* 2003-10-22 Updates by Stephen Hemminger.
* 2004 May-July Rework by Paul Jackson.
* 2006 Rework by Paul Menage to use generic cgroups
+ * 2008 Rework of the scheduler domains and CPU hotplug handling
+ * by Max Krasnyansky
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of the Linux
#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>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <linux/mutex.h>
-#include <linux/kfifo.h>
+#include <linux/workqueue.h>
+#include <linux/cgroup.h>
+
+/*
+ * Workqueue for cpuset related tasks.
+ *
+ * Using kevent workqueue may cause deadlock when memory_migrate
+ * is set. So we create a separate workqueue thread for cpuset.
+ */
+static struct workqueue_struct *cpuset_wq;
/*
* Tracks how many cpusets are currently defined in system.
*/
int number_of_cpusets __read_mostly;
-/* Retrieve the cpuset from a cgroup */
+/* Forward declare cgroup structures */
struct cgroup_subsys cpuset_subsys;
struct cpuset;
struct cgroup_subsys_state css;
unsigned long flags; /* "unsigned long" so bitops work */
- cpumask_t cpus_allowed; /* CPUs allowed to tasks in cpuset */
+ cpumask_var_t cpus_allowed; /* CPUs allowed to tasks in cpuset */
nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */
struct cpuset *parent; /* my parent */
/* partition number for rebuild_sched_domains() */
int pn;
+
+ /* for custom sched domain */
+ int relax_domain_level;
+
+ /* used for walking a cpuset heirarchy */
+ struct list_head stack_list;
};
/* Retrieve the cpuset for a cgroup */
struct cpuset, css);
}
-
/* bits in struct cpuset flags field */
typedef enum {
CS_CPU_EXCLUSIVE,
CS_MEM_EXCLUSIVE,
+ CS_MEM_HARDWALL,
CS_MEMORY_MIGRATE,
CS_SCHED_LOAD_BALANCE,
CS_SPREAD_PAGE,
return test_bit(CS_MEM_EXCLUSIVE, &cs->flags);
}
+static inline int is_mem_hardwall(const struct cpuset *cs)
+{
+ return test_bit(CS_MEM_HARDWALL, &cs->flags);
+}
+
static inline int is_sched_load_balance(const struct cpuset *cs)
{
return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
* number, and avoid having to lock and reload mems_allowed unless
* the cpuset they're using changes generation.
*
- * A single, global generation is needed because attach_task() could
+ * A single, global generation is needed because cpuset_attach_task() could
* reattach a task to a different cpuset, which must not have its
* generation numbers aliased with those of that tasks previous cpuset.
*
* Generations are needed for mems_allowed because one task cannot
- * modify anothers memory placement. So we must enable every task,
+ * modify another's memory placement. So we must enable every task,
* on every visit to __alloc_pages(), to efficiently check whether
* its current->cpuset->mems_allowed has changed, requiring an update
* of its current->mems_allowed.
*
- * Since cpuset_mems_generation is guarded by manage_mutex,
+ * Since writes to cpuset_mems_generation are guarded by the cgroup lock
* there is no need to mark it atomic.
*/
static int cpuset_mems_generation;
static struct cpuset top_cpuset = {
.flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)),
- .cpus_allowed = CPU_MASK_ALL,
- .mems_allowed = NODE_MASK_ALL,
};
/*
- * We have two global cpuset mutexes below. They can nest.
- * It is ok to first take manage_mutex, then nest callback_mutex. We also
- * require taking task_lock() when dereferencing a tasks cpuset pointer.
- * See "The task_lock() exception", at the end of this comment.
+ * There are two global mutexes guarding cpuset structures. The first
+ * is the main control groups cgroup_mutex, accessed via
+ * cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific
+ * callback_mutex, below. They can nest. It is ok to first take
+ * cgroup_mutex, then nest callback_mutex. 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 manage_mutex, then it blocks others wanting that mutex,
+ * holds cgroup_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 modify cpusets. It can perform various checks on
* the cpuset structure first, knowing nothing will change. It can
- * also allocate memory while just holding manage_mutex. While it is
+ * also allocate memory while just holding cgroup_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 everyone else.
* The task_struct fields mems_allowed and mems_generation may only
* be accessed in the context of that task, so require no locks.
*
- * Any task can increment and decrement the count field without lock.
- * So in general, code holding manage_mutex or callback_mutex can't rely
- * on the count field not changing. However, if the count goes to
- * zero, then only attach_task(), which holds both mutexes, can
- * increment it again. Because a count of zero means that no tasks
- * are currently attached, therefore there is no way a task attached
- * to that cpuset can fork (the other way to increment the count).
- * So code holding manage_mutex or callback_mutex can safely assume that
- * if the count is zero, it will stay zero. Similarly, if a task
- * holds manage_mutex or callback_mutex on a cpuset with zero count, it
- * knows that the cpuset won't be removed, as cpuset_rmdir() needs
- * both of those mutexes.
- *
- * The cpuset_common_file_write handler for operations that modify
- * the cpuset hierarchy holds manage_mutex across the entire operation,
- * single threading all such cpuset modifications across the system.
- *
* The cpuset_common_file_read() handlers only hold callback_mutex across
* small pieces of code, such as when reading out possibly multi-word
* cpumasks and nodemasks.
*
- * The fork and exit callbacks cpuset_fork() and cpuset_exit(), don't
- * (usually) take either mutex. These are the two most performance
- * critical pieces of code here. The exception occurs on cpuset_exit(),
- * when a task in a notify_on_release cpuset exits. Then manage_mutex
- * is taken, and if the cpuset count is zero, a usermode call made
- * to /sbin/cpuset_release_agent with the name of the cpuset (path
- * relative to the root of cpuset file system) as the argument.
- *
- * A cpuset can only be deleted if both its 'count' of using tasks
- * is zero, and its list of 'children' cpusets is empty. Since all
- * tasks in the system use _some_ cpuset, and since there is always at
- * least one task in the system (init), therefore, top_cpuset
- * always has either children cpusets and/or using tasks. So we don't
- * need a special hack to ensure that top_cpuset cannot be deleted.
- *
- * The above "Tale of Two Semaphores" would be complete, but for:
- *
- * The task_lock() exception
- *
- * The need for this exception arises from the action of attach_task(),
- * which overwrites one tasks cpuset pointer with another. It does
- * so using both mutexes, however there are several performance
- * critical places that need to reference task->cpuset without the
- * expense of grabbing a system global mutex. Therefore except as
- * noted below, when dereferencing or, as in attach_task(), modifying
- * a tasks cpuset pointer we use task_lock(), which acts on a spinlock
- * (task->alloc_lock) already in the task_struct routinely used for
- * such matters.
- *
- * P.S. One more locking exception. RCU is used to guard the
- * update of a tasks cpuset pointer by attach_task() and the
- * access of task->cpuset->mems_generation via that pointer in
- * the routine cpuset_update_task_memory_state().
+ * Accessing a task's cpuset should be done in accordance with the
+ * guidelines for accessing subsystem state in kernel/cgroup.c
*/
static DEFINE_MUTEX(callback_mutex);
-/* This is ugly, but preserves the userspace API for existing cpuset
+/*
+ * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist
+ * buffers. They are statically allocated to prevent using excess stack
+ * when calling cpuset_print_task_mems_allowed().
+ */
+#define CPUSET_NAME_LEN (128)
+#define CPUSET_NODELIST_LEN (256)
+static char cpuset_name[CPUSET_NAME_LEN];
+static char cpuset_nodelist[CPUSET_NODELIST_LEN];
+static DEFINE_SPINLOCK(cpuset_buffer_lock);
+
+/*
+ * This is ugly, but preserves the userspace API for existing cpuset
* users. If someone tries to mount the "cpuset" filesystem, we
- * silently switch it to mount "cgroup" instead */
+ * silently switch it to mount "cgroup" instead
+ */
static int cpuset_get_sb(struct file_system_type *fs_type,
int flags, const char *unused_dev_name,
void *data, struct vfsmount *mnt)
};
/*
- * Return in *pmask the portion of a cpusets's cpus_allowed that
+ * Return in pmask the portion of a cpusets's cpus_allowed that
* are online. If none are online, walk up the cpuset hierarchy
* until we find one that does have some online cpus. If we get
* all the way to the top and still haven't found any online cpus,
* Call with callback_mutex held.
*/
-static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask)
+static void guarantee_online_cpus(const struct cpuset *cs,
+ struct cpumask *pmask)
{
- while (cs && !cpus_intersects(cs->cpus_allowed, cpu_online_map))
+ while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
cs = cs->parent;
if (cs)
- cpus_and(*pmask, cs->cpus_allowed, cpu_online_map);
+ cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
else
- *pmask = cpu_online_map;
- BUG_ON(!cpus_intersects(*pmask, cpu_online_map));
+ cpumask_copy(pmask, cpu_online_mask);
+ BUG_ON(!cpumask_intersects(pmask, cpu_online_mask));
}
/*
* Do not call this routine if in_interrupt().
*
* Call without callback_mutex or task_lock() held. May be
- * called with or without manage_mutex held. Thanks in part to
- * 'the_top_cpuset_hack', the tasks cpuset pointer will never
- * be NULL. This routine also might acquire callback_mutex and
- * current->mm->mmap_sem during call.
+ * called with or without cgroup_mutex held. Thanks in part to
+ * 'the_top_cpuset_hack', the task's cpuset pointer will never
+ * be NULL. This routine also might acquire callback_mutex during
+ * call.
*
* Reading current->cpuset->mems_generation doesn't need task_lock
* to guard the current->cpuset derefence, because it is guarded
- * from concurrent freeing of current->cpuset by attach_task(),
- * using RCU.
+ * from concurrent freeing of current->cpuset using RCU.
*
* The rcu_dereference() is technically probably not needed,
* as I don't actually mind if I see a new cpuset pointer but
struct task_struct *tsk = current;
struct cpuset *cs;
- if (task_cs(tsk) == &top_cpuset) {
- /* Don't need rcu for top_cpuset. It's never freed. */
- my_cpusets_mem_gen = top_cpuset.mems_generation;
- } else {
- rcu_read_lock();
- my_cpusets_mem_gen = task_cs(current)->mems_generation;
- rcu_read_unlock();
- }
+ rcu_read_lock();
+ my_cpusets_mem_gen = task_cs(tsk)->mems_generation;
+ rcu_read_unlock();
if (my_cpusets_mem_gen != tsk->cpuset_mems_generation) {
mutex_lock(&callback_mutex);
*
* One cpuset is a subset of another if all its allowed CPUs and
* Memory Nodes are a subset of the other, and its exclusive flags
- * are only set if the other's are set. Call holding manage_mutex.
+ * are only set if the other's are set. Call holding cgroup_mutex.
*/
static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
{
- return cpus_subset(p->cpus_allowed, q->cpus_allowed) &&
+ return cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
nodes_subset(p->mems_allowed, q->mems_allowed) &&
is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
is_mem_exclusive(p) <= is_mem_exclusive(q);
}
+/**
+ * alloc_trial_cpuset - allocate a trial cpuset
+ * @cs: the cpuset that the trial cpuset duplicates
+ */
+static struct cpuset *alloc_trial_cpuset(const struct cpuset *cs)
+{
+ struct cpuset *trial;
+
+ trial = kmemdup(cs, sizeof(*cs), GFP_KERNEL);
+ if (!trial)
+ return NULL;
+
+ if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL)) {
+ kfree(trial);
+ return NULL;
+ }
+ cpumask_copy(trial->cpus_allowed, cs->cpus_allowed);
+
+ return trial;
+}
+
+/**
+ * free_trial_cpuset - free the trial cpuset
+ * @trial: the trial cpuset to be freed
+ */
+static void free_trial_cpuset(struct cpuset *trial)
+{
+ free_cpumask_var(trial->cpus_allowed);
+ kfree(trial);
+}
+
/*
* validate_change() - Used to validate that any proposed cpuset change
* follows the structural rules for cpusets.
* If we replaced the flag and mask values of the current cpuset
* (cur) with those values in the trial cpuset (trial), would
* our various subset and exclusive rules still be valid? Presumes
- * manage_mutex held.
+ * cgroup_mutex held.
*
* 'cur' is the address of an actual, in-use cpuset. Operations
* such as list traversal that depend on the actual address of the
if (!is_cpuset_subset(trial, par))
return -EACCES;
- /* If either I or some sibling (!= me) is exclusive, we can't overlap */
+ /*
+ * If either I or some sibling (!= me) is exclusive, we can't
+ * overlap
+ */
list_for_each_entry(cont, &par->css.cgroup->children, sibling) {
c = cgroup_cs(cont);
if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
c != cur &&
- cpus_intersects(trial->cpus_allowed, c->cpus_allowed))
+ cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
return -EINVAL;
if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
c != cur &&
return -EINVAL;
}
+ /* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */
+ if (cgroup_task_count(cur->css.cgroup)) {
+ if (cpumask_empty(trial->cpus_allowed) ||
+ nodes_empty(trial->mems_allowed)) {
+ return -ENOSPC;
+ }
+ }
+
return 0;
}
+#ifdef CONFIG_SMP
/*
- * Helper routine for rebuild_sched_domains().
+ * Helper routine for generate_sched_domains().
* Do cpusets a, b have overlapping cpus_allowed masks?
*/
-
static int cpusets_overlap(struct cpuset *a, struct cpuset *b)
{
- return cpus_intersects(a->cpus_allowed, b->cpus_allowed);
+ return cpumask_intersects(a->cpus_allowed, b->cpus_allowed);
+}
+
+static void
+update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c)
+{
+ if (dattr->relax_domain_level < c->relax_domain_level)
+ dattr->relax_domain_level = c->relax_domain_level;
+ return;
+}
+
+static void
+update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
+{
+ LIST_HEAD(q);
+
+ list_add(&c->stack_list, &q);
+ while (!list_empty(&q)) {
+ struct cpuset *cp;
+ struct cgroup *cont;
+ struct cpuset *child;
+
+ cp = list_first_entry(&q, struct cpuset, stack_list);
+ list_del(q.next);
+
+ if (cpumask_empty(cp->cpus_allowed))
+ continue;
+
+ if (is_sched_load_balance(cp))
+ update_domain_attr(dattr, cp);
+
+ list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
+ child = cgroup_cs(cont);
+ list_add_tail(&child->stack_list, &q);
+ }
+ }
}
/*
- * rebuild_sched_domains()
- *
- * If the flag 'sched_load_balance' of any cpuset with non-empty
- * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset
- * which has that flag enabled, or if any cpuset with a non-empty
- * 'cpus' is removed, then call this routine to rebuild the
- * scheduler's dynamic sched domains.
+ * generate_sched_domains()
*
- * This routine builds a partial partition of the systems CPUs
- * (the set of non-overlappping cpumask_t's in the array 'part'
- * below), and passes that partial partition to the kernel/sched.c
- * partition_sched_domains() routine, which will rebuild the
- * schedulers load balancing domains (sched domains) as specified
- * by that partial partition. A 'partial partition' is a set of
- * non-overlapping subsets whose union is a subset of that set.
+ * This function builds a partial partition of the systems CPUs
+ * A 'partial partition' is a set of non-overlapping subsets whose
+ * union is a subset of that set.
+ * The output of this function needs to be passed to kernel/sched.c
+ * partition_sched_domains() routine, which will rebuild the scheduler's
+ * load balancing domains (sched domains) as specified by that partial
+ * partition.
*
- * See "What is sched_load_balance" in Documentation/cpusets.txt
+ * See "What is sched_load_balance" in Documentation/cgroups/cpusets.txt
* for a background explanation of this.
*
* Does not return errors, on the theory that the callers of this
* domains when operating in the severe memory shortage situations
* that could cause allocation failures below.
*
- * Call with cgroup_mutex held. May take callback_mutex during
- * call due to the kfifo_alloc() and kmalloc() calls. May nest
- * a call to the lock_cpu_hotplug()/unlock_cpu_hotplug() pair.
- * Must not be called holding callback_mutex, because we must not
- * call lock_cpu_hotplug() while holding callback_mutex. Elsewhere
- * the kernel nests callback_mutex inside lock_cpu_hotplug() calls.
- * So the reverse nesting would risk an ABBA deadlock.
+ * Must be called with cgroup_lock held.
*
* The three key local variables below are:
- * q - a kfifo queue of cpuset pointers, used to implement a
+ * q - a linked-list queue of cpuset pointers, used to implement a
* top-down scan of all cpusets. This scan loads a pointer
* to each cpuset marked is_sched_load_balance into the
* array 'csa'. For our purposes, rebuilding the schedulers
* element of the partition (one sched domain) to be passed to
* partition_sched_domains().
*/
-
-static void rebuild_sched_domains(void)
+/* FIXME: see the FIXME in partition_sched_domains() */
+static int generate_sched_domains(struct cpumask **domains,
+ struct sched_domain_attr **attributes)
{
- struct kfifo *q; /* queue of cpusets to be scanned */
+ LIST_HEAD(q); /* queue of cpusets to be scanned */
struct cpuset *cp; /* scans q */
struct cpuset **csa; /* array of all cpuset ptrs */
int csn; /* how many cpuset ptrs in csa so far */
int i, j, k; /* indices for partition finding loops */
- cpumask_t *doms; /* resulting partition; i.e. sched domains */
- int ndoms; /* number of sched domains in result */
- int nslot; /* next empty doms[] cpumask_t slot */
+ struct cpumask *doms; /* resulting partition; i.e. sched domains */
+ struct sched_domain_attr *dattr; /* attributes for custom domains */
+ int ndoms = 0; /* number of sched domains in result */
+ int nslot; /* next empty doms[] struct cpumask slot */
- q = NULL;
- csa = NULL;
doms = NULL;
+ dattr = NULL;
+ csa = NULL;
/* Special case for the 99% of systems with one, full, sched domain */
if (is_sched_load_balance(&top_cpuset)) {
- ndoms = 1;
- doms = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
+ doms = kmalloc(cpumask_size(), GFP_KERNEL);
if (!doms)
- goto rebuild;
- *doms = top_cpuset.cpus_allowed;
- goto rebuild;
- }
+ goto done;
+
+ dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL);
+ if (dattr) {
+ *dattr = SD_ATTR_INIT;
+ update_domain_attr_tree(dattr, &top_cpuset);
+ }
+ cpumask_copy(doms, top_cpuset.cpus_allowed);
- q = kfifo_alloc(number_of_cpusets * sizeof(cp), GFP_KERNEL, NULL);
- if (IS_ERR(q))
+ ndoms = 1;
goto done;
+ }
+
csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL);
if (!csa)
goto done;
csn = 0;
- cp = &top_cpuset;
- __kfifo_put(q, (void *)&cp, sizeof(cp));
- while (__kfifo_get(q, (void *)&cp, sizeof(cp))) {
+ list_add(&top_cpuset.stack_list, &q);
+ while (!list_empty(&q)) {
struct cgroup *cont;
struct cpuset *child; /* scans child cpusets of cp */
- if (is_sched_load_balance(cp))
+
+ cp = list_first_entry(&q, struct cpuset, stack_list);
+ list_del(q.next);
+
+ if (cpumask_empty(cp->cpus_allowed))
+ continue;
+
+ /*
+ * All child cpusets contain a subset of the parent's cpus, so
+ * just skip them, and then we call update_domain_attr_tree()
+ * to calc relax_domain_level of the corresponding sched
+ * domain.
+ */
+ if (is_sched_load_balance(cp)) {
csa[csn++] = cp;
+ continue;
+ }
+
list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
child = cgroup_cs(cont);
- __kfifo_put(q, (void *)&child, sizeof(cp));
+ list_add_tail(&child->stack_list, &q);
}
}
}
}
- /* Convert <csn, csa> to <ndoms, doms> */
- doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL);
+ /*
+ * Now we know how many domains to create.
+ * Convert <csn, csa> to <ndoms, doms> and populate cpu masks.
+ */
+ doms = kmalloc(ndoms * cpumask_size(), GFP_KERNEL);
if (!doms)
- goto rebuild;
+ goto done;
+
+ /*
+ * The rest of the code, including the scheduler, can deal with
+ * dattr==NULL case. No need to abort if alloc fails.
+ */
+ dattr = kmalloc(ndoms * sizeof(struct sched_domain_attr), GFP_KERNEL);
for (nslot = 0, i = 0; i < csn; i++) {
struct cpuset *a = csa[i];
+ struct cpumask *dp;
int apn = a->pn;
- if (apn >= 0) {
- cpumask_t *dp = doms + nslot;
-
- if (nslot == ndoms) {
- static int warnings = 10;
- if (warnings) {
- printk(KERN_WARNING
- "rebuild_sched_domains confused:"
- " nslot %d, ndoms %d, csn %d, i %d,"
- " apn %d\n",
- nslot, ndoms, csn, i, apn);
- warnings--;
- }
- continue;
+ if (apn < 0) {
+ /* Skip completed partitions */
+ continue;
+ }
+
+ dp = doms + nslot;
+
+ if (nslot == ndoms) {
+ static int warnings = 10;
+ if (warnings) {
+ printk(KERN_WARNING
+ "rebuild_sched_domains confused:"
+ " nslot %d, ndoms %d, csn %d, i %d,"
+ " apn %d\n",
+ nslot, ndoms, csn, i, apn);
+ warnings--;
}
+ continue;
+ }
+
+ cpumask_clear(dp);
+ if (dattr)
+ *(dattr + nslot) = SD_ATTR_INIT;
+ for (j = i; j < csn; j++) {
+ struct cpuset *b = csa[j];
- cpus_clear(*dp);
- for (j = i; j < csn; j++) {
- struct cpuset *b = csa[j];
+ if (apn == b->pn) {
+ cpumask_or(dp, dp, b->cpus_allowed);
+ if (dattr)
+ update_domain_attr_tree(dattr + nslot, b);
- if (apn == b->pn) {
- cpus_or(*dp, *dp, b->cpus_allowed);
- b->pn = -1;
- }
+ /* Done with this partition */
+ b->pn = -1;
}
- nslot++;
}
+ nslot++;
}
BUG_ON(nslot != ndoms);
-rebuild:
- /* Have scheduler rebuild sched domains */
- lock_cpu_hotplug();
- partition_sched_domains(ndoms, doms);
- unlock_cpu_hotplug();
-
done:
- if (q && !IS_ERR(q))
- kfifo_free(q);
kfree(csa);
- /* Don't kfree(doms) -- partition_sched_domains() does that. */
+
+ /*
+ * 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;
}
/*
- * Call with manage_mutex held. May take callback_mutex during call.
+ * Rebuild scheduler domains.
+ *
+ * Call with neither cgroup_mutex held nor within get_online_cpus().
+ * Takes both cgroup_mutex and get_online_cpus().
+ *
+ * Cannot be directly called from cpuset code handling changes
+ * to the cpuset pseudo-filesystem, because it cannot be called
+ * from code that already holds cgroup_mutex.
*/
+static void do_rebuild_sched_domains(struct work_struct *unused)
+{
+ struct sched_domain_attr *attr;
+ struct cpumask *doms;
+ int ndoms;
+
+ get_online_cpus();
-static int update_cpumask(struct cpuset *cs, char *buf)
+ /* Generate domain masks and attrs */
+ cgroup_lock();
+ ndoms = generate_sched_domains(&doms, &attr);
+ cgroup_unlock();
+
+ /* Have scheduler rebuild the domains */
+ partition_sched_domains(ndoms, doms, attr);
+
+ 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)
{
- struct cpuset trialcs;
+ *domains = NULL;
+ return 1;
+}
+#endif /* CONFIG_SMP */
+
+static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains);
+
+/*
+ * Rebuild scheduler domains, asynchronously via workqueue.
+ *
+ * If the flag 'sched_load_balance' of any cpuset with non-empty
+ * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset
+ * which has that flag enabled, or if any cpuset with a non-empty
+ * 'cpus' is removed, then call this routine to rebuild the
+ * scheduler's dynamic sched domains.
+ *
+ * The rebuild_sched_domains() and partition_sched_domains()
+ * routines must nest cgroup_lock() inside get_online_cpus(),
+ * but such cpuset changes as these must nest that locking the
+ * other way, holding cgroup_lock() for much of the code.
+ *
+ * So in order to avoid an ABBA deadlock, the cpuset code handling
+ * these user changes delegates the actual sched domain rebuilding
+ * to a separate workqueue thread, which ends up processing the
+ * above do_rebuild_sched_domains() function.
+ */
+static void async_rebuild_sched_domains(void)
+{
+ queue_work(cpuset_wq, &rebuild_sched_domains_work);
+}
+
+/*
+ * Accomplishes the same scheduler domain rebuild as the above
+ * async_rebuild_sched_domains(), however it directly calls the
+ * rebuild routine synchronously rather than calling it via an
+ * asynchronous work thread.
+ *
+ * This can only be called from code that is not holding
+ * cgroup_mutex (not nested in a cgroup_lock() call.)
+ */
+void rebuild_sched_domains(void)
+{
+ do_rebuild_sched_domains(NULL);
+}
+
+/**
+ * cpuset_test_cpumask - test a task's cpus_allowed versus its cpuset's
+ * @tsk: task to test
+ * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
+ *
+ * Call with cgroup_mutex held. May take callback_mutex during call.
+ * Called for each task in a cgroup by cgroup_scan_tasks().
+ * Return nonzero if this tasks's cpus_allowed mask should be changed (in other
+ * words, if its mask is not equal to its cpuset's mask).
+ */
+static int cpuset_test_cpumask(struct task_struct *tsk,
+ struct cgroup_scanner *scan)
+{
+ return !cpumask_equal(&tsk->cpus_allowed,
+ (cgroup_cs(scan->cg))->cpus_allowed);
+}
+
+/**
+ * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's
+ * @tsk: task to test
+ * @scan: struct cgroup_scanner containing the cgroup of the task
+ *
+ * Called by cgroup_scan_tasks() for each task in a cgroup whose
+ * cpus_allowed mask needs to be changed.
