diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 10131fdaff70..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> @@ -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(); |