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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org
Cc: linuxppc-dev@lists.ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH -V10 05/15] powerpc: Update find_linux_pte_or_hugepte to handle transparent hugepages
Date: Wed,  5 Jun 2013 20:58:29 +0530	[thread overview]
Message-ID: <1370446119-8837-6-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1370446119-8837-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

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

Reviewed-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/hugetlbpage.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 2865077..4928204 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -936,30 +936,50 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
 
 	pg = pgdir + pgd_index(ea);
 
-	if (pgd_huge(*pg)) {
+	/*
+	 * we should first check for none. That takes care of a
+	 * a parallel hugetlb or THP pagefault moving none entries
+	 * to respective types.
+	 */
+	if (pgd_none(*pg))
+		return NULL;
+	else if (pgd_huge(*pg)) {
 		ret_pte = (pte_t *) pg;
 		goto out;
 	} else if (is_hugepd(pg))
 		hpdp = (hugepd_t *)pg;
-	else if (!pgd_none(*pg)) {
+	else {
 		pdshift = PUD_SHIFT;
 		pu = pud_offset(pg, ea);
 
-		if (pud_huge(*pu)) {
+		if (pud_none(*pu))
+			return NULL;
+		else if (pud_huge(*pu)) {
 			ret_pte = (pte_t *) pu;
 			goto out;
 		} else if (is_hugepd(pu))
 			hpdp = (hugepd_t *)pu;
-		else if (!pud_none(*pu)) {
+		else {
 			pdshift = PMD_SHIFT;
 			pm = pmd_offset(pu, ea);
+			/*
+			 * A hugepage collapse is captured by pmd_none, because
+			 * it mark the pmd none and do a hpte invalidate.
+			 *
+			 * A hugepage split is captured by pmd_trans_splitting
+			 * because we mark the pmd trans splitting and do a
+			 * hpte invalidate
+			 *
+			 */
+			if (pmd_none(*pm) || pmd_trans_splitting(*pm))
+				return NULL;
 
-			if (pmd_huge(*pm)) {
+			if (pmd_huge(*pm) || pmd_large(*pm)) {
 				ret_pte = (pte_t *) pm;
 				goto out;
 			} else if (is_hugepd(pm))
 				hpdp = (hugepd_t *)pm;
-			else if (!pmd_none(*pm))
+			else
 				return pte_offset_kernel(pm, ea);
 		}
 	}
-- 
1.8.1.2

  parent reply	other threads:[~2013-06-05 15:28 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-05 15:28 [PATCH -V10 00/15] THP support for PPC64 Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 01/15] powerpc/mm: handle hugepage size correctly when invalidating hpte entries Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 02/15] powerpc/THP: Double the PMD table size for THP Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 03/15] powerpc/THP: Implement transparent hugepages for ppc64 Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 04/15] powerpc: move find_linux_pte_or_hugepte and gup_hugepte to common code Aneesh Kumar K.V
2013-06-05 15:28 ` Aneesh Kumar K.V [this message]
2013-06-05 15:28 ` [PATCH -V10 06/15] powerpc: Replace find_linux_pte with find_linux_pte_or_hugepte Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 07/15] powerpc: Update gup_pmd_range to handle transparent hugepages Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 08/15] powerpc/THP: Add code to handle HPTE faults for hugepages Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 09/15] powerpc: Make linux pagetable walk safe with THP enabled Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 10/15] powerpc: Prevent gcc to re-read the pagetables Aneesh Kumar K.V
2013-06-05 15:41   ` David Laight
2013-06-05 22:39     ` Benjamin Herrenschmidt
2013-06-05 15:28 ` [PATCH -V10 11/15] powerpc/THP: Enable THP on PPC64 Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 12/15] powerpc: Optimize hugepage invalidate Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 13/15] powerpc: disable assert_pte_locked for collapse_huge_page Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 14/15] powerpc: use smp_rmb when looking at deposisted pgtable to store hash index Aneesh Kumar K.V
2013-06-05 15:28 ` [PATCH -V10 15/15] powerpc: split hugepage when using subpage protection Aneesh Kumar K.V
2013-06-05 23:31 ` [PATCH -V10 00/15] THP support for PPC64 Benjamin Herrenschmidt
2013-06-06  0:13   ` Andrew Morton
2013-06-06  6:05     ` Aneesh Kumar K.V
2013-06-06  7:20       ` Andrew Morton
2013-06-16  2:00 ` Benjamin Herrenschmidt
2013-06-16  3:37   ` Benjamin Herrenschmidt
2013-06-16  4:06     ` Benjamin Herrenschmidt
2013-06-16 23:02       ` Benjamin Herrenschmidt
2013-06-18 18:46       ` Aneesh Kumar K.V
2013-06-18 22:03         ` Benjamin Herrenschmidt
2013-06-19  3:30           ` Aneesh Kumar K.V
2013-06-18 17:54   ` Aneesh Kumar K.V

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