return container_of(task_subsys_state(task, cpuset_subsys_id),
struct cpuset, css);
}
-struct cpuset_hotplug_scanner {
- struct cgroup_scanner scan;
- struct cgroup *to;
-};
/* bits in struct cpuset flags field */
typedef enum {
return 0;
}
+#ifdef CONFIG_SMP
/*
* Helper routine for generate_sched_domains().
* Do cpusets a, b have overlapping cpus_allowed masks?
put_online_cpus();
}
+#else /* !CONFIG_SMP */
+static void do_rebuild_sched_domains(struct work_struct *unused)
+{
+}
+
+static int generate_sched_domains(struct cpumask **domains,
+ struct sched_domain_attr **attributes)
+{
+ *domains = NULL;
+ return 1;
+}
+#endif /* CONFIG_SMP */
static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains);
mutex_unlock(&callback_mutex);
}
+/*
+ * Rebind task's vmas to cpuset's new mems_allowed, and migrate pages to new
+ * nodes if memory_migrate flag is set. Called with cgroup_mutex held.
+ */
+static void cpuset_change_nodemask(struct task_struct *p,
+ struct cgroup_scanner *scan)
+{
+ struct mm_struct *mm;
+ struct cpuset *cs;
+ int migrate;
+ const nodemask_t *oldmem = scan->data;
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return;
+
+ cs = cgroup_cs(scan->cg);
+ migrate = is_memory_migrate(cs);
+
+ mpol_rebind_mm(mm, &cs->mems_allowed);
+ if (migrate)
+ cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed);
+ mmput(mm);
+}
+
static void *cpuset_being_rebound;
/**
* update_tasks_nodemask - Update the nodemasks of tasks in the cpuset.
* @cs: the cpuset in which each task's mems_allowed mask needs to be changed
* @oldmem: old mems_allowed of cpuset cs
+ * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
*
* Called with cgroup_mutex held
- * Return 0 if successful, -errno if not.
+ * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * if @heap != NULL.
*/
-static int update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem)
+static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
+ struct ptr_heap *heap)
{
- struct task_struct *p;
- struct mm_struct **mmarray;
- int i, n, ntasks;
- int migrate;
- int fudge;
- struct cgroup_iter it;
- int retval;
+ struct cgroup_scanner scan;
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
- fudge = 10; /* spare mmarray[] slots */
- fudge += cpumask_weight(cs->cpus_allowed);/* imagine 1 fork-bomb/cpu */
- retval = -ENOMEM;
-
- /*
- * Allocate mmarray[] to hold mm reference for each task
- * in cpuset cs. Can't kmalloc GFP_KERNEL while holding
- * tasklist_lock. We could use GFP_ATOMIC, but with a
- * few more lines of code, we can retry until we get a big
- * enough mmarray[] w/o using GFP_ATOMIC.
- */
- while (1) {
- ntasks = cgroup_task_count(cs->css.cgroup); /* guess */
- ntasks += fudge;
- mmarray = kmalloc(ntasks * sizeof(*mmarray), GFP_KERNEL);
- if (!mmarray)
- goto done;
- read_lock(&tasklist_lock); /* block fork */
- if (cgroup_task_count(cs->css.cgroup) <= ntasks)
- break; /* got enough */
- read_unlock(&tasklist_lock); /* try again */
- kfree(mmarray);
- }
-
- n = 0;
-
- /* Load up mmarray[] with mm reference for each task in cpuset. */
- cgroup_iter_start(cs->css.cgroup, &it);
- while ((p = cgroup_iter_next(cs->css.cgroup, &it))) {
- struct mm_struct *mm;
-
- if (n >= ntasks) {
- printk(KERN_WARNING
- "Cpuset mempolicy rebind incomplete.\n");
- break;
- }
- mm = get_task_mm(p);
- if (!mm)
- continue;
- mmarray[n++] = mm;
- }
- cgroup_iter_end(cs->css.cgroup, &it);
- read_unlock(&tasklist_lock);
+ scan.cg = cs->css.cgroup;
+ scan.test_task = NULL;
+ scan.process_task = cpuset_change_nodemask;
+ scan.heap = heap;
+ scan.data = (nodemask_t *)oldmem;
/*
- * Now that we've dropped the tasklist spinlock, we can
- * rebind the vma mempolicies of each mm in mmarray[] to their
- * new cpuset, and release that mm. The mpol_rebind_mm()
- * call takes mmap_sem, which we couldn't take while holding
- * tasklist_lock. Forks can happen again now - the mpol_dup()
- * cpuset_being_rebound check will catch such forks, and rebind
- * their vma mempolicies too. Because we still hold the global
- * cgroup_mutex, we know that no other rebind effort will
- * be contending for the global variable cpuset_being_rebound.
