Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup update from Tejun Heo:
"cpuset got simplified a bit. cgroup core got a fix on unified
hierarchy and grew some effective css related interfaces which will be
used for blkio support for writeback IO traffic which is currently
being worked on"
* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: implement cgroup_get_e_css()
cgroup: add cgroup_subsys->css_e_css_changed()
cgroup: add cgroup_subsys->css_released()
cgroup: fix the async css offline wait logic in cgroup_subtree_control_write()
cgroup: restructure child_subsys_mask handling in cgroup_subtree_control_write()
cgroup: separate out cgroup_calc_child_subsys_mask() from cgroup_refresh_child_subsys_mask()
cpuset: lock vs unlock typo
cpuset: simplify cpuset_node_allowed API
cpuset: convert callback_mutex to a spinlock
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 641e564..da0dae0 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -638,8 +638,10 @@
struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
int (*css_online)(struct cgroup_subsys_state *css);
void (*css_offline)(struct cgroup_subsys_state *css);
+ void (*css_released)(struct cgroup_subsys_state *css);
void (*css_free)(struct cgroup_subsys_state *css);
void (*css_reset)(struct cgroup_subsys_state *css);
+ void (*css_e_css_changed)(struct cgroup_subsys_state *css);
int (*can_attach)(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset);
@@ -934,6 +936,8 @@
int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
+struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
+ struct cgroup_subsys *ss);
struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
struct cgroup_subsys *ss);
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 2f073db..1b35799 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -48,29 +48,16 @@
void cpuset_init_current_mems_allowed(void);
int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
-extern int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask);
-extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);
+extern int __cpuset_node_allowed(int node, gfp_t gfp_mask);
-static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
+static inline int cpuset_node_allowed(int node, gfp_t gfp_mask)
{
- return nr_cpusets() <= 1 ||
- __cpuset_node_allowed_softwall(node, gfp_mask);
+ return nr_cpusets() <= 1 || __cpuset_node_allowed(node, gfp_mask);
}
-static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
+static inline int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
{
- return nr_cpusets() <= 1 ||
- __cpuset_node_allowed_hardwall(node, gfp_mask);
-}
-
-static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
-{
- return cpuset_node_allowed_softwall(zone_to_nid(z), gfp_mask);
-}
-
-static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
-{
- return cpuset_node_allowed_hardwall(zone_to_nid(z), gfp_mask);
+ return cpuset_node_allowed(zone_to_nid(z), gfp_mask);
}
extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
@@ -179,22 +166,12 @@
return 1;
}
-static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
+static inline int cpuset_node_allowed(int node, gfp_t gfp_mask)
{
return 1;
}
-static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
-{
- return 1;
-}
-
-static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
-{
- return 1;
-}
-
-static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
+static inline int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
{
return 1;
}
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 136ecead..bb263d0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -277,6 +277,10 @@
if (!(cgrp->root->subsys_mask & (1 << ss->id)))
return NULL;
+ /*
+ * This function is used while updating css associations and thus
+ * can't test the csses directly. Use ->child_subsys_mask.
+ */
while (cgroup_parent(cgrp) &&
!(cgroup_parent(cgrp)->child_subsys_mask & (1 << ss->id)))
cgrp = cgroup_parent(cgrp);
@@ -284,6 +288,39 @@
return cgroup_css(cgrp, ss);
}
+/**
+ * cgroup_get_e_css - get a cgroup's effective css for the specified subsystem
+ * @cgrp: the cgroup of interest
+ * @ss: the subsystem of interest
+ *
+ * Find and get the effective css of @cgrp for @ss. The effective css is
+ * defined as the matching css of the nearest ancestor including self which
+ * has @ss enabled. If @ss is not mounted on the hierarchy @cgrp is on,
+ * the root css is returned, so this function always returns a valid css.
+ * The returned css must be put using css_put().
+ */
+struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp,
+ struct cgroup_subsys *ss)
+{
+ struct cgroup_subsys_state *css;
+
+ rcu_read_lock();
+
+ do {
+ css = cgroup_css(cgrp, ss);
+
+ if (css && css_tryget_online(css))
+ goto out_unlock;
+ cgrp = cgroup_parent(cgrp);
+ } while (cgrp);
+
+ css = init_css_set.subsys[ss->id];
+ css_get(css);
+out_unlock:
+ rcu_read_unlock();
+ return css;
+}
+
/* convenient tests for these bits */
static inline bool cgroup_is_dead(const struct cgroup *cgrp)
{
@@ -1019,31 +1056,30 @@
}
/**
- * cgroup_refresh_child_subsys_mask - update child_subsys_mask
+ * cgroup_calc_child_subsys_mask - calculate child_subsys_mask
* @cgrp: the target cgroup
+ * @subtree_control: the new subtree_control mask to consider
*
* On the default hierarchy, a subsystem may request other subsystems to be
* enabled together through its ->depends_on mask. In such cases, more
* subsystems than specified in "cgroup.subtree_control" may be enabled.
*
- * This function determines which subsystems need to be enabled given the
- * current @cgrp->subtree_control and records it in
- * @cgrp->child_subsys_mask. The resulting mask is always a superset of
- * @cgrp->subtree_control and follows the usual hierarchy rules.
+ * This function calculates which subsystems need to be enabled if
+ * @subtree_control is to be applied to @cgrp. The returned mask is always
+ * a superset of @subtree_control and follows the usual hierarchy rules.
*/
-static void cgroup_refresh_child_subsys_mask(struct cgroup *cgrp)
+static unsigned int cgroup_calc_child_subsys_mask(struct cgroup *cgrp,
+ unsigned int subtree_control)
{
struct cgroup *parent = cgroup_parent(cgrp);
- unsigned int cur_ss_mask = cgrp->subtree_control;
+ unsigned int cur_ss_mask = subtree_control;
struct cgroup_subsys *ss;
int ssid;
lockdep_assert_held(&cgroup_mutex);
- if (!cgroup_on_dfl(cgrp)) {
- cgrp->child_subsys_mask = cur_ss_mask;
- return;
- }
+ if (!cgroup_on_dfl(cgrp))
+ return cur_ss_mask;
while (true) {
unsigned int new_ss_mask = cur_ss_mask;
@@ -1067,7 +1103,20 @@
cur_ss_mask = new_ss_mask;
}
- cgrp->child_subsys_mask = cur_ss_mask;
+ return cur_ss_mask;
+}
+
+/**
+ * cgroup_refresh_child_subsys_mask - update child_subsys_mask
+ * @cgrp: the target cgroup
+ *
+ * Update @cgrp->child_subsys_mask according to the current
+ * @cgrp->subtree_control using cgroup_calc_child_subsys_mask().
+ */
+static void cgroup_refresh_child_subsys_mask(struct cgroup *cgrp)
+{
+ cgrp->child_subsys_mask =
+ cgroup_calc_child_subsys_mask(cgrp, cgrp->subtree_control);
}
/**
@@ -2641,7 +2690,7 @@
loff_t off)
{
unsigned int enable = 0, disable = 0;
- unsigned int css_enable, css_disable, old_ctrl, new_ctrl;
+ unsigned int css_enable, css_disable, old_sc, new_sc, old_ss, new_ss;
struct cgroup *cgrp, *child;
struct cgroup_subsys *ss;
char *tok;
@@ -2693,36 +2742,6 @@
ret = -ENOENT;
goto out_unlock;
}
-
- /*
- * @ss is already enabled through dependency and
- * we'll just make it visible. Skip draining.
- */
- if (cgrp->child_subsys_mask & (1 << ssid))
- continue;
-
- /*
- * Because css offlining is asynchronous, userland
- * might try to re-enable the same controller while
- * the previous instance is still around. In such
- * cases, wait till it's gone using offline_waitq.
