aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-08-31 15:49:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-08-31 15:49:04 -0700
commit69dc8010b8fca475170650a4ebbc0074541df859 (patch)
tree780404347b60da432a098061c5ad1f654515d777
parent81b0b29bf70bb8b459cf1f0b4a6a4898be457850 (diff)
parentd20d30ebb199354729c64c86945ed25c66ff4991 (diff)
Merge branch 'for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "Two cpuset behavior changes: - cpuset on cgroup2 is changed to enable memory migration based on nodemask by default. - A notification is generated when cpuset partition state changes. All other patches are minor fixes and cleanups" * 'for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Avoid compiler warnings with no subsystems cgroup/cpuset: Avoid memory migration when nodemasks match cgroup/cpuset: Enable memory migration for cpuset v2 cgroup/cpuset: Enable event notification when partition state changes cgroup: cgroup-v1: clean up kernel-doc notation cgroup: Replace deprecated CPU-hotplug functions. cgroup/cpuset: Fix violation of cpuset locking rule cgroup/cpuset: Fix a partition bug with hotplug cgroup/cpuset: Miscellaneous code cleanup cgroup: remove cgroup_mount from comments
-rw-r--r--Documentation/admin-guide/cgroup-v2.rst11
-rw-r--r--kernel/cgroup/cgroup-v1.c8
-rw-r--r--kernel/cgroup/cgroup.c27
-rw-r--r--kernel/cgroup/cpuset.c162
4 files changed, 144 insertions, 64 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 5c7377b5bd3e..babbe04c8d37 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2056,6 +2056,17 @@ Cpuset Interface Files
The value of "cpuset.mems" stays constant until the next update
and won't be affected by any memory nodes hotplug events.
+ Setting a non-empty value to "cpuset.mems" causes memory of
+ tasks within the cgroup to be migrated to the designated nodes if
+ they are currently using memory outside of the designated nodes.
+
+ There is a cost for this memory migration. The migration
+ may not be complete and some memory pages may be left behind.
+ So it is recommended that "cpuset.mems" should be set properly
+ before spawning new tasks into the cpuset. Even if there is
+ a need to change "cpuset.mems" with active tasks, it shouldn't
+ be done frequently.
+
cpuset.mems.effective
A read-only multiple values file which exists on all
cpuset-enabled cgroups.
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index de2c432dee20..35b920328344 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -50,6 +50,8 @@ bool cgroup1_ssid_disabled(int ssid)
* cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from'
* @from: attach to all cgroups of a given task
* @tsk: the task to be attached
+ *
+ * Return: %0 on success or a negative errno code on failure
*/
int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
{
@@ -80,7 +82,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
/**
- * cgroup_trasnsfer_tasks - move tasks from one cgroup to another
+ * cgroup_transfer_tasks - move tasks from one cgroup to another
* @to: cgroup to which the tasks will be moved
* @from: cgroup in which the tasks currently reside
*
@@ -89,6 +91,8 @@ EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
* is guaranteed to be either visible in the source cgroup after the
* parent's migration is complete or put into the target cgroup. No task
* can slip out of migration through forking.
+ *
+ * Return: %0 on success or a negative errno code on failure
*/
int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
{
@@ -682,6 +686,8 @@ int proc_cgroupstats_show(struct seq_file *m, void *v)
*
* Build and fill cgroupstats so that taskstats can export it to user
* space.
+ *
+ * Return: %0 on success or a negative errno code on failure
*/
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
{
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 3a0161c21b6b..881ce1470beb 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -68,6 +68,14 @@
#define CGROUP_FILE_NOTIFY_MIN_INTV DIV_ROUND_UP(HZ, 100)
/*
+ * To avoid confusing the compiler (and generating warnings) with code
+ * that attempts to access what would be a 0-element array (i.e. sized
+ * to a potentially empty array when CGROUP_SUBSYS_COUNT == 0), this
+ * constant expression can be added.
+ */
+#define CGROUP_HAS_SUBSYS_CONFIG (CGROUP_SUBSYS_COUNT > 0)
+
+/*
* cgroup_mutex is the master lock. Any modification to cgroup or its
* hierarchy must be performed while holding it.
