On Wed, 5 Jul 2023 05:39:31 +0800 Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> wrote:
> For PVMW_SYNC case, we always take pte lock when get first pte of
> PTE-mapped THP in map_pte and hold it until:
> 1. scan of pmd range finished or
> 2. scan of user input range finished or
> 3. user stop walk with page_vma_mapped_walk_done.
> In each case. pte lock will not be freed during middle scan of PTE-mapped
> THP.
>
> ...
>
> --- a/mm/page_vma_mapped.c
> +++ b/mm/page_vma_mapped.c
> @@ -275,10 +275,6 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
> goto restart;
> }
> pvmw->pte++;
> - if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) {
> - pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
> - spin_lock(pvmw->ptl);
> - }
> } while (pte_none(*pvmw->pte));
>
> if (!pvmw->ptl) {
This code has changed significantly since 6.4. Please develop against
the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm, thanks.
