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-rw-r--r--kernel/cpuset.c87
1 files changed, 46 insertions, 41 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f227bc17269..da7ff6137f3 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -36,6 +36,7 @@
#include <linux/list.h>
#include <linux/mempolicy.h>
#include <linux/mm.h>
+#include <linux/memory.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/namei.h>
@@ -587,7 +588,6 @@ static int generate_sched_domains(cpumask_t **domains,
int ndoms; /* number of sched domains in result */
int nslot; /* next empty doms[] cpumask_t slot */
- ndoms = 0;
doms = NULL;
dattr = NULL;
csa = NULL;
@@ -674,10 +674,8 @@ restart:
* Convert <csn, csa> to <ndoms, doms> and populate cpu masks.
*/
doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL);
- if (!doms) {
- ndoms = 0;
+ if (!doms)
goto done;
- }
/*
* The rest of the code, including the scheduler, can deal with
@@ -732,6 +730,13 @@ restart:
done:
kfree(csa);
+ /*
+ * Fallback to the default domain if kmalloc() failed.
+ * See comments in partition_sched_domains().
+ */
+ if (doms == NULL)
+ ndoms = 1;
+
*domains = doms;
*attributes = dattr;
return ndoms;
@@ -843,37 +848,25 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
/**
* update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
+ * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
*
* Called with cgroup_mutex held
*
* The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
* calling callback functions for each.
*
- * 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_cpumask(struct cpuset *cs)
+static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
{
struct cgroup_scanner scan;
- struct ptr_heap heap;
- int retval;
-
- /*
- * cgroup_scan_tasks() will initialize heap->gt for us.
- * heap_init() is still needed here for we should not change
- * cs->cpus_allowed when heap_init() fails.
- */
- retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
- if (retval)
- return retval;
scan.cg = cs->css.cgroup;
scan.test_task = cpuset_test_cpumask;
scan.process_task = cpuset_change_cpumask;
- scan.heap = &heap;
- retval = cgroup_scan_tasks(&scan);
-
- heap_free(&heap);
- return retval;
+ scan.heap = heap;
+ cgroup_scan_tasks(&scan);
}
/**
@@ -883,6 +876,7 @@ static int update_tasks_cpumask(struct cpuset *cs)
*/
static int update_cpumask(struct cpuset *cs, const char *buf)
{
+ struct ptr_heap heap;
struct cpuset trialcs;
int retval;
int is_load_balanced;
@@ -917,6 +911,10 @@ static int update_cpumask(struct cpuset *cs, const char *buf)
if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed))
return 0;
+ retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
+ if (retval)
+ return retval;
+
is_load_balanced = is_sched_load_balance(&trialcs);
mutex_lock(&callback_mutex);
@@ -927,9 +925,9 @@ static int update_cpumask(struct cpuset *cs, const char *buf)
* Scan tasks in the cpuset, and update the cpumasks of any
* that need an update.
*/
- retval = update_tasks_cpumask(cs);
- if (retval < 0)
- return retval;
+ update_tasks_cpumask(cs, &heap);
+
+ heap_free(&heap);
if (is_load_balanced)
async_rebuild_sched_domains();
@@ -1179,7 +1177,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
{
struct cpuset trialcs;
int err;
- int cpus_nonempty, balance_flag_changed;
+ int balance_flag_changed;
trialcs = *cs;
if (turning_on)
@@ -1191,7 +1189,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
if (err < 0)
return err;
- cpus_nonempty = !cpus_empty(trialcs.cpus_allowed);
balance_flag_changed = (is_sched_load_balance(cs) !=
is_sched_load_balance(&trialcs));
@@ -1199,7 +1196,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
cs->flags = trialcs.flags;
mutex_unlock(&callback_mutex);
- if (cpus_nonempty && balance_flag_changed)
+ if (!cpus_empty(trialcs.cpus_allowed) && balance_flag_changed)
async_rebuild_sched_domains();
return 0;
@@ -1928,7 +1925,7 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
* that has tasks along with an empty 'mems'. But if we did see such
* a cpuset, we'd handle it just like we do if its 'cpus' was empty.
*/
-static void scan_for_empty_cpusets(const struct cpuset *root)
+static void scan_for_empty_cpusets(struct cpuset *root)
{
LIST_HEAD(queue);
struct cpuset *cp; /* scans cpusets being updated */
@@ -1965,7 +1962,7 @@ static void scan_for_empty_cpusets(const struct cpuset *root)
nodes_empty(cp->mems_allowed))
remove_tasks_in_empty_cpuset(cp);
else {
- update_tasks_cpumask(cp);
+ update_tasks_cpumask(cp, NULL);
update_tasks_nodemask(cp, &oldmems);
}
}
@@ -2019,12 +2016,23 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
* Call this routine anytime after node_states[N_HIGH_MEMORY] changes.
* See also the previous routine cpuset_track_online_cpus().
*/
-void cpuset_track_online_nodes(void)
+static int cpuset_track_online_nodes(struct notifier_block *self,
+ unsigned long action, void *arg)
{
cgroup_lock();
- top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- scan_for_empty_cpusets(&top_cpuset);
+ switch (action) {
+ case MEM_ONLINE:
+ top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+ break;
+ case MEM_OFFLINE:
+ top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+ scan_for_empty_cpusets(&top_cpuset);
+ break;
+ default:
+ break;
+ }
cgroup_unlock();
+ return NOTIFY_OK;
}
#endif
@@ -2040,6 +2048,7 @@ void __init cpuset_init_smp(void)
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
hotcpu_notifier(cpuset_track_online_cpus, 0);
+ hotplug_memory_notifier(cpuset_track_online_nodes, 10);
}
/**
@@ -2444,19 +2453,15 @@ const struct file_operations proc_cpuset_operations = {
void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task)
{
seq_printf(m, "Cpus_allowed:\t");
- m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count,
- task->cpus_allowed);
+ seq_cpumask(m, &task->cpus_allowed);
seq_printf(m, "\n");
seq_printf(m, "Cpus_allowed_list:\t");
- m->count += cpulist_scnprintf(m->buf + m->count, m->size - m->count,
- task->cpus_allowed);
+ seq_cpumask_list(m, &task->cpus_allowed);
seq_printf(m, "\n");
seq_printf(m, "Mems_allowed:\t");
- m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count,
- task->mems_allowed);
+ seq_nodemask(m, &task->mems_allowed);
seq_printf(m, "\n");
seq_printf(m, "Mems_allowed_list:\t");
- m->count += nodelist_scnprintf(m->buf + m->count, m->size - m->count,
- task->mems_allowed);
+ seq_nodemask_list(m, &task->mems_allowed);
seq_printf(m, "\n");
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-04-13 05:25:52 +0000