Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762441Ab2KAXLc (ORCPT ); Thu, 1 Nov 2012 19:11:32 -0400 Received: from ogre.sisk.pl ([193.178.161.156]:51429 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759292Ab2KAXL3 (ORCPT ); Thu, 1 Nov 2012 19:11:29 -0400 From: "Rafael J. Wysocki" To: Yinghai Lu Cc: Toshi Kani , ZhangRui , Andrew Morton , Len Brown , Tang Chen , bhelgaas@google.com, jiang.liu@huawei.com, izumi.taku@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/3] Improve container_notify_cb() to support container hot-remove. Date: Fri, 02 Nov 2012 00:15:35 +0100 Message-ID: <1920067.RxMJtDGai1@vostro.rjw.lan> User-Agent: KMail/4.8.5 (Linux/3.7.0-rc3; KDE/4.8.5; x86_64; ; ) In-Reply-To: References: <1351668471-31436-1-git-send-email-tangchen@cn.fujitsu.com> <11976302.Ya3MGGIAsU@vostro.rjw.lan> 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: 2960 Lines: 92 On Thursday, November 01, 2012 03:15:31 PM Yinghai Lu wrote: > On Thu, Nov 1, 2012 at 2:31 PM, Rafael J. Wysocki wrote: > >> oh, no, that commit should not be reverted. instead we should add some > >> comment for it... > >> > >> that mean : three path, will have three separated static lock dep key > >> from every INIT_WORK. > > > > I see. > > > > OK, I'll drop the patch removing it. > > > > What about the following comment: > > > > "To prevent lockdep from complaining unnecessarily, make sure that there > > is a different static lockdep key created for each workqueue by using > > INIT_WORK for each of them separately." > > > created ? > > how about "defined" ? > > or just remove "created" Yes, that's better. I suppose that the appended patch may be better still, though. Thanks, Rafael --- From: Rafael J. Wysocki Subject: ACPI: Make seemingly useless check in osl.c more understandable There is a seemingly useless check in drivers/acpi/osl.c added by commit bc73675 (ACPI: fixes a false alarm from lockdep), which really is necessary to avoid false positive lockdep complaints. Document this and rearrange the code related to it so that it makes fewer checks. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/osl.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) Index: linux/drivers/acpi/osl.c =================================================================== --- linux.orig/drivers/acpi/osl.c +++ linux/drivers/acpi/osl.c @@ -944,17 +944,24 @@ static acpi_status __acpi_os_execute(acp * because the hotplug code may call driver .remove() functions, * which invoke flush_scheduled_work/acpi_os_wait_events_complete * to flush these workqueues. + * + * To prevent lockdep from complaining unnecessarily, make sure that + * there is a different static lockdep key for each workqueue by using + * INIT_WORK() for each of them separately. */ - queue = hp ? kacpi_hotplug_wq : - (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq); - dpc->wait = hp ? 1 : 0; - - if (queue == kacpi_hotplug_wq) + if (hp) { + queue = kacpi_hotplug_wq; + dpc->wait = 1; INIT_WORK(&dpc->work, acpi_os_execute_deferred); - else if (queue == kacpi_notify_wq) + } else if (type == OSL_NOTIFY_HANDLER) { + queue = kacpi_notify_wq; + dpc->wait = 0; INIT_WORK(&dpc->work, acpi_os_execute_deferred); - else + } else { + queue = kacpid_wq; + dpc->wait = 0; INIT_WORK(&dpc->work, acpi_os_execute_deferred); + } /* * On some machines, a software-initiated SMI causes corruption unless -- 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/