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Commit 248db92d authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
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migrate_pages: try to split pages on queuing 



We are not able to migrate THPs.  It means it's not enough to split only
PMD on migration -- we need to split compound page under it too.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: default avatarJerome Marchand <jmarchan@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e9b61f19

mm/mempolicy.c

+38 −4
Original line number Diff line number Diff line
@@ -489,14 +489,33 @@ 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 nid;

	int nid, ret;

	pte_t *pte;

	spinlock_t *ptl;



	if (pmd_trans_huge(*pmd)) {

		ptl = pmd_lock(walk->mm, pmd);

		if (pmd_trans_huge(*pmd)) {

			page = pmd_page(*pmd);

			if (is_huge_zero_page(page)) {

				spin_unlock(ptl);

				split_huge_pmd(vma, pmd, addr);

	if (pmd_trans_unstable(pmd))

			} else {

				get_page(page);

				spin_unlock(ptl);

				lock_page(page);

				ret = split_huge_page(page);

				unlock_page(page);

				put_page(page);

				if (ret)

					return 0;

			}

		} else {

			spin_unlock(ptl);

		}

	}



retry:

	pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);

	for (; addr != end; pte++, addr += PAGE_SIZE) {

		if (!pte_present(*pte))
@@ -513,6 +532,21 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, 
		nid = page_to_nid(page);

		if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))

			continue;

		if (PageTail(page) && PageAnon(page)) {

			get_page(page);

			pte_unmap_unlock(pte, ptl);

			lock_page(page);

			ret = split_huge_page(page);

			unlock_page(page);

			put_page(page);

			/* Failed to split -- skip. */

			if (ret) {

				pte = pte_offset_map_lock(walk->mm, pmd,

						addr, &ptl);

				continue;

			}

			goto retry;

		}



		if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))

			migrate_page_add(page, qp->pagelist, flags);