+ *
+ * We don't need to re-check for the cgroup/cpuset membership, since we're
+ * holding cgroup_lock() at this point.
+ */
+static void cpuset_change_cpumask(struct task_struct *tsk,
+ struct cgroup_scanner *scan)
+{
+ set_cpus_allowed_ptr(tsk, ((cgroup_cs(scan->cg))->cpus_allowed));
+}
+
+/**
+ * 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.
+ *
+ * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * if @heap != NULL.
+ */
+static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
+{
+ struct cgroup_scanner scan;
+
+ scan.cg = cs->css.cgroup;
+ scan.test_task = cpuset_test_cpumask;
+ scan.process_task = cpuset_change_cpumask;
+ scan.heap = heap;
+ cgroup_scan_tasks(&scan);
+}
+
+/**
+ * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it
+ * @cs: the cpuset to consider
+ * @buf: buffer of cpu numbers written to this cpuset
+ */
+static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
+ const char *buf)
+{
+ struct ptr_heap heap;
int retval;
- int cpus_changed, is_load_balanced;
+ int is_load_balanced;
/* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
if (cs == &top_cpuset)
return -EACCES;
- trialcs = *cs;
-
/*
- * We allow a cpuset's cpus_allowed to be empty; if it has attached
- * tasks, we'll catch it later when we validate the change and return
- * -ENOSPC.
+ * An empty cpus_allowed is ok only if the cpuset has no tasks.
+ * Since cpulist_parse() fails on an empty mask, we special case
+ * that parsing. The validate_change() call ensures that cpusets
+ * with tasks have cpus.
*/
- if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
- cpus_clear(trialcs.cpus_allowed);
+ if (!*buf) {
+ cpumask_clear(trialcs->cpus_allowed);
} else {
- retval = cpulist_parse(buf, trialcs.cpus_allowed);
+ retval = cpulist_parse(buf, trialcs->cpus_allowed);
if (retval < 0)
return retval;
+
+ if (!cpumask_subset(trialcs->cpus_allowed, cpu_online_mask))
+ return -EINVAL;
}
- cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
- /* cpus_allowed cannot be empty for a cpuset with attached tasks. */
- if (cgroup_task_count(cs->css.cgroup) &&
- cpus_empty(trialcs.cpus_allowed))
- return -ENOSPC;
- retval = validate_change(cs, &trialcs);
+ retval = validate_change(cs, trialcs);
if (retval < 0)
return retval;
- cpus_changed = !cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed);
- is_load_balanced = is_sched_load_balance(&trialcs);
+ /* Nothing to do if the cpus didn't change */
+ if (cpumask_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);
- cs->cpus_allowed = trialcs.cpus_allowed;
+ cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
mutex_unlock(&callback_mutex);
- if (cpus_changed && is_load_balanced)
- rebuild_sched_domains();
+ /*
+ * Scan tasks in the cpuset, and update the cpumasks of any
+ * that need an update.
+ */
+ update_tasks_cpumask(cs, &heap);
+ heap_free(&heap);
+
+ if (is_load_balanced)
+ async_rebuild_sched_domains();
return 0;
}
* Temporarilly set tasks mems_allowed to target nodes of migration,
* so that the migration code can allocate pages on these nodes.
*
- * Call holding manage_mutex, so our current->cpuset won't change
- * during this call, as manage_mutex holds off any attach_task()
+ * Call holding cgroup_mutex, so current's cpuset won't change
+ * during this call, as manage_mutex holds off any cpuset_attach()
* calls. Therefore we don't need to take task_lock around the
* call to guarantee_online_mems(), as we know no one is changing
- * our tasks cpuset.
+ * our task's cpuset.
*
* Hold callback_mutex around the two modifications of our tasks
* mems_allowed to synchronize with cpuset_mems_allowed().
}
/*
+ * 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
+ * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * if @heap != NULL.
+ */
+static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
+ struct ptr_heap *heap)
+{
+ struct cgroup_scanner scan;
+
+ cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
+
+ scan.cg = cs->css.cgroup;
+ scan.test_task = NULL;
+ scan.process_task = cpuset_change_nodemask;
+ scan.heap = heap;
+ scan.data = (nodemask_t *)oldmem;
+
+ /*
+ * 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.
+ */
+ cgroup_scan_tasks(&scan);
+
+ /* We're done rebinding vmas to this cpuset's new mems_allowed. */
+ cpuset_being_rebound = NULL;
+}
+
+/*
* Handle user request to change the 'mems' memory placement
* of a cpuset. Needs to validate the request, update the
* cpusets mems_allowed and mems_generation, and for each
* the cpuset is marked 'memory_migrate', migrate the tasks
* pages to the new memory.
*
- * Call with manage_mutex held. May take callback_mutex during call.
+ * Call with cgroup_mutex held. May take callback_mutex 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.
*/
-
-static void *cpuset_being_rebound;
-
-static int update_nodemask(struct cpuset *cs, char *buf)
+static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
+ const char *buf)
{
- struct cpuset trialcs;
nodemask_t oldmem;
- struct task_struct *p;
- struct mm_struct **mmarray;
- int i, n, ntasks;
- int migrate;
- int fudge;
int retval;
- struct cgroup_iter it;
+ struct ptr_heap heap;
/*
* top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
if (cs == &top_cpuset)
return -EACCES;
- trialcs = *cs;
-
/*
- * We allow a cpuset's mems_allowed to be empty; if it has attached
- * tasks, we'll catch it later when we validate the change and return
- * -ENOSPC.
+ * An empty mems_allowed is ok iff there are no tasks in the cpuset.
+ * Since nodelist_parse() fails on an empty mask, we special case
+ * that parsing. The validate_change() call ensures that cpusets
+ * with tasks have memory.
*/
- if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
- nodes_clear(trialcs.mems_allowed);
+ if (!*buf) {
+ nodes_clear(trialcs->mems_allowed);
} else {
- retval = nodelist_parse(buf, trialcs.mems_allowed);
+ retval = nodelist_parse(buf, trialcs->mems_allowed);
if (retval < 0)
goto done;
- if (!nodes_intersects(trialcs.mems_allowed,
- node_states[N_HIGH_MEMORY])) {
- /*
- * error if only memoryless nodes specified.
- */
- retval = -ENOSPC;
- goto done;
- }
+
+ if (!nodes_subset(trialcs->mems_allowed,
+ node_states[N_HIGH_MEMORY]))
+ return -EINVAL;
}
- /*
- * Exclude memoryless nodes. We know that trialcs.mems_allowed
- * contains at least one node with memory.
- */
- nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
- node_states[N_HIGH_MEMORY]);
oldmem = cs->mems_allowed;
- if (nodes_equal(oldmem, trialcs.mems_allowed)) {
+ if (nodes_equal(oldmem, trialcs->mems_allowed)) {
retval = 0; /* Too easy - nothing to do */
goto done;
}
- /* mems_allowed cannot be empty for a cpuset with attached tasks. */
- if (cgroup_task_count(cs->css.cgroup) &&
- nodes_empty(trialcs.mems_allowed)) {
- retval = -ENOSPC;
+ retval = validate_change(cs, trialcs);
+ if (retval < 0)
goto done;
- }
- retval = validate_change(cs, &trialcs);
+
+ 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_allowed = trialcs->mems_allowed;
cs->mems_generation = cpuset_mems_generation++;
mutex_unlock(&callback_mutex);
- cpuset_being_rebound = cs; /* causes mpol_copy() rebind */
+ update_tasks_nodemask(cs, &oldmem, &heap);
- fudge = 10; /* spare mmarray[] slots */
- fudge += cpus_weight(cs->cpus_allowed); /* imagine one 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);
-
- /*
- * 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_copy()
- * cpuset_being_rebound check will catch such forks, and rebind
- * their vma mempolicies too. Because we still hold the global
- * cpuset manage_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);
- }
-
- /* We're done rebinding vma's to this cpusets new mems_allowed. */
- kfree(mmarray);
- cpuset_being_rebound = NULL;
- retval = 0;
+ heap_free(&heap);
done:
return retval;
}
return task_cs(current) == cpuset_being_rebound;
}
-/*
- * Call with manage_mutex held.
