From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751259AbVK3PAO (ORCPT ); Wed, 30 Nov 2005 10:00:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751261AbVK3PAO (ORCPT ); Wed, 30 Nov 2005 10:00:14 -0500 Received: from rtsoft3.corbina.net ([85.21.88.6]:1550 "EHLO buildserver.ru.mvista.com") by vger.kernel.org with ESMTP id S1751259AbVK3PAN (ORCPT ); Wed, 30 Nov 2005 10:00:13 -0500 Message-ID: <438DBE4B.4000709@ru.mvista.com> Date: Wed, 30 Nov 2005 17:59:23 +0300 From: Valentine Barshak User-Agent: Mozilla Thunderbird 1.0.2-1.3.3 (X11/20050513) X-Accept-Language: en-us, en MIME-Version: 1.0 To: lkml CC: Ingo Molnar Subject: [patch] linux-2.6.14-rt21 PPC32 signal delivery in realtime preemption. Content-Type: multipart/mixed; boundary="------------010900090809060105070907" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------010900090809060105070907 Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Patch description: With CONFIG_PREEMPT_RT=y and CONFIG_DEBUG_PREEMPT=y lots of sleeping-in-invalid-context BUG messages are displayed for PPC32 architecture. Kernel log: Freeing unused kernel memory: 108k init BUG: sleeping function called from invalid context init(1) at kernel/rt.c:1446 in_atomic():1 [00000001], irqs_disabled():0 Call trace: [c0012010] __might_sleep+0xf0/0xfc [c0031fd8] __spin_lock+0x38/0x70 [c004ab68] lru_cache_add_active+0x20/0xa0 [c0071c24] install_arg_page+0xf0/0x24c [c0071ee8] setup_arg_pages+0x168/0x1d4 [c0095674] load_elf_binary+0x44c/0x11d8 [c0072ff4] search_binary_handler+0xfc/0x338 [c00733c0] do_execve+0x190/0x274 [c0005b30] sys_execve+0x80/0xe0 [c0002474] ret_from_syscall+0x0/0x70 [c00050b8] execve+0x8/0x30 [c00016a8] init+0x1b0/0x248 [c0005090] original_kernel_thread+0x48/0x64 This happens because interrupts are not enabled in the realtime preemption mode by the time kernel delivers signals to processes. This patch enables interrupts so that realtime mutexes can be acquired in the "right" context. The original code has been found in CONFIG_PREEMPT_RT support for i386 architecture. Thanks. Signed-off-by: Valentine Barshak --------------010900090809060105070907 Content-Type: text/x-patch; name="ppc_premmpt_rt_signal.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="ppc_premmpt_rt_signal.patch" diff -rauN linux-2.6.14.orig/arch/ppc/kernel/signal.c linux-2.6.14/arch/ppc/kernel/signal.c --- linux-2.6.14.orig/arch/ppc/kernel/signal.c 2005-10-28 04:02:08.000000000 +0400 +++ linux-2.6.14/arch/ppc/kernel/signal.c 2005-11-30 17:24:15.268137752 +0300 @@ -705,6 +705,14 @@ unsigned long frame, newsp; int signr, ret; +#ifdef CONFIG_PREEMPT_RT + /* + * Fully-preemptible kernel does not need interrupts disabled: + */ + local_irq_enable(); + preempt_check_resched(); +#endif + if (try_to_freeze()) { signr = 0; if (!signal_pending(current)) --------------010900090809060105070907--