Re: [PATCHv2 11/14] hugetlb: Remove VMEMMAP_SYNCHRONIZE_RCU

[Muchun Song]

> On Dec 18, 2025, at 23:09, Kiryl Shutsemau <kas@xxxxxxxxxx> wrote:
> 
> The VMEMMAP_SYNCHRONIZE_RCU flag triggered synchronize_rcu() calls to
> prevent a race between HVO remapping and page_ref_add_unless(). The
> race could occur when a speculative PFN walker tried to modify the
> refcount on a struct page that was in the process of being remapped
> to a fake head.
> 
> With fake heads eliminated, page_ref_add_unless() no longer needs RCU
> protection.
> 
> Remove the flag and synchronize_rcu() calls.
> 
> Signed-off-by: Kiryl Shutsemau <kas@xxxxxxxxxx>

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

Thanks.