- */
- cgroup_for_each_live_child(child, cgrp) {
- DEFINE_WAIT(wait);
-
- if (!cgroup_css(child, ss))
- continue;
-
- cgroup_get(child);
- prepare_to_wait(&child->offline_waitq, &wait,
- TASK_UNINTERRUPTIBLE);
- cgroup_kn_unlock(of->kn);
- schedule();
- finish_wait(&child->offline_waitq, &wait);
- cgroup_put(child);
-
- return restart_syscall();
- }
} else if (disable & (1 << ssid)) {
if (!(cgrp->subtree_control & (1 << ssid))) {
disable &= ~(1 << ssid);
@@ -2758,19 +2777,48 @@
* subsystems than specified may need to be enabled or disabled
* depending on subsystem dependencies.
*/
- cgrp->subtree_control |= enable;
- cgrp->subtree_control &= ~disable;
+ old_sc = cgrp->subtree_control;
+ old_ss = cgrp->child_subsys_mask;
+ new_sc = (old_sc | enable) & ~disable;
+ new_ss = cgroup_calc_child_subsys_mask(cgrp, new_sc);
- old_ctrl = cgrp->child_subsys_mask;
- cgroup_refresh_child_subsys_mask(cgrp);
- new_ctrl = cgrp->child_subsys_mask;
-
- css_enable = ~old_ctrl & new_ctrl;
- css_disable = old_ctrl & ~new_ctrl;
+ css_enable = ~old_ss & new_ss;
+ css_disable = old_ss & ~new_ss;
enable |= css_enable;
disable |= css_disable;
/*
+ * Because css offlining is asynchronous, userland might try to
+ * re-enable the same controller while the previous instance is
+ * still around. In such cases, wait till it's gone using
+ * offline_waitq.
+ */
+ for_each_subsys(ss, ssid) {
+ if (!(css_enable & (1 << ssid)))
+ continue;
+
+ cgroup_for_each_live_child(child, cgrp) {
+ DEFINE_WAIT(wait);
+
+ if (!cgroup_css(child, ss))
+ continue;
+
+ cgroup_get(child);
+ prepare_to_wait(&child->offline_waitq, &wait,
+ TASK_UNINTERRUPTIBLE);
+ cgroup_kn_unlock(of->kn);
+ schedule();
+ finish_wait(&child->offline_waitq, &wait);
+ cgroup_put(child);
+
+ return restart_syscall();
+ }
+ }
+
+ cgrp->subtree_control = new_sc;
+ cgrp->child_subsys_mask = new_ss;
+
+ /*
* Create new csses or make the existing ones visible. A css is
* created invisible if it's being implicitly enabled through
* dependency. An invisible css is made visible when the userland
@@ -2825,6 +2873,24 @@
}
}
+ /*
+ * The effective csses of all the descendants (excluding @cgrp) may
+ * have changed. Subsystems can optionally subscribe to this event
+ * by implementing ->css_e_css_changed() which is invoked if any of
+ * the effective csses seen from the css's cgroup may have changed.
+ */
+ for_each_subsys(ss, ssid) {
+ struct cgroup_subsys_state *this_css = cgroup_css(cgrp, ss);
+ struct cgroup_subsys_state *css;
+
+ if (!ss->css_e_css_changed || !this_css)
+ continue;
+
+ css_for_each_descendant_pre(css, this_css)
+ if (css != this_css)
+ ss->css_e_css_changed(css);
+ }
+
kernfs_activate(cgrp->kn);
ret = 0;
out_unlock:
@@ -2832,9 +2898,8 @@
return ret ?: nbytes;
err_undo_css:
- cgrp->subtree_control &= ~enable;
- cgrp->subtree_control |= disable;
- cgroup_refresh_child_subsys_mask(cgrp);
+ cgrp->subtree_control = old_sc;
+ cgrp->child_subsys_mask = old_ss;
for_each_subsys(ss, ssid) {
if (!(enable & (1 << ssid)))
@@ -4370,6 +4435,8 @@
if (ss) {
/* css release path */
cgroup_idr_remove(&ss->css_idr, css->id);
+ if (ss->css_released)
+ ss->css_released(css);
} else {
/* cgroup release path */
cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 723cfc9..64b257f 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -248,34 +248,34 @@
if (is_cpuset_online(((des_cs) = css_cs((pos_css)))))
/*
- * There are two global mutexes guarding cpuset structures - cpuset_mutex
- * and callback_mutex. The latter may nest inside the former. We also
- * require taking task_lock() when dereferencing a task's cpuset pointer.
