From: Mel Gorman <mgorman@suse.de>
Date: Tue, 7 Jan 2014 14:00:43 +0000 (+0000)
Subject: sched: numa: skip inaccessible VMAs
X-Git-Tag: v3.12.7~38
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cefeb27999f88f9348f1c55753339535ee9016aa;p=thirdparty%2Fkernel%2Fstable.git

sched: numa: skip inaccessible VMAs

commit 3c67f474558748b604e247d92b55dfe89654c81d upstream.

Inaccessible VMA should not be trapping NUMA hint faults. Skip them.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 513fc2fd51092..7765ad82736a7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -974,6 +974,13 @@ void task_numa_work(struct callback_head *work)
 		if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
 			continue;
 
+		/*
+		 * Skip inaccessible VMAs to avoid any confusion between
+		 * PROT_NONE and NUMA hinting ptes
+		 */
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+			continue;
+
 		do {
 			start = max(start, vma->vm_start);
 			end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);