On Fri, Mar 26, 2021 at 11:08:00AM +1100, Alistair Popple wrote:
> +static bool try_to_munlock_one(struct page *page, struct vm_area_struct *vma,
> + unsigned long address, void *arg)
> +{
Is this function name right?
> + struct page_vma_mapped_walk pvmw = {
> + .page = page,
> + .vma = vma,
> + .address = address,
> + };
> +
> + /* munlock has nothing to gain from examining un-locked vmas */
> + if (!(vma->vm_flags & VM_LOCKED))
> + return true;
> +
> + while (page_vma_mapped_walk(&pvmw)) {
> + /* PTE-mapped THP are never mlocked */
> + if (!PageTransCompound(page)) {
> + /*
> + * Holding pte lock, we do *not* need
> + * mmap_lock here
> + */
> + mlock_vma_page(page);
Because the only action this function seems to take is to call
*mlock*_vma_page()
> + }
> + page_vma_mapped_walk_done(&pvmw);
> +
> + /* found a mlocked page, no point continuing munlock check */
> + return false;
> + }
> +
> + return true;
> +}
> +
> /**
> * try_to_munlock - try to munlock a page
> * @page: the page to be munlocked
> @@ -1796,8 +1821,7 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags)
> void try_to_munlock(struct page *page)
> {
But this is also called try_to_munlock ??
/**
* try_to_munlock - try to munlock a page
* @page: the page to be munlocked
*
* Called from munlock code. Checks all of the VMAs mapping the page
* to make sure nobody else has this page mlocked. The page will be
* returned with PG_mlocked cleared if no other vmas have it mlocked.
*/
So what clears PG_mlocked on this call path?
Something needs attention here..
Jason