- * See "The task_lock() exception", at the end of this comment.
+ * There are two global locks guarding cpuset structures - cpuset_mutex and
+ * callback_lock. We also require taking task_lock() when dereferencing a
+ * task's cpuset pointer. See "The task_lock() exception", at the end of this
+ * comment.
*
- * A task must hold both mutexes to modify cpusets. If a task holds
+ * A task must hold both locks to modify cpusets. If a task holds
* cpuset_mutex, then it blocks others wanting that mutex, ensuring that it
- * is the only task able to also acquire callback_mutex and be able to
+ * is the only task able to also acquire callback_lock and be able to
* modify cpusets. It can perform various checks on the cpuset structure
* first, knowing nothing will change. It can also allocate memory while
* just holding cpuset_mutex. While it is performing these checks, various
- * callback routines can briefly acquire callback_mutex to query cpusets.
- * Once it is ready to make the changes, it takes callback_mutex, blocking
+ * callback routines can briefly acquire callback_lock to query cpusets.
+ * Once it is ready to make the changes, it takes callback_lock, blocking
* everyone else.
*
* Calls to the kernel memory allocator can not be made while holding
- * callback_mutex, as that would risk double tripping on callback_mutex
+ * callback_lock, as that would risk double tripping on callback_lock
* from one of the callbacks into the cpuset code from within
* __alloc_pages().
*
- * If a task is only holding callback_mutex, then it has read-only
+ * If a task is only holding callback_lock, then it has read-only
* access to cpusets.
*
* Now, the task_struct fields mems_allowed and mempolicy may be changed
* by other task, we use alloc_lock in the task_struct fields to protect
* them.
*
- * The cpuset_common_file_read() handlers only hold callback_mutex across
+ * The cpuset_common_file_read() handlers only hold callback_lock across
* small pieces of code, such as when reading out possibly multi-word
* cpumasks and nodemasks.
*
@@ -284,7 +284,7 @@
*/
static DEFINE_MUTEX(cpuset_mutex);
-static DEFINE_MUTEX(callback_mutex);
+static DEFINE_SPINLOCK(callback_lock);
/*
* CPU / memory hotplug is handled asynchronously.
@@ -329,7 +329,7 @@
* One way or another, we guarantee to return some non-empty subset
* of cpu_online_mask.
*
- * Call with callback_mutex held.
+ * Call with callback_lock or cpuset_mutex held.
*/
static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
{
@@ -347,7 +347,7 @@
* One way or another, we guarantee to return some non-empty subset
* of node_states[N_MEMORY].
*
- * Call with callback_mutex held.
+ * Call with callback_lock or cpuset_mutex held.
*/
static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
{
@@ -359,7 +359,7 @@
/*
* update task's spread flag if cpuset's page/slab spread flag is set
*
- * Called with callback_mutex/cpuset_mutex held
+ * Call with callback_lock or cpuset_mutex held.