*
@@ -248,7 +256,7 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
*/
bool cgroup_ssid_enabled(int ssid)
{
- if (CGROUP_SUBSYS_COUNT == 0)
+ if (!CGROUP_HAS_SUBSYS_CONFIG)
return false;
return static_key_enabled(cgroup_subsys_enabled_key[ssid]);
@@ -472,7 +480,7 @@ static u16 cgroup_ss_mask(struct cgroup *cgrp)
static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp,
struct cgroup_subsys *ss)
{
- if (ss)
+ if (CGROUP_HAS_SUBSYS_CONFIG && ss)
return rcu_dereference_check(cgrp->subsys[ss->id],
lockdep_is_held(&cgroup_mutex));
else
@@ -550,6 +558,9 @@ struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp,
{
struct cgroup_subsys_state *css;
+ if (!CGROUP_HAS_SUBSYS_CONFIG)
+ return NULL;
+
do {
css = cgroup_css(cgrp, ss);
@@ -577,6 +588,9 @@ struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp,
{
struct cgroup_subsys_state *css;
+ if (!CGROUP_HAS_SUBSYS_CONFIG)
+ return NULL;
+
rcu_read_lock();
do {
@@ -647,7 +661,7 @@ struct cgroup_subsys_state *of_css(struct kernfs_open_file *of)
* the matching css from the cgroup's subsys table is guaranteed to
* be and stay valid until the enclosing operation is complete.
*/
- if (cft->ss)
+ if (CGROUP_HAS_SUBSYS_CONFIG && cft->ss)
return rcu_dereference_raw(cgrp->subsys[cft->ss->id]);
else
return &cgrp->self;
@@ -695,7 +709,7 @@ EXPORT_SYMBOL_GPL(of_css);
*/
#define do_each_subsys_mask(ss, ssid, ss_mask) do { \
unsigned long __ss_mask = (ss_mask); \
- if (!CGROUP_SUBSYS_COUNT) { /* to avoid spurious gcc warning */ \
+ if (!CGROUP_HAS_SUBSYS_CONFIG) { \
(ssid) = 0; \
break; \
} \
@@ -2169,7 +2183,6 @@ static void cgroup_kill_sb(struct super_block *sb)
/*
* If @root doesn't have any children, start killing it.
* This prevents new mounts by disabling percpu_ref_tryget_live().
- * cgroup_mount() may wait for @root's release.
*
* And don't kill the default root.
*/
@@ -2373,7 +2386,7 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
struct css_set *cset = tset->cur_cset;
struct task_struct *task = tset->cur_task;
- while (&cset->mg_node != tset->csets) {
+ while (CGROUP_HAS_SUBSYS_CONFIG && &cset->mg_node != tset->csets) {
if (!task)
task = list_first_entry(&cset->mg_tasks,
struct task_struct, cg_list);
@@ -4644,7 +4657,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
it->ss = css->ss;
it->flags = flags;
- if (it->ss)
+ if (CGROUP_HAS_SUBSYS_CONFIG && it->ss)
it->cset_pos = &css->cgroup->e_csets[css->ss->id];
else
it->cset_pos = &css->cgroup->cset_links;
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 6500cbe0ce16..df1ccf4558f8 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -160,6 +160,9 @@ struct cpuset {
*/
int use_parent_ecpus;
int child_ecpus_count;
+
+ /* Handle for cpuset.cpus.partition */
+ struct cgroup_file partition_file;
};
/*
@@ -263,6 +266,16 @@ static inline int is_partition_root(const struct cpuset *cs)
return cs->partition_root_state > 0;
}
+/*
+ * Send notification event of whenever partition_root_state changes.
+ */
+static inline void notify_partition_change(struct cpuset *cs,
+ int old_prs, int new_prs)
+{
+ if (old_prs != new_prs)
+ cgroup_file_notify(&cs->partition_file);
+}
+
static struct cpuset top_cpuset = {
.flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) |
(1 << CS_MEM_EXCLUSIVE)),
@@ -992,7 +1005,7 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
* 'cpus' is removed, then call this routine to rebuild the
* scheduler's dynamic sched domains.
*
- * Call with cpuset_mutex held. Takes get_online_cpus().
+ * Call with cpuset_mutex held. Takes cpus_read_lock().
*/
static void rebuild_sched_domains_locked(void)
{
@@ -1053,11 +1066,11 @@ static void rebuild_sched_domains_locked(void)
void rebuild_sched_domains(void)
{
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
rebuild_sched_domains_locked();
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
}
/**
@@ -1127,7 +1140,7 @@ enum subparts_cmd {
* cpus_allowed can be granted or an error code will be returned.
*
* For partcmd_disable, the cpuset is being transofrmed from a partition
- * root back to a non-partition root. any CPUs in cpus_allowed that are in
+ * root back to a non-partition root. Any CPUs in cpus_allowed that are in
* parent's subparts_cpus will be taken away from that cpumask and put back
* into parent's effective_cpus. 0 should always be returned.
*
@@ -1161,6 +1174,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
struct cpuset *parent = parent_cs(cpuset);
int adding; /* Moving cpus from effective_cpus to subparts_cpus */
int deleting; /* Moving cpus from subparts_cpus to effective_cpus */
+ int old_prs, new_prs;
bool part_error = false; /* Partition error? */
percpu_rwsem_assert_held(&cpuset_rwsem);
@@ -1196,6 +1210,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
* A cpumask update cannot make parent's effective_cpus become empty.
*/
adding = deleting = false;
+ old_prs = new_prs = cpuset->partition_root_state;
if (cmd == partcmd_enable) {
cpumask_copy(tmp->addmask, cpuset->cpus_allowed);
adding = true;
@@ -1238,7 +1253,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
/*
* partcmd_update w/o newmask:
*
- * addmask = cpus_allowed & parent->effectiveb_cpus
+ * addmask = cpus_allowed & parent->effective_cpus
*
* Note that parent's subparts_cpus may have been
* pre-shrunk in case there is a change in the cpu list.
@@ -1260,11 +1275,11 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
switch (cpuset->partition_root_state) {
case PRS_ENABLED:
if (part_error)
- cpuset->partition_root_state = PRS_ERROR;
+ new_prs = PRS_ERROR;
break;
case PRS_ERROR:
if (!part_error)
- cpuset->partition_root_state = PRS_ENABLED;
+ new_prs = PRS_ENABLED;
break;
}
/*
@@ -1273,10 +1288,10 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
part_error = (prev_prs == PRS_ERROR);
}
- if (!part_error && (cpuset->partition_root_state == PRS_ERROR))
+ if (!part_error && (new_prs == PRS_ERROR))
return 0; /* Nothing need to be done */
- if (cpuset->partition_root_state == PRS_ERROR) {
+ if (new_prs == PRS_ERROR) {
/*
* Remove all its cpus from parent's subparts_cpus.
*/
@@ -1285,7 +1300,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
parent->subparts_cpus);
}
- if (!adding && !deleting)
+ if (!adding && !deleting && (new_prs == old_prs))
return 0;
/*
@@ -1312,7 +1327,12 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
}
parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus);
+
+ if (old_prs != new_prs)
+ cpuset->partition_root_state = new_prs;
+
spin_unlock_irq(&callback_lock);
+ notify_partition_change(cpuset, old_prs, new_prs);
return cmd == partcmd_update;
}
@@ -1334,6 +1354,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
struct cpuset *cp;
struct cgroup_subsys_state *pos_css;
bool need_rebuild_sched_domains = false;
+ int old_prs, new_prs;
rcu_read_lock();
cpuset_for_each_descendant_pre(cp, pos_css, cs) {
@@ -1373,17 +1394,18 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
* update_tasks_cpumask() again for tasks in the parent
* cpuset if the parent's subparts_cpus changes.
*/
- if ((cp != cs) && cp->partition_root_state) {
+ old_prs = new_prs = cp->partition_root_state;
+ if ((cp != cs) && old_prs) {
switch (parent->partition_root_state) {
case PRS_DISABLED:
/*
* If parent is not a partition root or an
- * invalid partition root, clear the state
- * state and the CS_CPU_EXCLUSIVE flag.
+ * invalid partition root, clear its state
+ * and its CS_CPU_EXCLUSIVE flag.
*/
WARN_ON_ONCE(cp->partition_root_state
!= PRS_ERROR);
- cp->partition_root_state = 0;
+ new_prs = PRS_DISABLED;
/*
* clear_bit() is an atomic operation and
@@ -1404,11 +1426,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
/*
* When parent is invalid, it has to be too.
