Commit bc78b5ed authored by Miaohe Lin's avatar Miaohe Lin Committed by Andrew Morton
Browse files

mm/mempolicy: clean up the code logic in queue_pages_pte_range 

Since commit e5947d23 ("mm: mempolicy: don't have to split pmd for
huge zero page"), THP is never splited in queue_pages_pmd.  Thus 2 is
never returned now.  We can remove such unnecessary ret != 2 check and
clean up the relevant comment.  Minor improvements in readability.

Link: https://lkml.kernel.org/r/20220419122234.45083-1-linmiaohe@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent da63dc84

mm/mempolicy.c

+3 −9
Original line number Diff line number Diff line
@@ -440,12 +440,11 @@ static inline bool queue_pages_required(struct page *page, 
}



/*

 * queue_pages_pmd() has four possible return values:

 * queue_pages_pmd() has three possible return values:

 * 0 - pages are placed on the right node or queued successfully, or

 *     special page is met, i.e. huge zero page.

 * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were

 *     specified.

 * 2 - THP was split.

 * -EIO - is migration entry or only MPOL_MF_STRICT was specified and an

 *        existing page was already on a node that does not follow the

 *        policy.
@@ -507,18 +506,13 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, 
	struct page *page;

	struct queue_pages *qp = walk->private;

	unsigned long flags = qp->flags;

	int ret;

	bool has_unmovable = false;

	pte_t *pte, *mapped_pte;

	spinlock_t *ptl;



	ptl = pmd_trans_huge_lock(pmd, vma);

	if (ptl) {

		ret = queue_pages_pmd(pmd, ptl, addr, end, walk);

		if (ret != 2)

			return ret;

	}

	/* THP was split, fall through to pte walk */

	if (ptl)

		return queue_pages_pmd(pmd, ptl, addr, end, walk);



	if (pmd_trans_unstable(pmd))

		return 0;