[Devel] [PATCH RHEL7] Removed warning from kmalloc in function alloc_rootdomain

[Valeriy Vdovin]

'alloc_rootdomain' is used during cpu hotplug actions when cpu's are
removed or added. So it's relatively rare occasion. The size of
allocated structure 'struct root_domain' is ~22k, which is a warnable
order 3. Because this structure is related to sched domain the code
accessing it is considered of high priority due to execution in
scheduling codepaths, so we should not fallback to virtualized page
continuity in this allocation and suppress order warning instead.

Signed-off-by: Valeriy Vdovin <valeriy.vdovin at virtuozzo.com>
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3fe0d62..8d14614 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7141,7 +7141,7 @@ static struct root_domain *alloc_rootdomain(void)
 {
 	struct root_domain *rd;
 
-	rd = kmalloc(sizeof(*rd), GFP_KERNEL);
+	rd = kmalloc(sizeof(*rd), GFP_KERNEL | __GFP_ORDER_NOWARN);
 	if (!rd)
 		return NULL;
 
-- 
1.8.3.1