- */
-
-static int update_memory_pressure_enabled(struct cpuset *cs, char *buf)
+static int update_relax_domain_level(struct cpuset *cs, s64 val)
{
- if (simple_strtoul(buf, NULL, 10) != 0)
- cpuset_memory_pressure_enabled = 1;
- else
- cpuset_memory_pressure_enabled = 0;
+#ifdef CONFIG_SMP
+ if (val < -1 || val >= SD_LV_MAX)
+ return -EINVAL;
+#endif
+
+ if (val != cs->relax_domain_level) {
+ cs->relax_domain_level = val;
+ if (!cpumask_empty(cs->cpus_allowed) &&
+ is_sched_load_balance(cs))
+ async_rebuild_sched_domains();
+ }
+
return 0;
}
/*
* update_flag - read a 0 or a 1 in a file and update associated flag
- * bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
- * CS_SCHED_LOAD_BALANCE,
- * CS_NOTIFY_ON_RELEASE, CS_MEMORY_MIGRATE,
- * CS_SPREAD_PAGE, CS_SPREAD_SLAB)
- * cs: the cpuset to update
- * buf: the buffer where we read the 0 or 1
- *
- * Call with manage_mutex held.
+ * bit: the bit to update (see cpuset_flagbits_t)
+ * cs: the cpuset to update
+ * turning_on: whether the flag is being set or cleared
+ *
+ * Call with cgroup_mutex held.
*/
-static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
+static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
+ int turning_on)
{
- int turning_on;
- struct cpuset trialcs;
+ struct cpuset *trialcs;
int err;
- int cpus_nonempty, balance_flag_changed;
+ int balance_flag_changed;
- turning_on = (simple_strtoul(buf, NULL, 10) != 0);
+ trialcs = alloc_trial_cpuset(cs);
+ if (!trialcs)
+ return -ENOMEM;
- trialcs = *cs;
if (turning_on)
- set_bit(bit, &trialcs.flags);
+ set_bit(bit, &trialcs->flags);
else
- clear_bit(bit, &trialcs.flags);
+ clear_bit(bit, &trialcs->flags);
- err = validate_change(cs, &trialcs);
+ err = validate_change(cs, trialcs);
if (err < 0)
- return err;
+ goto out;
- cpus_nonempty = !cpus_empty(trialcs.cpus_allowed);
balance_flag_changed = (is_sched_load_balance(cs) !=
- is_sched_load_balance(&trialcs));
+ is_sched_load_balance(trialcs));
mutex_lock(&callback_mutex);
- cs->flags = trialcs.flags;
+ cs->flags = trialcs->flags;
mutex_unlock(&callback_mutex);
- if (cpus_nonempty && balance_flag_changed)
- rebuild_sched_domains();
+ if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
+ async_rebuild_sched_domains();
- return 0;
+out:
+ free_trial_cpuset(trialcs);
+ return err;
}
/*
return val;
}
+/* Protected by cgroup_lock */
+static cpumask_var_t cpus_attach;
+
+/* 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)
{
struct cpuset *cs = cgroup_cs(cont);
- if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
+ 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;
+
return security_task_setscheduler(tsk, 0, NULL);
}
struct cgroup *cont, struct cgroup *oldcont,
struct task_struct *tsk)
{
- cpumask_t cpus;
nodemask_t from, to;
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
struct cpuset *oldcs = cgroup_cs(oldcont);
+ int err;
- mutex_lock(&callback_mutex);
- guarantee_online_cpus(cs, &cpus);
- set_cpus_allowed(tsk, cpus);
- mutex_unlock(&callback_mutex);
+ if (cs == &top_cpuset) {
+ cpumask_copy(cpus_attach, cpu_possible_mask);
+ } else {
+ mutex_lock(&callback_mutex);
+ guarantee_online_cpus(cs, cpus_attach);
+ mutex_unlock(&callback_mutex);
+ }
+ err = set_cpus_allowed_ptr(tsk, cpus_attach);
+ if (err)
+ return;
from = oldcs->mems_allowed;
to = cs->mems_allowed;
cpuset_migrate_mm(mm, &from, &to);
mmput(mm);
}
-
}
/* The various types of files and directories in a cpuset file system */
FILE_MEMLIST,
FILE_CPU_EXCLUSIVE,
FILE_MEM_EXCLUSIVE,
+ FILE_MEM_HARDWALL,
FILE_SCHED_LOAD_BALANCE,
+ FILE_SCHED_RELAX_DOMAIN_LEVEL,
FILE_MEMORY_PRESSURE_ENABLED,
FILE_MEMORY_PRESSURE,
FILE_SPREAD_PAGE,
FILE_SPREAD_SLAB,
} cpuset_filetype_t;
-static ssize_t cpuset_common_file_write(struct cgroup *cont,
- struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
{
- struct cpuset *cs = cgroup_cs(cont);
- cpuset_filetype_t type = cft->private;
- char *buffer;
int retval = 0;
+ struct cpuset *cs = cgroup_cs(cgrp);
+ cpuset_filetype_t type = cft->private;
- /* Crude upper limit on largest legitimate cpulist user might write. */
- if (nbytes > 100U + 6 * max(NR_CPUS, MAX_NUMNODES))
- return -E2BIG;
-
- /* +1 for nul-terminator */
- if ((buffer = kmalloc(nbytes + 1, GFP_KERNEL)) == 0)
- return -ENOMEM;
-
- if (copy_from_user(buffer, userbuf, nbytes)) {
- retval = -EFAULT;
- goto out1;
- }
- buffer[nbytes] = 0; /* nul-terminate */
-
- cgroup_lock();
-
- if (cgroup_is_removed(cont)) {
- retval = -ENODEV;
- goto out2;
- }
+ if (!cgroup_lock_live_group(cgrp))
+ return -ENODEV;
switch (type) {
- case FILE_CPULIST:
- retval = update_cpumask(cs, buffer);
- break;
- case FILE_MEMLIST:
- retval = update_nodemask(cs, buffer);
- break;
case FILE_CPU_EXCLUSIVE:
- retval = update_flag(CS_CPU_EXCLUSIVE, cs, buffer);
+ retval = update_flag(CS_CPU_EXCLUSIVE, cs, val);
break;
case FILE_MEM_EXCLUSIVE:
- retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer);
+ retval = update_flag(CS_MEM_EXCLUSIVE, cs, val);
+ break;
+ case FILE_MEM_HARDWALL:
+ retval = update_flag(CS_MEM_HARDWALL, cs, val);
break;
case FILE_SCHED_LOAD_BALANCE:
- retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, buffer);
+ retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val);
break;
case FILE_MEMORY_MIGRATE:
- retval = update_flag(CS_MEMORY_MIGRATE, cs, buffer);
+ retval = update_flag(CS_MEMORY_MIGRATE, cs, val);
break;
case FILE_MEMORY_PRESSURE_ENABLED:
- retval = update_memory_pressure_enabled(cs, buffer);
+ cpuset_memory_pressure_enabled = !!val;
break;
case FILE_MEMORY_PRESSURE:
retval = -EACCES;
break;
case FILE_SPREAD_PAGE:
- retval = update_flag(CS_SPREAD_PAGE, cs, buffer);
+ retval = update_flag(CS_SPREAD_PAGE, cs, val);
cs->mems_generation = cpuset_mems_generation++;
break;
case FILE_SPREAD_SLAB:
- retval = update_flag(CS_SPREAD_SLAB, cs, buffer);
+ retval = update_flag(CS_SPREAD_SLAB, cs, val);
cs->mems_generation = cpuset_mems_generation++;
break;
default:
retval = -EINVAL;
- goto out2;
+ break;
+ }
+ cgroup_unlock();
+ return retval;
+}
+
+static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
+{
+ int retval = 0;
+ struct cpuset *cs = cgroup_cs(cgrp);
+ cpuset_filetype_t type = cft->private;
+
+ if (!cgroup_lock_live_group(cgrp))
+ return -ENODEV;
+
+ switch (type) {
+ case FILE_SCHED_RELAX_DOMAIN_LEVEL:
+ retval = update_relax_domain_level(cs, val);
+ break;
+ default:
+ retval = -EINVAL;
+ break;
+ }
+ cgroup_unlock();
+ return retval;
+}
+
+/*
+ * Common handling for a write to a "cpus" or "mems" file.
