Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933788Ab3CZNLu (ORCPT ); Tue, 26 Mar 2013 09:11:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43269 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758085Ab3CZNLs (ORCPT ); Tue, 26 Mar 2013 09:11:48 -0400 Date: Tue, 26 Mar 2013 14:09:19 +0100 From: Oleg Nesterov To: "Rafael J. Wysocki" Cc: Henrique de Moraes Holschuh , Mandeep Singh Baines , Linux Kernel Mailing List , linux-acpi@vger.kernel.org, ibm-acpi@hmh.eng.br, ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, Aaron Lu , Tejun Heo , Andrew Morton , Artem Savkov Subject: Re: [PATCH 1/1] thinkpad-acpi: kill hotkey_thread_mutex Message-ID: <20130326130918.GA29941@redhat.com> References: <201303042055.38040.maciej.rutecki@gmail.com> <20130307175305.GA15631@redhat.com> <20130307175359.GB15631@redhat.com> <3714515.nbfe9U9zSg@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3714515.nbfe9U9zSg@vostro.rjw.lan> 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: 2669 Lines: 85 On 03/26, Rafael J. Wysocki wrote: > > On Thursday, March 07, 2013 06:53:59 PM Oleg Nesterov wrote: > > hotkey_kthread() does try_to_freeze() under hotkey_thread_mutex. > > > > We can simply kill this mutex, hotkey_poll_stop_sync() does not need > > to serialize with hotkey_kthread(). When kthread_stop() returns the > > thread is already dead, it called do_exit()->complete_vfork_done(). > > > > Reported-by: Artem Savkov > > Reported-by: Maciej Rutecki > > Signed-off-by: Oleg Nesterov > > I wonder if anyone is taking care of this patch? IIRC, it is already in -mm tree. > Rafael > > > > --- x/drivers/platform/x86/thinkpad_acpi.c > > +++ x/drivers/platform/x86/thinkpad_acpi.c > > @@ -1965,9 +1965,6 @@ struct tp_nvram_state { > > /* kthread for the hotkey poller */ > > static struct task_struct *tpacpi_hotkey_task; > > > > -/* Acquired while the poller kthread is running, use to sync start/stop */ > > -static struct mutex hotkey_thread_mutex; > > - > > /* > > * Acquire mutex to write poller control variables as an > > * atomic block. > > @@ -2463,8 +2460,6 @@ static int hotkey_kthread(void *data) > > unsigned int poll_freq; > > bool was_frozen; > > > > - mutex_lock(&hotkey_thread_mutex); > > - > > if (tpacpi_lifecycle == TPACPI_LIFE_EXITING) > > goto exit; > > > > @@ -2524,7 +2519,6 @@ static int hotkey_kthread(void *data) > > } > > > > exit: > > - mutex_unlock(&hotkey_thread_mutex); > > return 0; > > } > > > > @@ -2534,9 +2528,6 @@ static void hotkey_poll_stop_sync(void) > > if (tpacpi_hotkey_task) { > > kthread_stop(tpacpi_hotkey_task); > > tpacpi_hotkey_task = NULL; > > - mutex_lock(&hotkey_thread_mutex); > > - /* at this point, the thread did exit */ > > - mutex_unlock(&hotkey_thread_mutex); > > } > > } > > > > @@ -3235,7 +3226,6 @@ static int __init hotkey_init(struct ibm > > mutex_init(&hotkey_mutex); > > > > #ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL > > - mutex_init(&hotkey_thread_mutex); > > mutex_init(&hotkey_thread_data_mutex); > > #endif > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/