Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc

[Randy Dunlap]

On 4/8/20 8:36 AM, Christoph Hellwig wrote:
> On Wed, Apr 08, 2020 at 08:15:19AM -0700, Matthew Wilcox wrote:
>>>>>  config ZSMALLOC_PGTABLE_MAPPING
>>>>>  	bool "Use page table mapping to access object in zsmalloc"
>>>>> -	depends on ZSMALLOC
>>>>> +	depends on ZSMALLOC=y
>>>>
>>>> It's a bool so this shouldn't matter... not needed.
>>>
>>> My mm/Kconfig has:
>>>
>>> config ZSMALLOC
>>> 	tristate "Memory allocator for compressed pages"
>>> 	depends on MMU
>>>
>>> which I think means it can be modular, no?
>>
>> Randy means that ZSMALLOC_PGTABLE_MAPPING is a bool, so I think hch's patch
>> is wrong ... if ZSMALLOC is 'm' then ZSMALLOC_PGTABLE_MAPPING would become
>> 'n' instead of 'y'.
> 
> In Linus' tree you can select PGTABLE_MAPPING=y with ZSMALLOC=m,
> and that fits my understanding of the kbuild language.  With this
> patch I can't anymore.
> 

Makes sense. thanks.

-- 
~Randy