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-rw-r--r--kernel/cpuset.c21
1 files changed, 16 insertions, 5 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9c9b7545c810..9fe58c46a426 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -37,7 +37,7 @@
#include <linux/mempolicy.h>
#include <linux/mm.h>
#include <linux/memory.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
@@ -55,7 +55,7 @@
#include <linux/sort.h>
#include <asm/uaccess.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/cgroup.h>
@@ -949,6 +949,8 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
static void cpuset_change_task_nodemask(struct task_struct *tsk,
nodemask_t *newmems)
{
+ bool masks_disjoint = !nodes_intersects(*newmems, tsk->mems_allowed);
+
repeat:
/*
* Allow tasks that have access to memory reserves because they have
@@ -963,7 +965,6 @@ repeat:
nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems);
mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1);
-
/*
* ensure checking ->mems_allowed_change_disable after setting all new
* allowed nodes.
@@ -980,9 +981,11 @@ repeat:
/*
* Allocation of memory is very fast, we needn't sleep when waiting
- * for the read-side.
+ * for the read-side. No wait is necessary, however, if at least one
+ * node remains unchanged.
*/
- while (ACCESS_ONCE(tsk->mems_allowed_change_disable)) {
+ while (masks_disjoint &&
+ ACCESS_ONCE(tsk->mems_allowed_change_disable)) {
task_unlock(tsk);
if (!task_curr(tsk))
yield();
@@ -2460,11 +2463,19 @@ static int cpuset_spread_node(int *rotor)
int cpuset_mem_spread_node(void)
{
+ if (current->cpuset_mem_spread_rotor == NUMA_NO_NODE)
+ current->cpuset_mem_spread_rotor =
+ node_random(&current->mems_allowed);
+
return cpuset_spread_node(&current->cpuset_mem_spread_rotor);
}
int cpuset_slab_spread_node(void)
{
+ if (current->cpuset_slab_spread_rotor == NUMA_NO_NODE)
+ current->cpuset_slab_spread_rotor =
+ node_random(&current->mems_allowed);
+
return cpuset_spread_node(&current->cpuset_slab_spread_rotor);
}