Re: [PATCH] mm/memcg: remove definition of MEM_CGROUP_ID_MAX when !CONFIG_MEMCG

[Muchun Song <muchun.song-fxUVXftIFDnyG1zEObXtfA@public.gmane.org>]

> On Jul 7, 2023, at 10:06, Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> wrote:
> 
> On 2023/7/7 9:47, Muchun Song wrote:
>> 
>> 
>>> On Jul 6, 2023, at 19:28, Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> wrote:
>>> 
>>> MEM_CGROUP_ID_MAX is only used when CONFIG_MEMCG is configured. Remove
>>> unneeded !CONFIG_MEMCG variant.
>>> 
>>> Signed-off-by: Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
>> 
>> MEM_CGROUP_ID_MAX is also only used in mem_cgroup_alloc(), maybe you also
>> could move it from memcontrol.h to memcontrol.c. And define it as:
>> 
>> #define MEM_CGROUP_ID_MAX ((1U << MEM_CGROUP_ID_SHIFT) - 1)
>> 
>> I am not suggesting defining it as USHRT_MAX, because if someone changes
>> MEM_CGROUP_ID_SHIFT in the future, then MEM_CGROUP_ID_MAX will not updated
>> accordingly.
> 
> Looks sensible to me. Do you suggest squashing above changes into the current patch
> or a separate patch is preferred?

I think it's better to squash.

> 
>> 
>> For this patch, LGTM.
>> 
>> Reviewed-by: Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>
> 
> Thanks for review and suggestion.
> 
> 
>