[PATCH v4] mm,kfence: decouple kfence from page granularity mapping judgement

[Zhenhua Huang]

Thanks Andrew!

On 2023/3/13 5:01, Andrew Morton wrote:
> On Fri, 10 Mar 2023 17:30:04 +0800 Zhenhua Huang <quic_zhenhuah at quicinc.com> wrote:
> 
>> Kfence only needs its pool to be mapped as page granularity, previous
>> judgement was a bit over protected. Decouple it from judgement and do
>> page granularity mapping for kfence pool only [1].
>>
>> To implement this, also relocate the kfence pool allocation before the
>> linear mapping setting up, arm64_kfence_alloc_pool is to allocate phys
>> addr, __kfence_pool is to be set after linear mapping set up.
> 
> Why make this change?  What are the benefits?  What are the user
> visible effects?
> 
>> LINK: [1] https://lore.kernel.org/linux-arm-kernel/1675750519-1064-1-git-send-email-quic_zhenhuah@quicinc.com/T/
> 
> Chasing the links indicates that "page-granular mapping costed more (2M
> per 1GB) memory".  Please spell all this out in this patch's changelog.

Yeah, let me update these and also my test outcome in changelog to make 
it clear~! Thanks.

> 
> btw. this format:
> 
> Link: https://lore.kernel.org/linux-arm-kernel/1675750519-1064-1-git-send-email-quic_zhenhuah@quicinc.com/T/ [1]
> 
> is conventional.

Do you mean it was not directly pointing to Mark's suggestion? let me 
update to: 
https://lore.kernel.org/linux-arm-kernel/Y+IsdrvDNILA59UN@FVFF77S0Q05N/

>