received: from e28smtp05.in.ibm.com ([59.145.155.5]:38805 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbZGVPMQ (ORCPT ); Wed, 22 Jul 2009 11:12:16 -0400 Date: Wed, 22 Jul 2009 20:41:23 +0530 From: "K.Prasad" To: Ingo Molnar , Peter Zijlstra Cc: Thomas Gleixner , LKML , Frederic Weisbecker , Steven Rostedt Subject: Fix traceback seen when resuming after suspend-to-ram Message-ID: <20090722151123.GA4934@in.ibm.com> Reply-To: prasad@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1961 Lines: 55 Hi Ingo, Please accept a patch that fixes the warning message and traceback seen upon a resume after suspend-to-ram. The warning message is emitted because spin_unlock_bh()<--load_debug_registers() is invoked with interrupts disabled upon 'resume' unlike when invoked at boot-time, and was reported on LKML here: http://lkml.org/lkml/2009/7/18/145. This patch modifies load_debug_registers() to block all interrupts and not just bottom-halves (bottom-halves were blocked in load_debug_registers() prevent flush_thread_hw_breakpoint() from interfering when invoked from SoftIRQ context). Fix traceback seen when resuming after suspend-to-ram This patch fixes a traceback when resuming after a suspend-to-ram operation. The traceback warns about entering slowpatch due to a spin_unlock_bh() done from interrupt context. Signed-off-by: K.Prasad --- kernel/hw_breakpoint.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) Index: linux-2.6-tip/kernel/hw_breakpoint.c =================================================================== --- linux-2.6-tip.orig/kernel/hw_breakpoint.c +++ linux-2.6-tip/kernel/hw_breakpoint.c @@ -80,17 +80,15 @@ void load_debug_registers(void) unsigned long flags; struct task_struct *tsk = current; - spin_lock_bh(&hw_breakpoint_lock); - /* Prevent IPIs for new kernel breakpoint updates */ - local_irq_save(flags); + spin_lock_irqsave(&hw_breakpoint_lock, flags); + arch_update_kernel_hw_breakpoint(NULL); - local_irq_restore(flags); if (test_tsk_thread_flag(tsk, TIF_DEBUG)) arch_install_thread_hw_breakpoint(tsk); - spin_unlock_bh(&hw_breakpoint_lock); + spin_unlock_irqrestore(&hw_breakpoint_lock, flags); } /* -- 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/