Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755477AbbGTO0r (ORCPT ); Mon, 20 Jul 2015 10:26:47 -0400 Received: from mga11.intel.com ([192.55.52.93]:45166 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932482AbbGTOVb (ORCPT ); Mon, 20 Jul 2015 10:21:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,508,1432623600"; d="scan'208";a="750785448" From: "Kirill A. Shutemov" To: Andrew Morton , Andrea Arcangeli , Hugh Dickins Cc: Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv9 33/36] migrate_pages: try to split pages on qeueuing Date: Mon, 20 Jul 2015 17:21:06 +0300 Message-Id: <1437402069-105900-34-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1437402069-105900-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1437402069-105900-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2228 Lines: 76 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: Kirill A. Shutemov Tested-by: Aneesh Kumar K.V --- mm/mempolicy.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b6122c0f613d..f815d7dfd4ad 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -489,14 +489,31 @@ 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; - split_huge_pmd(vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - return 0; + 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); + } 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; + } + } + } +retry: pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { if (!pte_present(*pte)) @@ -513,6 +530,18 @@ 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 - 1, ptl); + lock_page(page); + ret = split_huge_page(page); + unlock_page(page); + put_page(page); + /* Failed to split -- skip. */ + if (ret) + continue; + goto retry; + } if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) migrate_page_add(page, qp->pagelist, flags); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/