*/
- cp->partition_root_state = PRS_ERROR;
- if (cp->nr_subparts_cpus) {
- cp->nr_subparts_cpus = 0;
- cpumask_clear(cp->subparts_cpus);
- }
+ new_prs = PRS_ERROR;
break;
}
}
@@ -1420,8 +1438,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
spin_lock_irq(&callback_lock);
cpumask_copy(cp->effective_cpus, tmp->new_cpus);
- if (cp->nr_subparts_cpus &&
- (cp->partition_root_state != PRS_ENABLED)) {
+ if (cp->nr_subparts_cpus && (new_prs != PRS_ENABLED)) {
cp->nr_subparts_cpus = 0;
cpumask_clear(cp->subparts_cpus);
} else if (cp->nr_subparts_cpus) {
@@ -1448,7 +1465,12 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
= cpumask_weight(cp->subparts_cpus);
}
}
+
+ if (new_prs != old_prs)
+ cp->partition_root_state = new_prs;
+
spin_unlock_irq(&callback_lock);
+ notify_partition_change(cp, old_prs, new_prs);
WARN_ON(!is_in_v2_mode() &&
!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
@@ -1625,6 +1647,11 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
{
struct cpuset_migrate_mm_work *mwork;
+ if (nodes_equal(*from, *to)) {
+ mmput(mm);
+ return;
+ }
+
mwork = kzalloc(sizeof(*mwork), GFP_KERNEL);
if (mwork) {
mwork->mm = mm;
@@ -1950,34 +1977,32 @@ out:
/*
* update_prstate - update partititon_root_state
- * cs: the cpuset to update
- * val: 0 - disabled, 1 - enabled
+ * cs: the cpuset to update
+ * new_prs: new partition root state
*
* Call with cpuset_mutex held.
*/
-static int update_prstate(struct cpuset *cs, int val)
+static int update_prstate(struct cpuset *cs, int new_prs)
{
- int err;
+ int err, old_prs = cs->partition_root_state;
struct cpuset *parent = parent_cs(cs);
- struct tmpmasks tmp;
+ struct tmpmasks tmpmask;
- if ((val != 0) && (val != 1))
- return -EINVAL;
- if (val == cs->partition_root_state)
+ if (old_prs == new_prs)
return 0;
/*
* Cannot force a partial or invalid partition root to a full
* partition root.
*/
- if (val && cs->partition_root_state)
+ if (new_prs && (old_prs == PRS_ERROR))
return -EINVAL;
- if (alloc_cpumasks(NULL, &tmp))
+ if (alloc_cpumasks(NULL, &tmpmask))
return -ENOMEM;
err = -EINVAL;
- if (!cs->partition_root_state) {
+ if (!old_prs) {
/*
* Turning on partition root requires setting the
* CS_CPU_EXCLUSIVE bit implicitly as well and cpus_allowed
@@ -1991,31 +2016,27 @@ static int update_prstate(struct cpuset *cs, int val)
goto out;
err = update_parent_subparts_cpumask(cs, partcmd_enable,
- NULL, &tmp);
+ NULL, &tmpmask);
if (err) {
update_flag(CS_CPU_EXCLUSIVE, cs, 0);
goto out;
}
- cs->partition_root_state = PRS_ENABLED;
} else {
/*
* Turning off partition root will clear the
* CS_CPU_EXCLUSIVE bit.
*/
- if (cs->partition_root_state == PRS_ERROR) {
- cs->partition_root_state = 0;
+ if (old_prs == PRS_ERROR) {
update_flag(CS_CPU_EXCLUSIVE, cs, 0);
err = 0;
goto out;
}
err = update_parent_subparts_cpumask(cs, partcmd_disable,
- NULL, &tmp);
+ NULL, &tmpmask);
if (err)
goto out;
- cs->partition_root_state = 0;
-
/* Turning off CS_CPU_EXCLUSIVE will not return error */
update_flag(CS_CPU_EXCLUSIVE, cs, 0);
}
@@ -2028,11 +2049,18 @@ static int update_prstate(struct cpuset *cs, int val)
update_tasks_cpumask(parent);
if (parent->child_ecpus_count)
- update_sibling_cpumasks(parent, cs, &tmp);
+ update_sibling_cpumasks(parent, cs, &tmpmask);
rebuild_sched_domains_locked();
out:
- free_cpumasks(NULL, &tmp);
+ if (!err) {
+ spin_lock_irq(&callback_lock);
+ cs->partition_root_state = new_prs;
+ spin_unlock_irq(&callback_lock);
+ notify_partition_change(cs, old_prs, new_prs);
+ }
+
+ free_cpumasks(NULL, &tmpmask);
return err;
}
@@ -2293,7 +2321,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
cpuset_filetype_t type = cft->private;
int retval = 0;
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
if (!is_cpuset_online(cs)) {
retval = -ENODEV;
@@ -2331,7 +2359,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
}
out_unlock:
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
return retval;
}
@@ -2342,7 +2370,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
cpuset_filetype_t type = cft->private;
int retval = -ENODEV;
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
if (!is_cpuset_online(cs))
goto out_unlock;
@@ -2357,7 +2385,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
}
out_unlock:
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
return retval;
}
@@ -2396,7 +2424,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
kernfs_break_active_protection(of->kn);
flush_work(&cpuset_hotplug_work);
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
if (!is_cpuset_online(cs))
goto out_unlock;
@@ -2422,7 +2450,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
free_cpuset(trialcs);
out_unlock:
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
kernfs_unbreak_active_protection(of->kn);
css_put(&cs->css);
flush_workqueue(cpuset_migrate_mm_wq);
@@ -2553,7 +2581,7 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf,
return -EINVAL;
css_get(&cs->css);
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
if (!is_cpuset_online(cs))
goto out_unlock;
@@ -2561,7 +2589,7 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf,
retval = update_prstate(cs, val);
out_unlock:
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
css_put(&cs->css);
return retval ?: nbytes;
}
@@ -2713,6 +2741,7 @@ static struct cftype dfl_files[] = {
.write = sched_partition_write,
.private = FILE_PARTITION_ROOT,
.flags = CFTYPE_NOT_ON_ROOT,
+ .file_offset = offsetof(struct cpuset, partition_file),
},
{
@@ -2748,12 +2777,16 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
return ERR_PTR(-ENOMEM);
}
- set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
+ __set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
nodes_clear(cs->mems_allowed);
nodes_clear(cs->effective_mems);
fmeter_init(&cs->fmeter);
cs->relax_domain_level = -1;
+ /* Set CS_MEMORY_MIGRATE for default hierarchy */
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys))
+ __set_bit(CS_MEMORY_MIGRATE, &cs->flags);
+
return &cs->css;
}
@@ -2767,7 +2800,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
if (!parent)
return 0;
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
set_bit(CS_ONLINE, &cs->flags);
@@ -2820,7 +2853,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
spin_unlock_irq(&callback_lock);
out_unlock:
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
return 0;
}
@@ -2839,7 +2872,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
{
struct cpuset *cs = css_cs(css);
- get_online_cpus();
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
if (is_partition_root(cs))
@@ -2860,7 +2893,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
clear_bit(CS_ONLINE, &cs->flags);
percpu_up_write(&cpuset_rwsem);
- put_online_cpus();
+ cpus_read_unlock();
}
static void cpuset_css_free(struct cgroup_subsys_state *css)
@@ -3071,7 +3104,7 @@ retry:
goto retry;
}
- parent = parent_cs(cs);
+ parent = parent_cs(cs);
compute_effective_cpumask(&new_cpus, cs, parent);
nodes_and(new_mems, cs->mems_allowed, parent->effective_mems);
@@ -3093,8 +3126,10 @@ retry:
if (is_partition_root(cs) && (cpumask_empty(&new_cpus) ||
(parent->partition_root_state == PRS_ERROR))) {
if (cs->nr_subparts_cpus) {
+ spin_lock_irq(&callback_lock);
cs->nr_subparts_cpus = 0;
cpumask_clear(cs->subparts_cpus);
+ spin_unlock_irq(&callback_lock);
compute_effective_cpumask(&new_cpus, cs, parent);
}
@@ -3106,9 +3141,17 @@ retry:
*/
if ((parent->partition_root_state == PRS_ERROR) ||
cpumask_empty(&new_cpus)) {
+ int old_prs;
+
update_parent_subparts_cpumask(cs, partcmd_disable,
NULL, tmp);
- cs->partition_root_state = PRS_ERROR;
+ old_prs = cs->partition_root_state;
+ if (old_prs != PRS_ERROR) {
+ spin_lock_irq(&callback_lock);
+ cs->partition_root_state = PRS_ERROR;
+ spin_unlock_irq(&callback_lock);
+ notify_partition_change(cs, old_prs, PRS_ERROR);
+ }
}
cpuset_force_rebuild();
}
@@ -3179,6 +3222,13 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
cpus_updated = !cpumask_equal(top_cpuset.effective_cpus, &new_cpus);
mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems);
+ /*
+ * In the rare case that hotplug removes all the cpus in subparts_cpus,
+ * we assumed that cpus are updated.
+ */
+ if (!cpus_updated && top_cpuset.nr_subparts_cpus)
+ cpus_updated = true;
+
/* synchronize cpus_allowed to cpu_active_mask */
if (cpus_updated) {
spin_lock_irq(&callback_lock);

Privacy Policy