#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>
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
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.
/*
* 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();
}
/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct task_struct *tsk)
+static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup_taskset *tset)
{
- struct cpuset *cs = cgroup_cs(cont);
+ struct cpuset *cs = cgroup_cs(cgrp);
+ struct task_struct *task;
+ int ret;
if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
- /*
- * Kthreads bound to specific cpus cannot be moved to a new cpuset; we
- * cannot change their cpu affinity and isolating such threads by their
- * set of allowed nodes is unnecessary. Thus, cpusets are not
- * applicable for such threads. This prevents checking for success of
- * set_cpus_allowed_ptr() on all attached tasks before cpus_allowed may
- * be changed.
- */
- if (tsk->flags & PF_THREAD_BOUND)
- return -EINVAL;
-
+ cgroup_taskset_for_each(task, cgrp, tset) {
+ /*
+ * Kthreads bound to specific cpus cannot be moved to a new
+ * cpuset; we cannot change their cpu affinity and
+ * isolating such threads by their set of allowed nodes is
+ * unnecessary. Thus, cpusets are not applicable for such
+ * threads. This prevents checking for success of
+ * set_cpus_allowed_ptr() on all attached tasks before
+ * cpus_allowed may be changed.
+ */
+ if (task->flags & PF_THREAD_BOUND)
+ return -EINVAL;
+ if ((ret = security_task_setscheduler(task)))
+ return ret;
+ }
return 0;
}
-static int cpuset_can_attach_task(struct cgroup *cgrp, struct task_struct *task)
-{
- return security_task_setscheduler(task);
-}
-
/*
* Protected by cgroup_lock. The nodemasks must be stored globally because
* dynamically allocating them is not allowed in pre_attach, and they must
- * persist among pre_attach, attach_task, and attach.
+ * persist among pre_attach, and attach.
*/
static cpumask_var_t cpus_attach;
static nodemask_t cpuset_attach_nodemask_from;
guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
}
-/* Per-thread attachment work. */
-static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk)
+static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup_taskset *tset)
{
- int err;
- struct cpuset *cs = cgroup_cs(cont);
-
- /*
- * can_attach beforehand should guarantee that this doesn't fail.
- * TODO: have a better way to handle failure here
- */
- err = set_cpus_allowed_ptr(tsk, cpus_attach);
- WARN_ON_ONCE(err);
+ struct mm_struct *mm;
+ struct task_struct *task;
+ struct task_struct *leader = cgroup_taskset_first(tset);
+ struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
+ struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *oldcs = cgroup_cs(oldcgrp);
- cpuset_change_task_nodemask(tsk, &cpuset_attach_nodemask_to);
- cpuset_update_task_spread_flag(cs, tsk);
-}
+ cgroup_taskset_for_each(task, cgrp, tset) {
+ /*
+ * can_attach beforehand should guarantee that this doesn't
+ * fail. TODO: have a better way to handle failure here
+ */
+ WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach));
-static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct cgroup *oldcont, struct task_struct *tsk)
-{
- struct mm_struct *mm;
- struct cpuset *cs = cgroup_cs(cont);
- struct cpuset *oldcs = cgroup_cs(oldcont);
+ cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to);
+ cpuset_update_task_spread_flag(cs, task);
+ }
/*
* Change mm, possibly for multiple threads in a threadgroup. This is
*/
cpuset_attach_nodemask_from = oldcs->mems_allowed;
cpuset_attach_nodemask_to = cs->mems_allowed;
- mm = get_task_mm(tsk);
+ mm = get_task_mm(leader);
if (mm) {
mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
if (is_memory_migrate(cs))
.create = cpuset_create,
.destroy = cpuset_destroy,
.can_attach = cpuset_can_attach,
- .can_attach_task = cpuset_can_attach_task,
.pre_attach = cpuset_pre_attach,
- .attach_task = cpuset_attach_task,
.attach = cpuset_attach,
.populate = cpuset_populate,
.post_clone = cpuset_post_clone,
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff