mm/mempolicy: clean up the code logic in queue_pages_pte_range

Since commit e5947d23ed ("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: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Miaohe Lin 2022-04-28 23:16:06 -07:00 committed by akpm
parent da63dc84be
commit bc78b5ed9f

View File

@ -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;