2014-02-02 03:17:39

by Zoran Markovic

[permalink] [raw]
Subject: [RFC PATCHv2] usb: move hub init and LED blink work to power efficient workqueue

From: Shaibal Dutta <[email protected]>

Allow the scheduler to select the best CPU to handle hub initalization
and LED blinking work. This extends idle residency times on idle CPUs
and conserves power.

This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected.

Cc: Greg Kroah-Hartman <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Sarah Sharp <[email protected]>
Cc: Xenia Ragiadakou <[email protected]>
Cc: Julius Werner <[email protected]>
Cc: Krzysztof Mazur <[email protected]>
Cc: Matthias Beyer <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Mathias Nyman <[email protected]>
Cc: Thomas Pugliese <[email protected]>
Signed-off-by: Shaibal Dutta <[email protected]>
[[email protected]: Rebased to latest kernel. Added commit message.
Changed reference from system to power efficient workqueue for LEDs in
check_highspeed() and hub_port_connect_change().]
Signed-off-by: Zoran Markovic <[email protected]>
---
drivers/usb/core/hub.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index babba88..e11a7e9 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -504,7 +504,8 @@ static void led_work (struct work_struct *work)
changed++;
}
if (changed)
- schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
+ queue_delayed_work(system_power_efficient_wq,
+ &hub->leds, LED_CYCLE_PERIOD);
}

/* use a short timeout for hub/port status fetches */
@@ -1046,7 +1047,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
if (type == HUB_INIT) {
delay = hub_power_on(hub, false);
PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
- schedule_delayed_work(&hub->init_work,
+ queue_delayed_work(system_power_efficient_wq,
+ &hub->init_work,
msecs_to_jiffies(delay));

/* Suppress autosuspend until init is done */
@@ -1200,7 +1202,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
/* Don't do a long sleep inside a workqueue routine */
if (type == HUB_INIT2) {
PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
- schedule_delayed_work(&hub->init_work,
+ queue_delayed_work(system_power_efficient_wq,
+ &hub->init_work,
msecs_to_jiffies(delay));
return; /* Continues at init3: below */
} else {
@@ -1214,7 +1217,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
if (status < 0)
dev_err(hub->intfdev, "activate --> %d\n", status);
if (hub->has_indicators && blinkenlights)
- schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
+ queue_delayed_work(system_power_efficient_wq,
+ &hub->leds, LED_CYCLE_PERIOD);

/* Scan all ports that need attention */
kick_khubd(hub);
@@ -4316,7 +4320,8 @@ check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
/* hub LEDs are probably harder to miss than syslog */
if (hub->has_indicators) {
hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
- schedule_delayed_work (&hub->leds, 0);
+ queue_delayed_work(system_power_efficient_wq,
+ &hub->leds, 0);
}
}
kfree(qual);
@@ -4545,7 +4550,9 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
if (hub->has_indicators) {
hub->indicator[port1-1] =
INDICATOR_AMBER_BLINK;
- schedule_delayed_work (&hub->leds, 0);
+ queue_delayed_work(
+ system_power_efficient_wq,
+ &hub->leds, 0);
}
status = -ENOTCONN; /* Don't retry */
goto loop_disable;
--
1.7.9.5


2014-02-02 16:10:17

by Alan Stern

[permalink] [raw]
Subject: Re: [RFC PATCHv2] usb: move hub init and LED blink work to power efficient workqueue

On Sat, 1 Feb 2014, Zoran Markovic wrote:

> From: Shaibal Dutta <[email protected]>
>
> Allow the scheduler to select the best CPU to handle hub initalization
> and LED blinking work. This extends idle residency times on idle CPUs
> and conserves power.
>
> This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected.
>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Alan Stern <[email protected]>
> Cc: Sarah Sharp <[email protected]>
> Cc: Xenia Ragiadakou <[email protected]>
> Cc: Julius Werner <[email protected]>
> Cc: Krzysztof Mazur <[email protected]>
> Cc: Matthias Beyer <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Mathias Nyman <[email protected]>
> Cc: Thomas Pugliese <[email protected]>
> Signed-off-by: Shaibal Dutta <[email protected]>
> [[email protected]: Rebased to latest kernel. Added commit message.
> Changed reference from system to power efficient workqueue for LEDs in
> check_highspeed() and hub_port_connect_change().]
> Signed-off-by: Zoran Markovic <[email protected]>

Acked-off-by: Alan Stern <[email protected]>

Is there some reason why schedule_delayed_work() doesn't use the
power-efficient work queue by default?

Alan Stern

2014-02-07 12:03:53

by Zoran Markovic

[permalink] [raw]
Subject: Re: [RFC PATCHv2] usb: move hub init and LED blink work to power efficient workqueue

I believe there may still be use cases where you want to wake up the
same CPU that scheduled the work.

Thanks for the Ack. Can you please queue this for 3.14?

Regards, Zoran

On 2 February 2014 08:10, Alan Stern <[email protected]> wrote:
> On Sat, 1 Feb 2014, Zoran Markovic wrote:
>
>> From: Shaibal Dutta <[email protected]>
>>
>> Allow the scheduler to select the best CPU to handle hub initalization
>> and LED blinking work. This extends idle residency times on idle CPUs
>> and conserves power.
>>
>> This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected.
>>
>> Cc: Greg Kroah-Hartman <[email protected]>
>> Cc: Alan Stern <[email protected]>
>> Cc: Sarah Sharp <[email protected]>
>> Cc: Xenia Ragiadakou <[email protected]>
>> Cc: Julius Werner <[email protected]>
>> Cc: Krzysztof Mazur <[email protected]>
>> Cc: Matthias Beyer <[email protected]>
>> Cc: Dan Williams <[email protected]>
>> Cc: Mathias Nyman <[email protected]>
>> Cc: Thomas Pugliese <[email protected]>
>> Signed-off-by: Shaibal Dutta <[email protected]>
>> [[email protected]: Rebased to latest kernel. Added commit message.
>> Changed reference from system to power efficient workqueue for LEDs in
>> check_highspeed() and hub_port_connect_change().]
>> Signed-off-by: Zoran Markovic <[email protected]>
>
> Acked-off-by: Alan Stern <[email protected]>
>
> Is there some reason why schedule_delayed_work() doesn't use the
> power-efficient work queue by default?
>
> Alan Stern
>

2014-02-07 15:20:59

by Alan Stern

[permalink] [raw]
Subject: Re: [RFC PATCHv2] usb: move hub init and LED blink work to power efficient workqueue

Please don't top-post.

On Fri, 7 Feb 2014, Zoran Markovic wrote:

> I believe there may still be use cases where you want to wake up the
> same CPU that scheduled the work.

Won't the majority of cases not care which CPU is used? Therefore,
shouldn't the default behavior be to use the power-efficient work
queue?

> Thanks for the Ack. Can you please queue this for 3.14?

That's up to Greg KH. He may decide it's not important enough to go
into 3.14, and delay it until 3.15.

Alan Stern

2014-02-07 15:26:38

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [RFC PATCHv2] usb: move hub init and LED blink work to power efficient workqueue

On Fri, Feb 07, 2014 at 10:20:57AM -0500, Alan Stern wrote:
> Please don't top-post.
>
> On Fri, 7 Feb 2014, Zoran Markovic wrote:
>
> > I believe there may still be use cases where you want to wake up the
> > same CPU that scheduled the work.
>
> Won't the majority of cases not care which CPU is used? Therefore,
> shouldn't the default behavior be to use the power-efficient work
> queue?
>
> > Thanks for the Ack. Can you please queue this for 3.14?
>
> That's up to Greg KH. He may decide it's not important enough to go
> into 3.14, and delay it until 3.15.

It's 3.15 material, as it doesn't fix a regression at this point in
time.

I'll queue it up when I get to it in a week or so, thanks.

greg k-h