mm: numa: do not automatically migrate KSM pages
KSM pages can be shared between tasks that are not necessarily related
to each other from a NUMA perspective. This patch causes those pages to
be ignored by automatic NUMA balancing so they do not migrate and do not
cause unrelated tasks to be grouped together.
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>
diff --git a/mm/mprotect.c b/mm/mprotect.c
index bb53a65..7332c17 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -23,6 +23,7 @@
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
#include <linux/perf_event.h>
+#include <linux/ksm.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
@@ -63,7 +64,7 @@
ptent = *pte;
page = vm_normal_page(vma, addr, oldpte);
- if (page) {
+ if (page && !PageKsm(page)) {
if (!pte_numa(oldpte)) {
ptent = pte_mknuma(ptent);
set_pte_at(mm, addr, pte, ptent);