+ */
+static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
+ const char *buf)
+{
+ int retval = 0;
+ struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *trialcs;
+
+ if (!cgroup_lock_live_group(cgrp))
+ return -ENODEV;
+
+ trialcs = alloc_trial_cpuset(cs);
+ if (!trialcs)
+ return -ENOMEM;
+
+ switch (cft->private) {
+ case FILE_CPULIST:
+ retval = update_cpumask(cs, trialcs, buf);
+ break;
+ case FILE_MEMLIST:
+ retval = update_nodemask(cs, trialcs, buf);
+ break;
+ default:
+ retval = -EINVAL;
+ break;
}
- if (retval == 0)
- retval = nbytes;
-out2:
+ free_trial_cpuset(trialcs);
cgroup_unlock();
-out1:
- kfree(buffer);
return retval;
}
static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
{
- cpumask_t mask;
+ int ret;
mutex_lock(&callback_mutex);
- mask = cs->cpus_allowed;
+ ret = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
mutex_unlock(&callback_mutex);
- return cpulist_scnprintf(page, PAGE_SIZE, mask);
+ return ret;
}
static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)
case FILE_MEMLIST:
s += cpuset_sprintf_memlist(s, cs);
break;
- case FILE_CPU_EXCLUSIVE:
- *s++ = is_cpu_exclusive(cs) ? '1' : '0';
- break;
- case FILE_MEM_EXCLUSIVE:
- *s++ = is_mem_exclusive(cs) ? '1' : '0';
- break;
- case FILE_SCHED_LOAD_BALANCE:
- *s++ = is_sched_load_balance(cs) ? '1' : '0';
- break;
- case FILE_MEMORY_MIGRATE:
- *s++ = is_memory_migrate(cs) ? '1' : '0';
- break;
- case FILE_MEMORY_PRESSURE_ENABLED:
- *s++ = cpuset_memory_pressure_enabled ? '1' : '0';
- break;
- case FILE_MEMORY_PRESSURE:
- s += sprintf(s, "%d", fmeter_getrate(&cs->fmeter));
- break;
- case FILE_SPREAD_PAGE:
- *s++ = is_spread_page(cs) ? '1' : '0';
- break;
- case FILE_SPREAD_SLAB:
- *s++ = is_spread_slab(cs) ? '1' : '0';
- break;
default:
retval = -EINVAL;
goto out;
return retval;
}
+static u64 cpuset_read_u64(struct cgroup *cont, struct cftype *cft)
+{
+ struct cpuset *cs = cgroup_cs(cont);
+ cpuset_filetype_t type = cft->private;
+ switch (type) {
+ case FILE_CPU_EXCLUSIVE:
+ return is_cpu_exclusive(cs);
+ case FILE_MEM_EXCLUSIVE:
+ return is_mem_exclusive(cs);
+ case FILE_MEM_HARDWALL:
+ return is_mem_hardwall(cs);
+ case FILE_SCHED_LOAD_BALANCE:
+ return is_sched_load_balance(cs);
+ case FILE_MEMORY_MIGRATE:
+ return is_memory_migrate(cs);
+ case FILE_MEMORY_PRESSURE_ENABLED:
+ return cpuset_memory_pressure_enabled;
+ case FILE_MEMORY_PRESSURE:
+ return fmeter_getrate(&cs->fmeter);
+ case FILE_SPREAD_PAGE:
+ return is_spread_page(cs);
+ case FILE_SPREAD_SLAB:
+ return is_spread_slab(cs);
+ default:
+ BUG();
+ }
+
+ /* Unreachable but makes gcc happy */
+ return 0;
+}
+static s64 cpuset_read_s64(struct cgroup *cont, struct cftype *cft)
+{
+ struct cpuset *cs = cgroup_cs(cont);
+ cpuset_filetype_t type = cft->private;
+ switch (type) {
+ case FILE_SCHED_RELAX_DOMAIN_LEVEL:
+ return cs->relax_domain_level;
+ default:
+ BUG();
+ }
+ /* Unrechable but makes gcc happy */
+ return 0;
+}
/*
* for the common functions, 'private' gives the type of file
*/
-static struct cftype cft_cpus = {
- .name = "cpus",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_CPULIST,
-};
-
-static struct cftype cft_mems = {
- .name = "mems",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_MEMLIST,
-};
-
-static struct cftype cft_cpu_exclusive = {
- .name = "cpu_exclusive",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_CPU_EXCLUSIVE,
-};
-
-static struct cftype cft_mem_exclusive = {
- .name = "mem_exclusive",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_MEM_EXCLUSIVE,
-};
-
-static struct cftype cft_sched_load_balance = {
- .name = "sched_load_balance",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_SCHED_LOAD_BALANCE,
-};
-
-static struct cftype cft_memory_migrate = {
- .name = "memory_migrate",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_MEMORY_MIGRATE,
+static struct cftype files[] = {
+ {
+ .name = "cpus",
+ .read = cpuset_common_file_read,
+ .write_string = cpuset_write_resmask,
+ .max_write_len = (100U + 6 * NR_CPUS),
+ .private = FILE_CPULIST,
+ },
+
+ {
+ .name = "mems",
+ .read = cpuset_common_file_read,
+ .write_string = cpuset_write_resmask,
+ .max_write_len = (100U + 6 * MAX_NUMNODES),
+ .private = FILE_MEMLIST,
+ },
+
+ {
+ .name = "cpu_exclusive",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_CPU_EXCLUSIVE,
+ },
+
+ {
+ .name = "mem_exclusive",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_MEM_EXCLUSIVE,
+ },
+
+ {
+ .name = "mem_hardwall",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_MEM_HARDWALL,
+ },
+
+ {
+ .name = "sched_load_balance",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_SCHED_LOAD_BALANCE,
+ },
+
+ {
+ .name = "sched_relax_domain_level",
+ .read_s64 = cpuset_read_s64,
+ .write_s64 = cpuset_write_s64,
+ .private = FILE_SCHED_RELAX_DOMAIN_LEVEL,
+ },
+
+ {
+ .name = "memory_migrate",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_MEMORY_MIGRATE,
+ },
+
+ {
+ .name = "memory_pressure",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_MEMORY_PRESSURE,
+ .mode = S_IRUGO,
+ },
+
+ {
+ .name = "memory_spread_page",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_SPREAD_PAGE,
+ },
+
+ {
+ .name = "memory_spread_slab",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_SPREAD_SLAB,
+ },
};
static struct cftype cft_memory_pressure_enabled = {
.name = "memory_pressure_enabled",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
.private = FILE_MEMORY_PRESSURE_ENABLED,
};
-static struct cftype cft_memory_pressure = {
- .name = "memory_pressure",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_MEMORY_PRESSURE,
-};
-
-static struct cftype cft_spread_page = {
- .name = "memory_spread_page",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_SPREAD_PAGE,
-};
-
-static struct cftype cft_spread_slab = {
- .name = "memory_spread_slab",
- .read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
- .private = FILE_SPREAD_SLAB,
-};
-
static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont)
{
int err;
- if ((err = cgroup_add_file(cont, ss, &cft_cpus)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_mems)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_cpu_exclusive)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_mem_exclusive)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_memory_migrate)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_sched_load_balance)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_memory_pressure)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_spread_page)) < 0)
- return err;
- if ((err = cgroup_add_file(cont, ss, &cft_spread_slab)) < 0)
+ err = cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
+ if (err)
return err;
/* memory_pressure_enabled is in root cpuset only */
- if (err == 0 && !cont->parent)
+ if (!cont->parent)
err = cgroup_add_file(cont, ss,
- &cft_memory_pressure_enabled);
- return 0;
+ &cft_memory_pressure_enabled);
+ return err;
}
/*
* If this becomes a problem for some users who wish to
* allow that scenario, then cpuset_post_clone() could be
* changed to grant parent->cpus_allowed-sibling_cpus_exclusive
- * (and likewise for mems) to the new cgroup.
+ * (and likewise for mems) to the new cgroup. Called with cgroup_mutex
+ * held.
*/
static void cpuset_post_clone(struct cgroup_subsys *ss,
struct cgroup *cgroup)
parent_cs = cgroup_cs(parent);
cs->mems_allowed = parent_cs->mems_allowed;
- cs->cpus_allowed = parent_cs->cpus_allowed;
+ cpumask_copy(cs->cpus_allowed, parent_cs->cpus_allowed);
return;
}
/*
* cpuset_create - create a cpuset
- * parent: cpuset that will be parent of the new cpuset.
- * name: name of the new cpuset. Will be strcpy'ed.
- * mode: mode to set on new inode
- *
- * Must be called with the mutex on the parent inode held
+ * ss: cpuset cgroup subsystem
+ * cont: control group that the new cpuset will be part of
*/
static struct cgroup_subsys_state *cpuset_create(
cs = kmalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return ERR_PTR(-ENOMEM);
+ if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) {
+ kfree(cs);
+ return ERR_PTR(-ENOMEM);
+ }
cpuset_update_task_memory_state();
cs->flags = 0;
if (is_spread_slab(parent))
set_bit(CS_SPREAD_SLAB, &cs->flags);
set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
- cs->cpus_allowed = CPU_MASK_NONE;
- cs->mems_allowed = NODE_MASK_NONE;
+ cpumask_clear(cs->cpus_allowed);
+ nodes_clear(cs->mems_allowed);
cs->mems_generation = cpuset_mems_generation++;
fmeter_init(&cs->fmeter);
+ cs->relax_domain_level = -1;
cs->parent = parent;
number_of_cpusets++;
}
/*
- * Locking note on the strange update_flag() call below:
- *
* If the cpuset being removed has its flag 'sched_load_balance'
* enabled, then simulate turning sched_load_balance off, which
- * will call rebuild_sched_domains(). The lock_cpu_hotplug()
- * call in rebuild_sched_domains() must not be made while holding
- * callback_mutex. Elsewhere the kernel nests callback_mutex inside
- * lock_cpu_hotplug() calls. So the reverse nesting would risk an
- * ABBA deadlock.
