On 2024/4/23 09:17, Barry Song wrote:
[...]
>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>> index 26b6fa98d8ac..67b9c1acad31 100644
>> --- a/include/linux/huge_mm.h
>> +++ b/include/linux/huge_mm.h
>> @@ -270,6 +270,8 @@ enum mthp_stat_item {
>> MTHP_STAT_ANON_SWPOUT,
>> MTHP_STAT_ANON_SWPOUT_FALLBACK,
>> MTHP_STAT_ANON_SWPIN_REFAULT,
>> + MTHP_STAT_SHMEM_ANON_ALLOC,
>> + MTHP_STAT_SHMEM_ANON_ALLOC_FALLBACK,
>
> not quite sure about this. for 2MB pmd-mapped THP shmem, we count them
> as FILE_THP.
> here we are counting as SHMEM_ANON. To me, SHMEM_ANON is more correct but
> it doesn't align with pmd-mapped THP. David, Ryan, what do you think?
+1
IMO, shmem isn't actually file-backed, but it has file-backed-like
characteristics :)
FWIW, perhaps MTHP_STAT_FILE_ALLOC and MTHP_STAT_FILE_ALLOC_FALLBACK
would better align with PMD/PTE-mapped THP.
Thanks,
Lance
