Re: [PATCH] Remove CONFIG_PM altogether, enable power management all the time

[Frank Rowand <frank.rowand@gmail.com>]

On 02/09/11 09:07, Rafael J. Wysocki wrote:
> On Wednesday, February 09, 2011, Mark Brown wrote:
>> On Tue, Feb 08, 2011 at 03:35:29PM -0800, Frank Rowand wrote:
>>
>>> For 2.6.38-rc4, x86_64, CONFIG_NR_CPUS=4:
>>
>>> size vmlinux
>>>    text     data       bss       dec      hex  filename
>>>
>>> 6553910  3555020   9994240  20103170  132c002  vmlinux    with    CONFIG_PM
>>> 6512652  3553116   9994240  20060008  1321768  vmlinux    without CONFIG_PM
>>>
>>>   41258     1904         0     43162                      delta
>>
>>> That is big enough for me to care.
>>
>> Hrm, that's pretty surprising.  It'd be interesting to know how much of
>> that is due to the PM core itself and how much of that is from drivers.
>> For the drivers CONFIG_PM isn't really the option they should be using
>> in the first place - they mostly want some combination of PM_SLEEP and
>> PM_RUNTIME for the specific functionality.  I'm running some checks now.
>>
>>>  > CONFIG_PM_SLEEP=y
>>
>> Raphael's patch will make this a user visible option in place of raw
>> CONFIG_PM by default so you'd be able to turn that off.
> 
> No, it won't (just to clarify).

Raphael's patch will turn on CONFIG_PM in the correct circumstances, and
leave it off when not needed by other config options.  That means that
the size overhead will _not_ be an issue for me because CONFIG_PM
will not be enabled when not needed.

-Frank