Am 19.11.2012 21:06, schrieb Kerin Millar:
> Florian Philipp wrote:
>> Am 19.11.2012 18:51, schrieb Kerin Millar:
>>> Florian Philipp wrote:
>>>> Hi list!
>>>>
>>>> I'm wondering about the usage of frontswap and cleancache. Now that all
>>>> pieces are in place in kernel-3.5, is it actually used?
>>>>
>>>> I've found references to cleancache and frontswap in several source
>>>> files of the kernel (ext4, swapfile, page_io, ...).
>>>> /sys/kernel/mm/zcache is also present but seems to indicate no usage at
>>>> all. Content attached below.
>>> It might be that you have enabled some of these options as loadable
>>> modules: CONFIG_ZCACHE, CONFIG_CLEANCACHE and CONFIG_FRONTSWAP. If so,
>>> build them directly into the kernel image instead.
>>>
>>> Cheers,
>>>
>>> --Kerin
>>>
>>
>> You cannot build these as modules. Anyway, I'm recompiling right now
>> with debugfs and configfs. Let's see if that tells me anything.
>>
>> Regards,
>> Florian Philipp
>>
> 
> Ah, good to know. I know that it was possible in some older kernels -
> while the feature was still in staging - but it must have since been fixed.
> 
> --Kerin
> 

Okay, fixed my issue. Turns out, you need to add a "zcache" kernel
parameter. Too bad there is no doc on this parameter.

Regards,
Florian Philipp