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

From: Randy Dunlap
Date: Wed Apr 08 2020 - 11:37:02 EST


On 4/8/20 8:15 AM, Matthew Wilcox wrote:
> On Wed, Apr 08, 2020 at 05:12:03PM +0200, Peter Zijlstra wrote:
>> On Wed, Apr 08, 2020 at 08:01:00AM -0700, Randy Dunlap wrote:
>>> Hi,
>>>
>>> On 4/8/20 4:59 AM, Christoph Hellwig wrote:
>>>> diff --git a/mm/Kconfig b/mm/Kconfig
>>>> index 36949a9425b8..614cc786b519 100644
>>>> --- a/mm/Kconfig
>>>> +++ b/mm/Kconfig
>>>> @@ -702,7 +702,7 @@ config ZSMALLOC
>>>>
>>>> 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?

ack. I misread it.

> 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'.

sigh, I wish that I had meant that. :)

thanks.

--
~Randy