+ * will call async_rebuild_sched_domains().
*/
static void cpuset_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
cpuset_update_task_memory_state();
if (is_sched_load_balance(cs))
- update_flag(CS_SCHED_LOAD_BALANCE, cs, "0");
+ update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
number_of_cpusets--;
+ free_cpumask_var(cs->cpus_allowed);
kfree(cs);
}
struct cgroup_subsys cpuset_subsys = {
.name = "cpuset",
.create = cpuset_create,
- .destroy = cpuset_destroy,
+ .destroy = cpuset_destroy,
.can_attach = cpuset_can_attach,
.attach = cpuset_attach,
.populate = cpuset_populate,
int __init cpuset_init_early(void)
{
+ alloc_bootmem_cpumask_var(&top_cpuset.cpus_allowed);
+
top_cpuset.mems_generation = cpuset_mems_generation++;
return 0;
}
{
int err = 0;
- top_cpuset.cpus_allowed = CPU_MASK_ALL;
- top_cpuset.mems_allowed = NODE_MASK_ALL;
+ cpumask_setall(top_cpuset.cpus_allowed);
+ nodes_setall(top_cpuset.mems_allowed);
fmeter_init(&top_cpuset.fmeter);
top_cpuset.mems_generation = cpuset_mems_generation++;
set_bit(CS_SCHED_LOAD_BALANCE, &top_cpuset.flags);
+ top_cpuset.relax_domain_level = -1;
err = register_filesystem(&cpuset_fs_type);
if (err < 0)
return err;
+ if (!alloc_cpumask_var(&cpus_attach, GFP_KERNEL))
+ BUG();
+
number_of_cpusets = 1;
return 0;
}
-/*
- * If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs
- * or memory nodes, we need to walk over the cpuset hierarchy,
- * removing that CPU or node from all cpusets. If this removes the
- * last CPU or node from a cpuset, then the guarantee_online_cpus()
- * or guarantee_online_mems() code will use that emptied cpusets
- * parent online CPUs or nodes. Cpusets that were already empty of
- * CPUs or nodes are left empty.
+/**
+ * cpuset_do_move_task - move a given task to another cpuset
+ * @tsk: pointer to task_struct the task to move
+ * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
*
- * This routine is intentionally inefficient in a couple of regards.
- * It will check all cpusets in a subtree even if the top cpuset of
- * the subtree has no offline CPUs or nodes. It checks both CPUs and
- * nodes, even though the caller could have been coded to know that
- * only one of CPUs or nodes needed to be checked on a given call.
- * This was done to minimize text size rather than cpu cycles.
+ * Called by cgroup_scan_tasks() for each task in a cgroup.
+ * Return nonzero to stop the walk through the tasks.
+ */
+static void cpuset_do_move_task(struct task_struct *tsk,
+ struct cgroup_scanner *scan)
+{
+ struct cgroup *new_cgroup = scan->data;
+
+ cgroup_attach_task(new_cgroup, tsk);
+}
+
+/**
+ * move_member_tasks_to_cpuset - move tasks from one cpuset to another
+ * @from: cpuset in which the tasks currently reside
+ * @to: cpuset to which the tasks will be moved
*
- * Call with both manage_mutex and callback_mutex held.
+ * Called with cgroup_mutex held
+ * callback_mutex must not be held, as cpuset_attach() will take it.
*
- * Recursive, on depth of cpuset subtree.
+ * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
+ * calling callback functions for each.
*/
-
-static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur)
+static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
{
- struct cgroup *cont;
- struct cpuset *c;
+ struct cgroup_scanner scan;
- /* Each of our child cpusets mems must be online */
- list_for_each_entry(cont, &cur->css.cgroup->children, sibling) {
- c = cgroup_cs(cont);
- guarantee_online_cpus_mems_in_subtree(c);
- if (!cpus_empty(c->cpus_allowed))
- guarantee_online_cpus(c, &c->cpus_allowed);
- if (!nodes_empty(c->mems_allowed))
- guarantee_online_mems(c, &c->mems_allowed);
- }
+ 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))
+ printk(KERN_ERR "move_member_tasks_to_cpuset: "
+ "cgroup_scan_tasks failed\n");
}
/*
- * The cpus_allowed and mems_allowed nodemasks in the top_cpuset track
- * cpu_online_map and node_states[N_HIGH_MEMORY]. Force the top cpuset to
- * track what's online after any CPU or memory node hotplug or unplug
- * event.
- *
- * To ensure that we don't remove a CPU or node from the top cpuset
- * that is currently in use by a child cpuset (which would violate
- * the rule that cpusets must be subsets of their parent), we first
- * call the recursive routine guarantee_online_cpus_mems_in_subtree().
- *
- * Since there are two callers of this routine, one for CPU hotplug
- * events and one for memory node hotplug events, we could have coded
- * two separate routines here. We code it as a single common routine
- * in order to minimize text size.
+ * If CPU and/or memory hotplug handlers, below, unplug any CPUs
+ * or memory nodes, we need to walk over the cpuset hierarchy,
+ * removing that CPU or node from all cpusets. If this removes the
+ * last CPU or node from a cpuset, then move the tasks in the empty
+ * cpuset to its next-highest non-empty parent.
+ *
+ * Called with cgroup_mutex held
+ * callback_mutex must not be held, as cpuset_attach() will take it.
*/
+static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
+{
+ struct cpuset *parent;
+
+ /*
+ * The cgroup's css_sets list is in use if there are tasks
+ * in the cpuset; the list is empty if there are none;
+ * the cs->css.refcnt seems always 0.
+ */
+ if (list_empty(&cs->css.cgroup->css_sets))
+ return;
-static void common_cpu_mem_hotplug_unplug(void)
+ /*
+ * Find its next-highest non-empty parent, (top cpuset
+ * has online cpus, so can't be empty).
+ */
+ parent = cs->parent;
+ while (cpumask_empty(parent->cpus_allowed) ||
+ nodes_empty(parent->mems_allowed))
+ parent = parent->parent;
+
+ move_member_tasks_to_cpuset(cs, parent);
+}
+
+/*
+ * Walk the specified cpuset subtree and look for empty cpusets.
+ * The tasks of such cpuset must be moved to a parent cpuset.
+ *
+ * Called with cgroup_mutex held. We take callback_mutex to modify
+ * cpus_allowed and mems_allowed.
+ *
+ * This walk processes the tree from top to bottom, completing one layer
+ * before dropping down to the next. It always processes a node before
+ * any of its children.
+ *
+ * For now, since we lack memory hot unplug, we'll never see a cpuset
+ * 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(struct cpuset *root)
{
- cgroup_lock();
- mutex_lock(&callback_mutex);
+ LIST_HEAD(queue);
+ struct cpuset *cp; /* scans cpusets being updated */
+ struct cpuset *child; /* scans child cpusets of cp */
+ struct cgroup *cont;
+ nodemask_t oldmems;
- guarantee_online_cpus_mems_in_subtree(&top_cpuset);
- top_cpuset.cpus_allowed = cpu_online_map;
- top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+ list_add_tail((struct list_head *)&root->stack_list, &queue);
- mutex_unlock(&callback_mutex);
- cgroup_unlock();
+ while (!list_empty(&queue)) {
+ cp = list_first_entry(&queue, struct cpuset, stack_list);
+ list_del(queue.next);
+ list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
+ child = cgroup_cs(cont);
+ list_add_tail(&child->stack_list, &queue);
+ }
+
+ /* Continue past cpusets with all cpus, mems online */
+ if (cpumask_subset(cp->cpus_allowed, cpu_online_mask) &&
+ nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
+ continue;
+
+ oldmems = cp->mems_allowed;
+
+ /* Remove offline cpus and mems from this cpuset. */
+ mutex_lock(&callback_mutex);
+ cpumask_and(cp->cpus_allowed, cp->cpus_allowed,
+ cpu_online_mask);
+ nodes_and(cp->mems_allowed, cp->mems_allowed,
+ node_states[N_HIGH_MEMORY]);
+ mutex_unlock(&callback_mutex);
+
+ /* Move tasks from the empty cpuset to a parent */
+ if (cpumask_empty(cp->cpus_allowed) ||
+ nodes_empty(cp->mems_allowed))
+ remove_tasks_in_empty_cpuset(cp);
+ else {
+ update_tasks_cpumask(cp, NULL);
+ update_tasks_nodemask(cp, &oldmems, NULL);
+ }
+ }
}
/*
*
* This routine ensures that top_cpuset.cpus_allowed tracks
* cpu_online_map on each CPU hotplug (cpuhp) event.
