lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 22 Mar 2013 16:23:51 -0400
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	linux-mm@...ck.org
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Mel Gorman <mel@....ul.ie>, Hugh Dickins <hughd@...gle.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Andi Kleen <andi@...stfloor.org>,
	Hillf Danton <dhillf@...il.com>, Michal Hocko <mhocko@...e.cz>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 06/10] migrate: add hugepage migration code to move_pages()

This patch extends move_pages() to handle vma with VM_HUGETLB set.
We will be able to migrate hugepage with move_pages(2) after
applying the enablement patch which comes later in this series.

We avoid getting refcount on tail pages of hugepage, because unlike thp,
hugepage is not split and we need not care about races with splitting.

And migration of larger (1GB for x86_64) hugepage are not enabled.

ChangeLog v2:
 - updated description and renamed patch title

Signed-off-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>
---
 mm/memory.c  |  6 ++++--
 mm/migrate.c | 26 +++++++++++++++++++-------
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git v3.9-rc3.orig/mm/memory.c v3.9-rc3/mm/memory.c
index 494526a..3b6ad3d 100644
--- v3.9-rc3.orig/mm/memory.c
+++ v3.9-rc3/mm/memory.c
@@ -1503,7 +1503,8 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
 	if (pud_none(*pud))
 		goto no_page_table;
 	if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) {
-		BUG_ON(flags & FOLL_GET);
+		if (flags & FOLL_GET)
+			goto out;
 		page = follow_huge_pud(mm, address, pud, flags & FOLL_WRITE);
 		goto out;
 	}
@@ -1514,8 +1515,9 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
 	if (pmd_none(*pmd))
 		goto no_page_table;
 	if (pmd_huge(*pmd) && vma->vm_flags & VM_HUGETLB) {
-		BUG_ON(flags & FOLL_GET);
 		page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
+		if (flags & FOLL_GET && PageHead(page))
+			get_page_foll(page);
 		goto out;
 	}
 	if ((flags & FOLL_NUMA) && pmd_numa(*pmd))
diff --git v3.9-rc3.orig/mm/migrate.c v3.9-rc3/mm/migrate.c
index 38912ae..ef8e4e3 100644
--- v3.9-rc3.orig/mm/migrate.c
+++ v3.9-rc3/mm/migrate.c
@@ -1104,7 +1104,11 @@ static struct page *new_page_node(struct page *p, unsigned long private,
 
 	*result = &pm->status;
 
-	return alloc_pages_exact_node(pm->node,
+	if (PageHuge(p))
+		return alloc_huge_page_node(page_hstate(compound_head(p)),
+					pm->node);
+	else
+		return alloc_pages_exact_node(pm->node,
 				GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
 }
 
@@ -1150,6 +1154,13 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
 		if (PageReserved(page))
 			goto put_and_set;
 
+		/*
+		 * follow_page(FOLL_GET) didn't get refcount for tail pages of
+		 * hugepage, so here we skip putting it.
+		 */
+		if (PageHuge(page) && PageTail(page))
+			goto set_status;
+
 		pp->page = page;
 		err = page_to_nid(page);
 
@@ -1164,6 +1175,12 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
 				!migrate_all)
 			goto put_and_set;
 
+		if (PageHuge(page)) {
+			get_page(page);
+			list_move_tail(&page->lru, &pagelist);
+			goto put_and_set;
+		}
+
 		err = isolate_lru_page(page);
 		if (!err) {
 			list_add_tail(&page->lru, &pagelist);
@@ -1181,13 +1198,8 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
 		pp->status = err;
 	}
 
-	err = 0;
-	if (!list_empty(&pagelist)) {
-		err = migrate_pages(&pagelist, new_page_node,
+	err = migrate_movable_pages(&pagelist, new_page_node,
 				(unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL);
-		if (err)
-			putback_lru_pages(&pagelist);
-	}
 
 	up_read(&mm->mmap_sem);
 	return err;
-- 
1.7.11.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists