Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933475Ab3CZNGp (ORCPT ); Tue, 26 Mar 2013 09:06:45 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:42942 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932263Ab3CZNGm (ORCPT ); Tue, 26 Mar 2013 09:06:42 -0400 From: "Rafael J. Wysocki" To: Oleg Nesterov 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 Date: Tue, 26 Mar 2013 14:14:07 +0100 Message-ID: <3714515.nbfe9U9zSg@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0-rc4+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <20130307175359.GB15631@redhat.com> References: <201303042055.38040.maciej.rutecki@gmail.com> <20130307175305.GA15631@redhat.com> <20130307175359.GB15631@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2456 Lines: 76 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? 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/