From: Toshi Kani <toshi.kani@hp.com>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
isimatu.yasuaki@jp.fujitsu.com,
vasilis.liaskovitis@profitbricks.com
Subject: Re: [PATCH 2/3 RFC] Driver core: Use generic offline/online for CPU offline/online
Date: Tue, 30 Apr 2013 17:42:06 -0600 [thread overview]
Message-ID: <1367365326.16154.139.camel@misato.fc.hp.com> (raw)
In-Reply-To: <5608485.T3GFgtNYov@vostro.rjw.lan>
On Mon, 2013-04-29 at 14:28 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Rework the CPU hotplug code in drivers/base/cpu.c to use the
> generic offline/online support introduced previously instead of
> its own CPU-specific code.
>
> For this purpose, modify cpu_subsys to provide offline and online
> callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling
> the CPU-specific 'online' sysfs attribute.
>
> This modification is not supposed to change the user-observable
> behavior of the kernel (i.e. the 'online' attribute will be present
> in exactly the same place in sysfs and should trigger exactly the
> same actions as before).
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/base/cpu.c | 62 ++++++++++++-----------------------------------------
> 1 file changed, 15 insertions(+), 47 deletions(-)
>
> Index: linux-pm/drivers/base/cpu.c
> ===================================================================
> --- linux-pm.orig/drivers/base/cpu.c
> +++ linux-pm/drivers/base/cpu.c
> @@ -16,66 +16,25 @@
>
> #include "base.h"
>
> -struct bus_type cpu_subsys = {
> - .name = "cpu",
> - .dev_name = "cpu",
> -};
> -EXPORT_SYMBOL_GPL(cpu_subsys);
> -
> static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
>
> #ifdef CONFIG_HOTPLUG_CPU
> -static ssize_t show_online(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static int cpu_subsys_online(struct device *dev)
> {
> - struct cpu *cpu = container_of(dev, struct cpu, dev);
> -
> - return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id));
> + return cpu_up(dev->id);
> }
>
> -static ssize_t __ref store_online(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t count)
> +static int cpu_subsys_offline(struct device *dev)
> {
> - struct cpu *cpu = container_of(dev, struct cpu, dev);
> - ssize_t ret;
> -
> - cpu_hotplug_driver_lock();
By replacing cpu_hotplug_driver_lock() with lock_device_offline() in
patch 1/3, it no longer protects from other places that still use
cpu_hotplug_device_lock(), such as save_mc_for_early().
Thanks,
-Toshi
> - switch (buf[0]) {
> - case '0':
> - ret = cpu_down(cpu->dev.id);
> - if (!ret)
> - kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
> - break;
> - case '1':
> - ret = cpu_up(cpu->dev.id);
> - if (!ret)
> - kobject_uevent(&dev->kobj, KOBJ_ONLINE);
> - break;
> - default:
> - ret = -EINVAL;
> - }
> - cpu_hotplug_driver_unlock();
> -
> - if (ret >= 0)
> - ret = count;
> - return ret;
> + return cpu_down(dev->id);
> }
> -static DEVICE_ATTR(online, 0644, show_online, store_online);
next prev parent reply other threads:[~2013-05-01 0:03 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-29 12:23 [PATCH 0/3 RFC] Driver core / ACPI: Add offline/online for graceful hot-removal of devices Rafael J. Wysocki
2013-04-29 12:26 ` [PATCH 1/3 RFC] Driver core: Add offline/online device operations Rafael J. Wysocki
2013-04-29 23:10 ` Greg Kroah-Hartman
2013-04-30 11:59 ` Rafael J. Wysocki
2013-04-30 15:32 ` Greg Kroah-Hartman
2013-04-30 20:05 ` Rafael J. Wysocki
2013-04-30 23:38 ` Toshi Kani
2013-05-02 0:58 ` Rafael J. Wysocki
2013-05-02 23:29 ` Toshi Kani
