Re: [PATCH V2] mm/hugetlb: remove unnecessary holding of hugetlb_lock

[Muchun Song <muchun.song@linux.dev>]

> On May 27, 2025, at 11:36, yangge1116@126.com wrote:
> 
> From: Ge Yang <yangge1116@126.com>
> 
> In the isolate_or_dissolve_huge_folio() function, after acquiring the
> hugetlb_lock, it is only for the purpose of obtaining the correct hstate,
> which is then passed to the alloc_and_dissolve_hugetlb_folio() function.
> 
> The alloc_and_dissolve_hugetlb_folio() function itself also acquires the
> hugetlb_lock. We can have the alloc_and_dissolve_hugetlb_folio() function
> obtain the hstate by itself, so that the isolate_or_dissolve_huge_folio()
> function no longer needs to acquire the hugetlb_lock. In addition, we keep
> the folio_test_hugetlb() check within the isolate_or_dissolve_huge_folio()
> function. By doing so, we can avoid disrupting the normal path by vainly
> holding the hugetlb_lock.
> 
> The replace_free_hugepage_folios() function has the same issue, and we
> should address it as well.
> 
> Suggested-by: Oscar Salvador <osalvador@suse.de>
> Signed-off-by: Ge Yang <yangge1116@126.com>

Reviewed-by: Muchun Song <muchun.song@linux.dev>

Thanks.