Re: [PATCH 4/6] mm: don't remap unused subpages when splitting isolated thp

Usama Arif
2024-07-31T17:08:34Z

On 30/07/2024 19:07, Rik van Riel wrote:
> On Tue, 2024-07-30 at 13:46 +0100, Usama Arif wrote:
>>
>> + /*
>> + * The pmd entry mapping the old thp was flushed and the pte
>> mapping
>> + * this subpage has been non present. Therefore, this
>> subpage is
>> + * inaccessible. We don't need to remap it if it contains
>> only zeros.
>> + */
>> + addr = kmap_local_page(page);
>> + dirty = memchr_inv(addr, 0, PAGE_SIZE);
>> + kunmap_local(addr);
>> +
>> + if (dirty)
>> + return false;
>>
>
> A minor nitpick here. The word dirty has a few different meanings
> in memory management already.
>
> Could it be clearer to use something like "contains_data" ?
>

Thanks, yes makes much more sense, will use contains_data in the next revision.