2013-05-03 11:48 ` Rafael J. Wysocki
2013-04-29 12:28 ` [PATCH 2/3 RFC] Driver core: Use generic offline/online for CPU offline/online Rafael J. Wysocki
2013-04-29 23:11 ` Greg Kroah-Hartman
2013-04-30 12:01 ` Rafael J. Wysocki
2013-04-30 15:27 ` Greg Kroah-Hartman
2013-04-30 20:06 ` Rafael J. Wysocki
2013-04-30 23:42 ` Toshi Kani [this message]
2013-05-01 14:49 ` Rafael J. Wysocki
2013-05-01 20:07 ` Toshi Kani
2013-05-02 0:26 ` Rafael J. Wysocki
2013-04-29 12:29 ` [PATCH 3/3 RFC] ACPI / hotplug: Use device offline/online for graceful hot-removal Rafael J. Wysocki
2013-04-30 23:49 ` Toshi Kani
2013-05-01 15:05 ` Rafael J. Wysocki
2013-05-01 20:20 ` Toshi Kani
2013-05-02 0:53 ` Rafael J. Wysocki
2013-05-02 12:26 ` [PATCH 0/4] Driver core / ACPI: Add offline/online for graceful hot-removal of devices Rafael J. Wysocki
2013-05-02 12:27 ` [PATCH 1/4] Driver core: Add offline/online device operations Rafael J. Wysocki
2013-05-02 13:57 ` Greg Kroah-Hartman
2013-05-02 23:11 ` Toshi Kani
2013-05-02 23:36 ` Rafael J. Wysocki
2013-05-02 23:23 ` Toshi Kani
2013-05-02 12:28 ` [PATCH 2/4] Driver core: Use generic offline/online for CPU offline/online Rafael J. Wysocki
2013-05-02 13:57 ` Greg Kroah-Hartman
2013-05-02 12:29 ` [PATCH 3/4] ACPI / hotplug: Use device offline/online for graceful hot-removal Rafael J. Wysocki
2013-05-02 12:31 ` [PATCH 4/4] ACPI / processor: Use common hotplug infrastructure Rafael J. Wysocki
2013-05-02 13:59 ` Greg Kroah-Hartman
2013-05-02 23:20 ` Toshi Kani
2013-05-03 12:05 ` Rafael J. Wysocki
2013-05-03 12:21 ` Rafael J. Wysocki
2013-05-03 18:27 ` Toshi Kani
2013-05-03 19:31 ` Rafael J. Wysocki
2013-05-03 19:34 ` Toshi Kani
2013-05-04 1:01 ` [PATCH 0/3 RFC] Driver core: Add offline/online callbacks for memory_subsys Rafael J. Wysocki
2013-05-04 1:03 ` [PATCH 1/3 RFC] ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes Rafael J. Wysocki
2013-05-04 1:04 ` [PATCH 2/3 RFC] Driver core: Introduce types of device "online" Rafael J. Wysocki
2013-05-04 1:06 ` [PATCH 3/3 RFC] Driver core: Introduce offline/online callbacks for memory blocks Rafael J. Wysocki
2013-05-04 11:11 ` [PATCH 0/2 v2, RFC] Driver core: Add offline/online callbacks for memory_subsys Rafael J. Wysocki
2013-05-04 11:12 ` [PATCH 1/2 v2, RFC] ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes Rafael J. Wysocki
2013-05-21 6:50 ` Tang Chen
2013-05-04 11:21 ` [PATCH 2/2 v2, RFC] Driver core: Introduce offline/online callbacks for memory blocks Rafael J. Wysocki
2013-05-06 16:28 ` Vasilis Liaskovitis
2013-05-07 0:59 ` Rafael J. Wysocki
2013-05-07 10:59 ` Vasilis Liaskovitis
2013-05-07 12:11 ` Rafael J. Wysocki
2013-05-07 21:03 ` Toshi Kani
2013-05-07 22:10 ` Rafael J. Wysocki
2013-05-07 22:45 ` Toshi Kani
2013-05-07 23:17 ` Rafael J. Wysocki
2013-05-07 23:59 ` Toshi Kani
2013-05-08 0:24 ` Rafael J. Wysocki
2013-05-08 0:37 ` Toshi Kani
2013-05-08 11:53 ` Rafael J. Wysocki
2013-05-08 14:38 ` Toshi Kani
2013-05-06 17:20 ` Greg Kroah-Hartman
2013-05-06 19:46 ` Rafael J. Wysocki
2013-05-21 6:37 ` Tang Chen
2013-05-21 11:15 ` Rafael J. Wysocki
2013-05-22 4:45 ` Tang Chen
2013-05-22 10:42 ` Rafael J. Wysocki
2013-05-22 22:06 ` [PATCH] Driver core / memory: Simplify __memory_block_change_state() Rafael J. Wysocki
2013-05-22 22:14 ` Greg Kroah-Hartman
2013-05-22 23:29 ` Rafael J. Wysocki
2013-05-23 4:37 ` Tang Chen
2013-05-06 10:48 ` [PATCH 0/2 v2, RFC] Driver core: Add offline/online callbacks for memory_subsys Rafael J. Wysocki
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