[3.11.y.z extended stable] Patch "sched: numa: skip inaccessible VMAs" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    sched: numa: skip inaccessible VMAs

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 5a1c854b89b85921ab87a9014218b495a42a8206 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman at suse.de>
Date: Tue, 7 Jan 2014 14:00:43 +0000
Subject: 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 at suse.de>
Reviewed-by: Rik van Riel <riel at redhat.com>
Cc: Alex Thorlton <athorlton at sgi.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 kernel/sched/fair.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 66dae75..a07a479 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);
--
1.8.3.2