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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org, dwg@au1.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH -V8 13/18] powerpc: Update gup_pmd_range to handle transparent hugepages
Date: Sun, 12 May 2013 21:44:20 +0530	[thread overview]
Message-ID: <1368375265-19593-14-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1368375265-19593-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/gup.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index 4b921af..3d36fd7 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -66,9 +66,20 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 		pmd_t pmd = *pmdp;
 
 		next = pmd_addr_end(addr, end);
-		if (pmd_none(pmd))
+		/*
+		 * The pmd_trans_splitting() check below explains why
+		 * pmdp_splitting_flush has to flush the tlb, to stop
+		 * this gup-fast code from running while we set the
+		 * splitting bit in the pmd. Returning zero will take
+		 * the slow path that will call wait_split_huge_page()
+		 * if the pmd is still in splitting state. gup-fast
+		 * can't because it has irq disabled and
+		 * wait_split_huge_page() would never return as the
+		 * tlb flush IPI wouldn't run.
+		 */
+		if (pmd_none(pmd) || pmd_trans_splitting(pmd))
 			return 0;
-		if (pmd_huge(pmd)) {
+		if (pmd_huge(pmd) || pmd_large(pmd)) {
 			if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
 					 write, pages, nr))
 				return 0;
-- 
1.8.1.2

  parent reply	other threads:[~2013-05-12 16:14 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-12 16:14 [PATCH -V8 00/18] THP support for PPC64 Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 01/18] powerpc/mm: Use the correct mask value when looking at pgtable address Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 02/18] mm/THP: Use pmd_populate to update the pmd with pgtable_t pointer Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 03/18] mm/THP: Use the right function when updating access flags Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 04/18] mm/THP: Add pmd args to pgtable deposit and withdraw APIs Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 05/18] mm/THP: withdraw the pgtable after pmdp related operations Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 06/18] mm/THP: Don't use HPAGE_SHIFT in transparent hugepage code Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 07/18] mm/THP: deposit the transpare huge pgtable before set_pmd Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 08/18] powerpc/THP: Double the PMD table size for THP Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 09/18] powerpc/THP: Implement transparent hugepages for ppc64 Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 10/18] powerpc: move find_linux_pte_or_hugepte and gup_hugepte to common code Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 11/18] powerpc: Update find_linux_pte_or_hugepte to handle transparent hugepages Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 12/18] powerpc: Replace find_linux_pte with find_linux_pte_or_hugepte Aneesh Kumar K.V
2013-05-12 16:14 ` Aneesh Kumar K.V [this message]
2013-05-12 16:14 ` [PATCH -V8 14/18] powerpc/THP: Add code to handle HPTE faults for hugepages Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 15/18] powerpc: Make linux pagetable walk safe with THP enabled Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 16/18] powerpc/THP: Enable THP on PPC64 Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 17/18] powerpc: Optimize hugepage invalidate Aneesh Kumar K.V
2013-05-12 16:14 ` [PATCH -V8 18/18] powerpc: disable assert_pte_locked for collapse_huge_page Aneesh Kumar K.V

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