+ *
+ * Called within get_online_cpus(). Needs to call cgroup_lock()
+ * before calling generate_sched_domains().
*/
-
-static int cpuset_handle_cpuhp(struct notifier_block *unused_nb,
+static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
unsigned long phase, void *unused_cpu)
{
- if (phase == CPU_DYING || phase == CPU_DYING_FROZEN)
+ struct sched_domain_attr *attr;
+ struct cpumask *doms;
+ int ndoms;
+
+ switch (phase) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ break;
+
+ default:
return NOTIFY_DONE;
+ }
- common_cpu_mem_hotplug_unplug();
- return 0;
+ 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();
+
+ /* Have scheduler rebuild the domains */
+ partition_sched_domains(ndoms, doms, attr);
+
+ return NOTIFY_OK;
}
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Keep top_cpuset.mems_allowed tracking node_states[N_HIGH_MEMORY].
- * Call this routine anytime after you change
- * node_states[N_HIGH_MEMORY].
- * See also the previous routine cpuset_handle_cpuhp().
+ * 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)
{
- common_cpu_mem_hotplug_unplug();
+ cgroup_lock();
+ switch (action) {
+ case MEM_ONLINE:
+ case MEM_OFFLINE:
+ mutex_lock(&callback_mutex);
+ top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+ mutex_unlock(&callback_mutex);
+ if (action == MEM_OFFLINE)
+ scan_for_empty_cpusets(&top_cpuset);
+ break;
+ default:
+ break;
+ }
+ cgroup_unlock();
+ return NOTIFY_OK;
}
#endif
void __init cpuset_init_smp(void)
{
- top_cpuset.cpus_allowed = cpu_online_map;
+ cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- hotcpu_notifier(cpuset_handle_cpuhp, 0);
+ hotcpu_notifier(cpuset_track_online_cpus, 0);
+ hotplug_memory_notifier(cpuset_track_online_nodes, 10);
+
+ cpuset_wq = create_singlethread_workqueue("cpuset");
+ BUG_ON(!cpuset_wq);
}
/**
-
* cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
* @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
+ * @pmask: pointer to struct cpumask variable to receive cpus_allowed set.
*
- * Description: Returns the cpumask_t cpus_allowed of the cpuset
+ * Description: Returns the cpumask_var_t cpus_allowed of the cpuset
* attached to the specified @tsk. Guaranteed to return some non-empty
* subset of cpu_online_map, even if this means going outside the
* tasks cpuset.
**/
-cpumask_t cpuset_cpus_allowed(struct task_struct *tsk)
+void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
{
- cpumask_t mask;
-
mutex_lock(&callback_mutex);
- task_lock(tsk);
- guarantee_online_cpus(task_cs(tsk), &mask);
- task_unlock(tsk);
+ cpuset_cpus_allowed_locked(tsk, pmask);
mutex_unlock(&callback_mutex);
+}
- return mask;
+/**
+ * cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset.
+ * Must be called with callback_mutex held.
+ **/
+void cpuset_cpus_allowed_locked(struct task_struct *tsk, struct cpumask *pmask)
+{
+ task_lock(tsk);
+ guarantee_online_cpus(task_cs(tsk), pmask);
+ task_unlock(tsk);
}
void cpuset_init_current_mems_allowed(void)
{
- current->mems_allowed = NODE_MASK_ALL;
+ nodes_setall(current->mems_allowed);
}
/**
}
/**
- * cpuset_zonelist_valid_mems_allowed - check zonelist vs. curremt mems_allowed
- * @zl: the zonelist to be checked
+ * cpuset_nodemask_valid_mems_allowed - check nodemask vs. curremt mems_allowed
+ * @nodemask: the nodemask to be checked
*
- * Are any of the nodes on zonelist zl allowed in current->mems_allowed?
+ * Are any of the nodes in the nodemask allowed in current->mems_allowed?
*/
-int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
+int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
{
- int i;
-
- for (i = 0; zl->zones[i]; i++) {
- int nid = zone_to_nid(zl->zones[i]);
-
- if (node_isset(nid, current->mems_allowed))
- return 1;
- }
- return 0;
+ return nodes_intersects(*nodemask, current->mems_allowed);
}
/*
- * nearest_exclusive_ancestor() - Returns the nearest mem_exclusive
- * ancestor to the specified cpuset. Call holding callback_mutex.
- * If no ancestor is mem_exclusive (an unusual configuration), then
- * returns the root cpuset.
+ * 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
+ * (an unusual configuration), then returns the root cpuset.
*/
-static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs)
+static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
{
- while (!is_mem_exclusive(cs) && cs->parent)
+ while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent)
cs = cs->parent;
return cs;
}
/**
- * 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
- * mem_exclusive 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
* and do not allow allocations outside the current tasks cpuset
* unless the task has been OOM killed as is marked TIF_MEMDIE.
* GFP_KERNEL allocations are not so marked, so can escape to the
- * nearest enclosing mem_exclusive ancestor cpuset.
+ * nearest enclosing hardwalled ancestor cpuset.
*
* Scanning up parent cpusets requires callback_mutex. The
* __alloc_pages() routine only calls here with __GFP_HARDWALL bit
* in_interrupt - any node ok (current task context irrelevant)
* GFP_ATOMIC - any node ok
* TIF_MEMDIE - any node ok
- * GFP_KERNEL - any node in enclosing mem_exclusive cpuset 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_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;
mutex_lock(&callback_mutex);
task_lock(current);
- cs = nearest_exclusive_ancestor(task_cs(current));
+ cs = nearest_hardwall_ancestor(task_cs(current));
task_unlock(current);
allowed = node_isset(node, cs->mems_allowed);
}
/*
- * 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;
/*
return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed);
}
+/**
+ * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed
+ * @task: pointer to task_struct of some task.
+ *
+ * Description: Prints @task's name, cpuset name, and cached copy of its
+ * mems_allowed to the kernel log. Must hold task_lock(task) to allow
+ * dereferencing task_cs(task).
+ */
+void cpuset_print_task_mems_allowed(struct task_struct *tsk)
+{
+ struct dentry *dentry;
+
+ dentry = task_cs(tsk)->css.cgroup->dentry;
+ spin_lock(&cpuset_buffer_lock);
+ snprintf(cpuset_name, CPUSET_NAME_LEN,
+ dentry ? (const char *)dentry->d_name.name : "/");
+ nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
+ tsk->mems_allowed);
+ printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
+ tsk->comm, cpuset_name, cpuset_nodelist);
+ spin_unlock(&cpuset_buffer_lock);
+}
+
/*
* Collection of memory_pressure is suppressed unless
* this flag is enabled by writing "1" to the special
* - Used for /proc/<pid>/cpuset.
* - No need to task_lock(tsk) on this tsk->cpuset reference, as it
* doesn't really matter if tsk->cpuset changes after we read it,
- * and we take manage_mutex, keeping attach_task() from changing it
- * anyway. No need to check that tsk->cpuset != NULL, thanks to
- * the_top_cpuset_hack in cpuset_exit(), which sets an exiting tasks
- * cpuset to top_cpuset.
+ * and we take cgroup_mutex, keeping cpuset_attach() from changing it
+ * anyway.
*/
static int proc_cpuset_show(struct seq_file *m, void *unused_v)
{
#endif /* CONFIG_PROC_PID_CPUSET */
/* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
-char *cpuset_task_status_allowed(struct task_struct *task, char *buffer)
-{
- buffer += sprintf(buffer, "Cpus_allowed:\t");
- buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed);
- buffer += sprintf(buffer, "\n");
- buffer += sprintf(buffer, "Mems_allowed:\t");
- buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed);
- buffer += sprintf(buffer, "\n");
- return buffer;
+void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task)
+{
+ seq_printf(m, "Cpus_allowed:\t");
+ seq_cpumask(m, &task->cpus_allowed);
+ seq_printf(m, "\n");
+ seq_printf(m, "Cpus_allowed_list:\t");
+ seq_cpumask_list(m, &task->cpus_allowed);
+ seq_printf(m, "\n");
+ seq_printf(m, "Mems_allowed:\t");
+ seq_nodemask(m, &task->mems_allowed);
+ seq_printf(m, "\n");
+ seq_printf(m, "Mems_allowed_list:\t");
+ seq_nodemask_list(m, &task->mems_allowed);
+ seq_printf(m, "\n");
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff