Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762333AbXKQSAO (ORCPT ); Sat, 17 Nov 2007 13:00:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755424AbXKQR76 (ORCPT ); Sat, 17 Nov 2007 12:59:58 -0500 Received: from homer.mvista.com ([63.81.120.158]:60426 "EHLO gateway-1237.mvista.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755265AbXKQR75 (ORCPT ); Sat, 17 Nov 2007 12:59:57 -0500 Subject: Re: [BUG on PREEMPT_RT, 2.6.23.1-rt5] in rt-mutex code and signals From: Daniel Walker To: Ingo Molnar Cc: Remy Bohmer , Steven Rostedt , Thomas Gleixner , RT , linux-kernel In-Reply-To: <20071117174608.GA30641@elte.hu> References: <3efb10970711160751l279fe99dl9f3a130a4373a449@mail.gmail.com> <3efb10970711161502m6216bf5rc19a34184b4f3a2b@mail.gmail.com> <3efb10970711170344n670d8b69w6679d494922c5bb@mail.gmail.com> <1195316550.25393.21.camel@imap.mvista.com> <3efb10970711170909n3acca605j70525e36faf8da7f@mail.gmail.com> <1195320569.25393.38.camel@imap.mvista.com> <20071117174608.GA30641@elte.hu> Content-Type: text/plain Date: Sat, 17 Nov 2007 09:55:40 -0800 Message-Id: <1195322141.25393.41.camel@imap.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-4.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1923 Lines: 54 On Sat, 2007-11-17 at 18:46 +0100, Ingo Molnar wrote: > * Daniel Walker wrote: > > > > Actually, IMO, compat_semaphores behave like semaphores should > > > behave, and thus the same as they behave on a non-RT kernel, and at > > > the locations where the semaphores are now misused as mutexes on RT, > > > we should replace them by differently-named-mutex-type-semaphores, > > > or better: real-RT-mutexes.. > > > > The vast majority of semaphore are actually binary semaphores in the > > Linux kernel .. So it's easier to mass convert semaphores to mutexes, > > then address the ones that don't conform.. Usually they are converted > > to the complete API in mainline.. > > right now there are 3992 mutex_lock() critical sections in the kernel > and only 351 down() based critical sections are left. > > fixing the top 20: > > 4 &vuart_bus_priv.probe_mutex > 5 &connections_lock > 5 &irq_ptr->setting_up_sema > 5 &kbd->sem > 5 &pnp_res_mutex > 5 &port->port_lock > 5 &tq_init_sem > 6 &adb_handler_sem > 6 &dev->parent->sem > 6 &driver_lock > 6 &ha->vport_sem > 7 &big_buffer_sem > 8 &dir_f->sem > 9 &c->alloc_sem > 11 &dev->sem > 11 &usbvision->lock > 12 &c->erase_free_sem > 15 &u132->scheduler_lock > 16 &zfcp_data.config_sema > 17 &f->sem > > would remove 164 of them, so it would convert half of the remaining > semaphore use in the kernel. So the job is almost finished - would > anyone like to go for the final grand feat: complete removal of > semaphores from the kernel? :-) Sure, you want to split the list? Daniel - 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/