On Thu, Nov 1, 2012 at 1:17 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > On Thursday, November 01, 2012 01:17:58 PM Toshi Kani wrote: >> On Thu, 2012-11-01 at 11:28 -0700, Yinghai Lu wrote: >> > On Thu, Nov 1, 2012 at 9:43 AM, Toshi Kani <toshi.kani@xxxxxx> wrote: >> > > >> > > Rafael pointed out in my CPU hot-remove patch that >> > > acpi_bus_hot_remove_device() was not exported for modules. Looks like >> > > you have the same problem here. FYI, I just sent the following patch >> > > that exports acpi_bus_hot_remove_device() and acpi_os_hotplug_execute(). >> > > >> > > https://lkml.org/lkml/2012/11/1/225 >> > >> > acpi_os_hotplug_execute() does not like having good quality yet. >> > >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 941) /* >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 942) * We >> > can't run hotplug code in keventd_wq/kacpid_wq/kacpid_notify_wq >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 943) * >> > because the hotplug code may call driver .remove() functions, >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 944) * >> > which invoke flush_scheduled_work/acpi_os_wait_events_complete >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 945) * to >> > flush these workqueues. >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 946) */ >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 947) queue >> > = hp ? kacpi_hotplug_wq : >> > c02256be (Zhang Rui 2009-06-23 10:20:29 +0800 948) >> > (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq); >> > 9ac61856 (Bjorn Helgaas 2009-08-31 22:32:10 +0000 949) >> > dpc->wait = hp ? 1 : 0; >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 950) >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 951) if >> > (queue == kacpi_hotplug_wq) >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 952) >> > INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 953) else >> > if (queue == kacpi_notify_wq) >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 954) >> > INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 955) else >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 956) >> > INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > bc73675b (Zhang Rui 2010-03-22 15:48:54 +0800 957) >> > >> > really don't know why checking queue and call same code in every branch. >> > >> > from comm: >> > >> > commit bc73675b99fd9850dd914be01d71af99c5d2a1ae >> > Author: Zhang Rui <rui.zhang@xxxxxxxxx> >> > Date: Mon Mar 22 15:48:54 2010 +0800 >> > >> > ACPI: fixes a false alarm from lockdep >> > >> > fixes a false alarm from lockdep, as acpi hotplug workqueue waits other >> > workqueues. >> > http://bugzilla.kernel.org/show_bug.cgi?id=14553 >> > https://bugzilla.kernel.org/show_bug.cgi?id=15521 >> > >> > Original-patch-from: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >> > Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx> >> > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> >> > Signed-off-by: Len Brown <len.brown@xxxxxxxxx> >> > >> > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c >> > index 8e6d866..900da68 100644 >> > --- a/drivers/acpi/osl.c >> > +++ b/drivers/acpi/osl.c >> > @@ -758,7 +758,14 @@ static acpi_status >> > __acpi_os_execute(acpi_execute_type type, >> > queue = hp ? kacpi_hotplug_wq : >> > (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq); >> > dpc->wait = hp ? 1 : 0; >> > - INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > + >> > + if (queue == kacpi_hotplug_wq) >> > + INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > + else if (queue == kacpi_notify_wq) >> > + INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > + else >> > + INIT_WORK(&dpc->work, acpi_os_execute_deferred); >> > + >> > ret = queue_work(queue, &dpc->work); >> > >> > if (!ret) { >> > >> > >> > Len or Rafael, >> > can you just revert that silly patch? >> >> Hi Yinghai, >> >> Per the following thread, the code seems to be written in this way to >> allocate a separate lock_class_key for each work queue. It should have >> had some comment to explain this, though. >> >> https://lkml.org/lkml/2009/12/13/304 > > The code has evolved since then, however, so that it doesn't make sense > any more. > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