*/
static void cpuset_update_task_spread_flag(struct cpuset *cs,
struct task_struct *tsk)
@@ -886,9 +886,9 @@
continue;
rcu_read_unlock();
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cpumask_copy(cp->effective_cpus, new_cpus);
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
WARN_ON(!cgroup_on_dfl(cp->css.cgroup) &&
!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
@@ -953,9 +953,9 @@
if (retval < 0)
return retval;
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
/* use trialcs->cpus_allowed as a temp variable */
update_cpumasks_hier(cs, trialcs->cpus_allowed);
@@ -1142,9 +1142,9 @@
continue;
rcu_read_unlock();
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cp->effective_mems = *new_mems;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
WARN_ON(!cgroup_on_dfl(cp->css.cgroup) &&
!nodes_equal(cp->mems_allowed, cp->effective_mems));
@@ -1165,7 +1165,7 @@
* mempolicies and if the cpuset is marked 'memory_migrate',
* migrate the tasks pages to the new memory.
*
- * Call with cpuset_mutex held. May take callback_mutex during call.
+ * Call with cpuset_mutex held. May take callback_lock during call.
* Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
* lock each such tasks mm->mmap_sem, scan its vma's and rebind
* their mempolicies to the cpusets new mems_allowed.
@@ -1212,9 +1212,9 @@
if (retval < 0)
goto done;
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cs->mems_allowed = trialcs->mems_allowed;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
/* use trialcs->mems_allowed as a temp variable */
update_nodemasks_hier(cs, &cs->mems_allowed);
@@ -1305,9 +1305,9 @@
spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
|| (is_spread_page(cs) != is_spread_page(trialcs)));
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cs->flags = trialcs->flags;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
rebuild_sched_domains_locked();
@@ -1714,7 +1714,7 @@
count = seq_get_buf(sf, &buf);
s = buf;
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
switch (type) {
case FILE_CPULIST:
@@ -1741,7 +1741,7 @@
seq_commit(sf, -1);
}
out_unlock:
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
return ret;
}
@@ -1958,12 +1958,12 @@
cpuset_inc();
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
if (cgroup_on_dfl(cs->css.cgroup)) {
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
cs->effective_mems = parent->effective_mems;
}
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
goto out_unlock;
@@ -1990,10 +1990,10 @@
}
rcu_read_unlock();
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cs->mems_allowed = parent->mems_allowed;
cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
out_unlock:
mutex_unlock(&cpuset_mutex);
return 0;
@@ -2032,7 +2032,7 @@
static void cpuset_bind(struct cgroup_subsys_state *root_css)
{
mutex_lock(&cpuset_mutex);
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
if (cgroup_on_dfl(root_css->cgroup)) {
cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
@@ -2043,7 +2043,7 @@
top_cpuset.mems_allowed = top_cpuset.effective_mems;
}
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
mutex_unlock(&cpuset_mutex);
}
@@ -2128,12 +2128,12 @@
{
bool is_empty;
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cpumask_copy(cs->cpus_allowed, new_cpus);
cpumask_copy(cs->effective_cpus, new_cpus);
cs->mems_allowed = *new_mems;
cs->effective_mems = *new_mems;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
/*
* Don't call update_tasks_cpumask() if the cpuset becomes empty,
@@ -2170,10 +2170,10 @@
if (nodes_empty(*new_mems))
*new_mems = parent_cs(cs)->effective_mems;
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
cpumask_copy(cs->effective_cpus, new_cpus);
cs->effective_mems = *new_mems;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
if (cpus_updated)
update_tasks_cpumask(cs);
@@ -2259,21 +2259,21 @@
/* synchronize cpus_allowed to cpu_active_mask */
if (cpus_updated) {
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
if (!on_dfl)
cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
cpumask_copy(top_cpuset.effective_cpus, &new_cpus);
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
/* we don't mess with cpumasks of tasks in top_cpuset */
}
/* synchronize mems_allowed to N_MEMORY */
if (mems_updated) {
- mutex_lock(&callback_mutex);
+ spin_lock_irq(&callback_lock);
if (!on_dfl)
top_cpuset.mems_allowed = new_mems;
top_cpuset.effective_mems = new_mems;
- mutex_unlock(&callback_mutex);
+ spin_unlock_irq(&callback_lock);
update_tasks_nodemask(&top_cpuset);
}
@@ -2366,11 +2366,13 @@
void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
{
- mutex_lock(&callback_mutex);
+ unsigned long flags;
+
+ spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
guarantee_online_cpus(task_cs(tsk), pmask);
rcu_read_unlock();
- mutex_unlock(&callback_mutex);
+ spin_unlock_irqrestore(&callback_lock, flags);
}
void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
@@ -2416,12 +2418,13 @@
nodemask_t cpuset_mems_allowed(struct task_struct *tsk)
{
nodemask_t mask;
+ unsigned long flags;
- mutex_lock(&callback_mutex);
+ spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
guarantee_online_mems(task_cs(tsk), &mask);
rcu_read_unlock();
- mutex_unlock(&callback_mutex);
+ spin_unlock_irqrestore(&callback_lock, flags);
return mask;
}
@@ -2440,7 +2443,7 @@
/*
* nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or
* mem_hardwall ancestor to the specified cpuset. Call holding
- * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall
+ * callback_lock. If no ancestor is mem_exclusive or mem_hardwall
* (an unusual configuration), then returns the root cpuset.
*/
static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs)
@@ -2451,7 +2454,7 @@
}
/**
- * cpuset_node_allowed_softwall - Can we allocate on a memory node?
+ * cpuset_node_allowed - Can we allocate on a memory node?
* @node: is this an allowed node?
* @gfp_mask: memory allocation flags
*
@@ -2463,13 +2466,6 @@
* flag, yes.
* Otherwise, no.
*
- * 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_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
* (in get_page_from_freelist()) refusing to consider the zones for
@@ -2482,13 +2478,12 @@
* GFP_KERNEL allocations are not so marked, so can escape to the
* nearest enclosing hardwalled ancestor cpuset.
*
- * Scanning up parent cpusets requires callback_mutex. The
+ * Scanning up parent cpusets requires callback_lock. The
* __alloc_pages() routine only calls here with __GFP_HARDWALL bit
* _not_ set if it's a GFP_KERNEL allocation, and all nodes in the
* current tasks mems_allowed came up empty on the first pass over
* the zonelist. So only GFP_KERNEL allocations, if all nodes in the
- * cpuset are short of memory, might require taking the callback_mutex
- * mutex.
+ * cpuset are short of memory, might require taking the callback_lock.
*
* The first call here from mm/page_alloc:get_page_from_freelist()
* has __GFP_HARDWALL set in gfp_mask, enforcing hardwall cpusets,
@@ -2505,20 +2500,15 @@
* TIF_MEMDIE - any node ok
* GFP_KERNEL - any node in enclosing hardwalled cpuset ok
* GFP_USER - only nodes in current tasks mems allowed ok.
- *
- * Rule:
- * 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_node_allowed_softwall(int node, gfp_t gfp_mask)
+int __cpuset_node_allowed(int node, gfp_t gfp_mask)
{
struct cpuset *cs; /* current cpuset ancestors */
int allowed; /* is allocation in zone z allowed? */
+ unsigned long flags;
if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
return 1;
- might_sleep_if(!(gfp_mask & __GFP_HARDWALL));
if (node_isset(node, current->mems_allowed))
return 1;
/*
@@ -2534,55 +2524,17 @@
return 1;
/* Not hardwall and node outside mems_allowed: scan up cpusets */
- mutex_lock(&callback_mutex);
+ spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
cs = nearest_hardwall_ancestor(task_cs(current));
allowed = node_isset(node, cs->mems_allowed);
rcu_read_unlock();
- mutex_unlock(&callback_mutex);
+ spin_unlock_irqrestore(&callback_lock, flags);
return allowed;
}
-/*
- * 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 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
- * (in get_page_from_freelist()) refusing to consider the zones for
- * 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_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_node_allowed_hardwall(int node, gfp_t gfp_mask)
-{
- if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
- return 1;
- if (node_isset(node, current->mems_allowed))
- return 1;
- /*
- * Allow tasks that have access to memory reserves because they have
- * been OOM killed to get memory anywhere.
- */
- if (unlikely(test_thread_flag(TIF_MEMDIE)))
- return 1;
- return 0;
-}
-
/**
* cpuset_mem_spread_node() - On which node to begin search for a file page
* cpuset_slab_spread_node() - On which node to begin search for a slab page
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 30cd968..919b86a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -582,7 +582,7 @@
for_each_zone_zonelist_nodemask(zone, z, zonelist,
MAX_NR_ZONES - 1, nodemask) {
- if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask(h))) {
+ if (cpuset_zone_allowed(zone, htlb_alloc_mask(h))) {
page = dequeue_huge_page_node(h, zone_to_nid(zone));
if (page) {
if (avoid_reserve)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 3b014d3..864bba9 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -233,7 +233,7 @@
/* Check this allocation failure is caused by cpuset's wall function */
for_each_zone_zonelist_nodemask(zone, z, zonelist,
high_zoneidx, nodemask)
- if (!cpuset_zone_allowed_softwall(zone, gfp_mask))
+ if (!cpuset_zone_allowed(zone, gfp_mask))
cpuset_limited = true;
if (cpuset_limited) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a7198c0..df542fe 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1990,7 +1990,7 @@
/*
* Scan zonelist, looking for a zone with enough free.
- * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
+ * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
*/
for_each_zone_zonelist_nodemask(zone, z, zonelist,
high_zoneidx, nodemask) {
@@ -2001,7 +2001,7 @@
continue;
if (cpusets_enabled() &&
(alloc_flags & ALLOC_CPUSET) &&
- !cpuset_zone_allowed_softwall(zone, gfp_mask))
+ !cpuset_zone_allowed(zone, gfp_mask))
continue;
/*
* Distribute pages in proportion to the individual
@@ -2529,7 +2529,7 @@
alloc_flags |= ALLOC_HARDER;
/*
* Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
- * comment for __cpuset_node_allowed_softwall().
+ * comment for __cpuset_node_allowed().
*/
alloc_flags &= ~ALLOC_CPUSET;
} else if (unlikely(rt_task(current)) && !in_interrupt())
diff --git a/mm/slab.c b/mm/slab.c
index 79e15f0..fee275b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3015,7 +3015,7 @@
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
nid = zone_to_nid(zone);
- if (cpuset_zone_allowed_hardwall(zone, flags) &&
+ if (cpuset_zone_allowed(zone, flags | __GFP_HARDWALL) &&
get_node(cache, nid) &&
get_node(cache, nid)->free_objects) {
obj = ____cache_alloc_node(cache,
diff --git a/mm/slub.c b/mm/slub.c
index 386bbed..765c588 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1665,7 +1665,8 @@
n = get_node(s, zone_to_nid(zone));
- if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
+ if (n && cpuset_zone_allowed(zone,
+ flags | __GFP_HARDWALL) &&
n->nr_partial > s->min_partial) {
object = get_partial_node(s, n, c, flags);
if (object) {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4636d9e..a384339 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2405,7 +2405,8 @@
* to global LRU.
*/
if (global_reclaim(sc)) {
- if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ if (!cpuset_zone_allowed(zone,
+ GFP_KERNEL | __GFP_HARDWALL))
continue;
lru_pages += zone_reclaimable_pages(zone);
@@ -3388,7 +3389,7 @@
if (!populated_zone(zone))
return;
- if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ if (!cpuset_zone_allowed(zone, GFP_KERNEL | __GFP_HARDWALL))
return;
pgdat = zone->zone_pgdat;
if (pgdat->kswapd_max_order < order) {