+ * The mpol_rebind_mm() call takes mmap_sem, which we couldn't
+ * take while holding tasklist_lock. Forks can happen - the
+ * mpol_dup() cpuset_being_rebound check will catch such forks,
+ * and rebind their vma mempolicies too. Because we still hold
+ * the global cgroup_mutex, we know that no other rebind effort
+ * will be contending for the global variable cpuset_being_rebound.
* It's ok if we rebind the same mm twice; mpol_rebind_mm()
* is idempotent. Also migrate pages in each mm to new nodes.
*/
- migrate = is_memory_migrate(cs);
- for (i = 0; i < n; i++) {
- struct mm_struct *mm = mmarray[i];
-
- mpol_rebind_mm(mm, &cs->mems_allowed);
- if (migrate)
- cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed);
- mmput(mm);
- }
+ cgroup_scan_tasks(&scan);
/* We're done rebinding vmas to this cpuset's new mems_allowed. */
- kfree(mmarray);
cpuset_being_rebound = NULL;
- retval = 0;
-done:
- return retval;
}
/*
{
nodemask_t oldmem;
int retval;
+ struct ptr_heap heap;
/*
* top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
if (retval < 0)
goto done;
+ retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
+ if (retval < 0)
+ goto done;
+
mutex_lock(&callback_mutex);
cs->mems_allowed = trialcs->mems_allowed;
cs->mems_generation = cpuset_mems_generation++;
mutex_unlock(&callback_mutex);
- retval = update_tasks_nodemask(cs, &oldmem);
+ update_tasks_nodemask(cs, &oldmem, &heap);
+
+ heap_free(&heap);
done:
return retval;
}
static int update_relax_domain_level(struct cpuset *cs, s64 val)
{
+#ifdef CONFIG_SMP
if (val < -1 || val >= SD_LV_MAX)
return -EINVAL;
+#endif
if (val != cs->relax_domain_level) {
cs->relax_domain_level = val;
struct cgroup *cont, struct task_struct *tsk)
{
struct cpuset *cs = cgroup_cs(cont);
- int ret = 0;
if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
- if (tsk->flags & PF_THREAD_BOUND) {
- mutex_lock(&callback_mutex);
- if (!cpumask_equal(&tsk->cpus_allowed, cs->cpus_allowed))
- ret = -EINVAL;
- mutex_unlock(&callback_mutex);
- }
+ /*
+ * 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;
- return ret < 0 ? ret : security_task_setscheduler(tsk, 0, NULL);
+ return security_task_setscheduler(tsk, 0, NULL);
}
static void cpuset_attach(struct cgroup_subsys *ss,
.read_u64 = cpuset_read_u64,
.write_u64 = cpuset_write_u64,
.private = FILE_MEMORY_PRESSURE,
+ .mode = S_IRUGO,
},
{
static void cpuset_do_move_task(struct task_struct *tsk,
struct cgroup_scanner *scan)
{
- struct cpuset_hotplug_scanner *chsp;
+ struct cgroup *new_cgroup = scan->data;
- chsp = container_of(scan, struct cpuset_hotplug_scanner, scan);
- cgroup_attach_task(chsp->to, tsk);
+ cgroup_attach_task(new_cgroup, tsk);
}
/**
*/
static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
{
- struct cpuset_hotplug_scanner scan;
+ struct cgroup_scanner scan;
- scan.scan.cg = from->css.cgroup;
- scan.scan.test_task = NULL; /* select all tasks in cgroup */
- scan.scan.process_task = cpuset_do_move_task;
- scan.scan.heap = NULL;
- scan.to = to->css.cgroup;
+ scan.cg = from->css.cgroup;
+ scan.test_task = NULL; /* select all tasks in cgroup */
+ scan.process_task = cpuset_do_move_task;
+ scan.heap = NULL;
+ scan.data = to->css.cgroup;
- if (cgroup_scan_tasks(&scan.scan))
+ if (cgroup_scan_tasks(&scan))
printk(KERN_ERR "move_member_tasks_to_cpuset: "
"cgroup_scan_tasks failed\n");
}
remove_tasks_in_empty_cpuset(cp);
else {
update_tasks_cpumask(cp, NULL);
- update_tasks_nodemask(cp, &oldmems);
+ update_tasks_nodemask(cp, &oldmems, NULL);
}
}
}
}
cgroup_lock();
+ mutex_lock(&callback_mutex);
cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask);
+ mutex_unlock(&callback_mutex);
scan_for_empty_cpusets(&top_cpuset);
ndoms = generate_sched_domains(&doms, &attr);
cgroup_unlock();
cgroup_lock();
switch (action) {
case MEM_ONLINE:
- top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- break;
case MEM_OFFLINE:
+ mutex_lock(&callback_mutex);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- scan_for_empty_cpusets(&top_cpuset);
+ mutex_unlock(&callback_mutex);
+ if (action == MEM_OFFLINE)
+ scan_for_empty_cpusets(&top_cpuset);
break;
default:
break;
}
/**
- * cpuset_zone_allowed_softwall - Can we allocate on zone z's memory node?
- * @z: is this zone on an allowed node?
+ * cpuset_node_allowed_softwall - Can we allocate on a memory node?
+ * @node: is this an allowed node?
* @gfp_mask: memory allocation flags
*
- * If we're in interrupt, yes, we can always allocate. If
- * __GFP_THISNODE is set, yes, we can always allocate. If zone
- * z's node is in our tasks mems_allowed, yes. If it's not a
- * __GFP_HARDWALL request and this zone's nodes is in the nearest
- * hardwalled cpuset ancestor to this tasks cpuset, yes.
- * If the task has been OOM killed and has access to memory reserves
- * as specified by the TIF_MEMDIE flag, yes.
+ * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is
+ * set, yes, we can always allocate. If node is in our task's mems_allowed,
+ * yes. If it's not a __GFP_HARDWALL request and this node is in the nearest
+ * hardwalled cpuset ancestor to this task's cpuset, yes. If the task has been
+ * OOM killed and has access to memory reserves as specified by the TIF_MEMDIE
+ * flag, yes.
* Otherwise, no.
*
- * If __GFP_HARDWALL is set, cpuset_zone_allowed_softwall()
- * reduces to cpuset_zone_allowed_hardwall(). Otherwise,
- * cpuset_zone_allowed_softwall() might sleep, and might allow a zone
- * from an enclosing cpuset.
+ * If __GFP_HARDWALL is set, cpuset_node_allowed_softwall() reduces to
+ * cpuset_node_allowed_hardwall(). Otherwise, cpuset_node_allowed_softwall()
+ * might sleep, and might allow a node from an enclosing cpuset.
*
- * cpuset_zone_allowed_hardwall() only handles the simpler case of
- * hardwall cpusets, and never sleeps.
+ * cpuset_node_allowed_hardwall() only handles the simpler case of hardwall
+ * cpusets, and never sleeps.
*
* The __GFP_THISNODE placement logic is really handled elsewhere,
* by forcibly using a zonelist starting at a specified node, and by
* GFP_USER - only nodes in current tasks mems allowed ok.
*
* Rule:
- * Don't call cpuset_zone_allowed_softwall if you can't sleep, unless you
+ * Don't call cpuset_node_allowed_softwall if you can't sleep, unless you
* pass in the __GFP_HARDWALL flag set in gfp_flag, which disables
* the code that might scan up ancestor cpusets and sleep.
*/
-
-int __cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
+int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
{
- int node; /* node that zone z is on */
const struct cpuset *cs; /* current cpuset ancestors */
int allowed; /* is allocation in zone z allowed? */
if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
return 1;
- node = zone_to_nid(z);
might_sleep_if(!(gfp_mask & __GFP_HARDWALL));
if (node_isset(node, current->mems_allowed))
return 1;
}
/*
- * cpuset_zone_allowed_hardwall - Can we allocate on zone z's memory node?
- * @z: is this zone on an allowed node?
+ * cpuset_node_allowed_hardwall - Can we allocate on a memory node?
+ * @node: is this an allowed node?
* @gfp_mask: memory allocation flags
*
- * If we're in interrupt, yes, we can always allocate.
- * If __GFP_THISNODE is set, yes, we can always allocate. If zone
- * z's node is in our tasks mems_allowed, yes. If the task has been
- * OOM killed and has access to memory reserves as specified by the
- * TIF_MEMDIE flag, yes. Otherwise, no.
+ * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is
+ * set, yes, we can always allocate. If node is in our task's mems_allowed,
+ * yes. If the task has been OOM killed and has access to memory reserves as
+ * specified by the TIF_MEMDIE flag, yes.
+ * Otherwise, no.
*
* The __GFP_THISNODE placement logic is really handled elsewhere,
* by forcibly using a zonelist starting at a specified node, and by
* any node on the zonelist except the first. By the time any such
* calls get to this routine, we should just shut up and say 'yes'.
*
- * Unlike the cpuset_zone_allowed_softwall() variant, above,
- * this variant requires that the zone be in the current tasks
+ * Unlike the cpuset_node_allowed_softwall() variant, above,
+ * this variant requires that the node be in the current task's
* mems_allowed or that we're in interrupt. It does not scan up the
* cpuset hierarchy for the nearest enclosing mem_exclusive cpuset.
* It never sleeps.
*/
-
-int __cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
+int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
{
- int node; /* node that zone z is on */
-
if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
return 1;
- node = zone_to_nid(z);
if (node_isset(node, current->mems_allowed))
return 1;
/*
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff