X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fcpuset.c;h=f76db9dcaa05e592f3138f5389ae4c22827b58d9;hb=2d29c6a075787f2c1bc49b86a084d2b878f72fc4;hp=203ca52e78dd54512333cb7fa9065eaec8399516;hpb=029190c515f15f512ac85de8fc686d4dbd0ae731;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 203ca52..f76db9d 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -14,6 +14,8 @@ * 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 @@ -34,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -54,7 +57,16 @@ #include #include #include -#include +#include +#include + +/* + * 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. @@ -63,7 +75,7 @@ */ int number_of_cpusets __read_mostly; -/* Retrieve the cpuset from a cgroup */ +/* Forward declare cgroup structures */ struct cgroup_subsys cpuset_subsys; struct cpuset; @@ -80,7 +92,7 @@ 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 */ @@ -95,6 +107,12 @@ struct cpuset { /* 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 */ @@ -110,12 +128,16 @@ static inline struct cpuset *task_cs(struct task_struct *task) return container_of(task_subsys_state(task, cpuset_subsys_id), struct cpuset, css); } - +struct cpuset_hotplug_scanner { + struct cgroup_scanner scan; + struct cgroup *to; +}; /* bits in struct cpuset flags field */ typedef enum { CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, + CS_MEM_HARDWALL, CS_MEMORY_MIGRATE, CS_SCHED_LOAD_BALANCE, CS_SPREAD_PAGE, @@ -133,6 +155,11 @@ static inline int is_mem_exclusive(const struct cpuset *cs) 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); @@ -159,39 +186,40 @@ static inline int is_spread_slab(const struct cpuset *cs) * 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. @@ -207,67 +235,32 @@ static struct cpuset top_cpuset = { * 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) @@ -291,7 +284,7 @@ static struct file_system_type cpuset_fs_type = { }; /* - * 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, @@ -304,15 +297,16 @@ static struct file_system_type cpuset_fs_type = { * 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)); } /* @@ -353,15 +347,14 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) * 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 @@ -389,14 +382,9 @@ void cpuset_update_task_memory_state(void) 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); @@ -423,17 +411,48 @@ void cpuset_update_task_memory_state(void) * * 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. @@ -441,7 +460,7 @@ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) * 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 @@ -475,12 +494,15 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) 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 && @@ -488,37 +510,73 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) 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; } /* - * 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 @@ -526,16 +584,10 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) * 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 @@ -567,50 +619,71 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) * 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); } } @@ -641,105 +714,266 @@ restart: } } - /* Convert to */ - doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL); + /* + * Now we know how many domains to create. + * Convert to 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; +} + +/* + * 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(); + + /* 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(); +} + +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); } /* - * Call with manage_mutex held. May take callback_mutex during call. + * 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); +} -static int update_cpumask(struct cpuset *cs, char *buf) +/** + * 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 cpuset trialcs; + 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; } @@ -751,11 +985,11 @@ static int update_cpumask(struct cpuset *cs, char *buf) * 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(). @@ -792,93 +1026,30 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, mutex_unlock(&callback_mutex); } -/* - * 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 - * task in the cpuset, rebind any vma mempolicies and if - * 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. - * 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) +/** + * 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 + * + * Called with cgroup_mutex held + * Return 0 if successful, -errno if not. + */ +static int update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem) { - 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; + int retval; - /* - * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY]; - * it's read-only - */ - 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. - */ - if (!buf[0] || (buf[0] == '\n' && !buf[1])) { - nodes_clear(trialcs.mems_allowed); - } else { - 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; - } - } - /* - * 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)) { - 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; - goto done; - } - retval = validate_change(cs, &trialcs); - if (retval < 0) - goto done; - - mutex_lock(&callback_mutex); - cs->mems_allowed = trialcs.mems_allowed; - cs->mems_generation = cpuset_mems_generation++; - mutex_unlock(&callback_mutex); - - cpuset_being_rebound = cs; /* causes mpol_copy() rebind */ + cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ fudge = 10; /* spare mmarray[] slots */ - fudge += cpus_weight(cs->cpus_allowed); /* imagine one fork-bomb/cpu */ + fudge += cpumask_weight(cs->cpus_allowed);/* imagine 1 fork-bomb/cpu */ retval = -ENOMEM; /* @@ -926,10 +1097,10 @@ static int update_nodemask(struct cpuset *cs, char *buf) * 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() + * tasklist_lock. Forks can happen again now - the mpol_dup() * cpuset_being_rebound check will catch such forks, and rebind * their vma mempolicies too. Because we still hold the global - * cpuset manage_mutex, we know that no other rebind effort will + * 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. @@ -940,11 +1111,11 @@ static int update_nodemask(struct cpuset *cs, char *buf) mpol_rebind_mm(mm, &cs->mems_allowed); if (migrate) - cpuset_migrate_mm(mm, &oldmem, &cs->mems_allowed); + cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed); mmput(mm); } - /* We're done rebinding vma's to this cpusets new mems_allowed. */ + /* We're done rebinding vmas to this cpuset's new mems_allowed. */ kfree(mmarray); cpuset_being_rebound = NULL; retval = 0; @@ -952,67 +1123,130 @@ done: return retval; } +/* + * 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 + * task in the cpuset, rebind any vma mempolicies and if + * the cpuset is marked 'memory_migrate', migrate the tasks + * pages to the new memory. + * + * 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 int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, + const char *buf) +{ + nodemask_t oldmem; + int retval; + + /* + * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY]; + * it's read-only + */ + if (cs == &top_cpuset) + return -EACCES; + + /* + * 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) { + nodes_clear(trialcs->mems_allowed); + } else { + retval = nodelist_parse(buf, trialcs->mems_allowed); + if (retval < 0) + goto done; + + if (!nodes_subset(trialcs->mems_allowed, + node_states[N_HIGH_MEMORY])) + return -EINVAL; + } + oldmem = cs->mems_allowed; + if (nodes_equal(oldmem, trialcs->mems_allowed)) { + retval = 0; /* Too easy - nothing to do */ + goto done; + } + retval = validate_change(cs, trialcs); + if (retval < 0) + goto done; + + mutex_lock(&callback_mutex); + cs->mems_allowed = trialcs->mems_allowed; + cs->mems_generation = cpuset_mems_generation++; + mutex_unlock(&callback_mutex); + + retval = update_tasks_nodemask(cs, &oldmem); +done: + return retval; +} + int current_cpuset_is_being_rebound(void) { 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; + if (val < -1 || val >= SD_LV_MAX) + return -EINVAL; + + 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; } /* @@ -1113,31 +1347,49 @@ static int fmeter_getrate(struct fmeter *fmp) 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); + int ret = 0; - if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) + if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) return -ENOSPC; - return security_task_setscheduler(tsk, 0, NULL); + if (tsk->flags & PF_THREAD_BOUND) { + mutex_lock(&callback_mutex); + if (!cpumask_equal(&tsk->cpus_allowed, cs->cpus_allowed)) + ret = -EINVAL; + mutex_unlock(&callback_mutex); + } + + return ret < 0 ? ret : security_task_setscheduler(tsk, 0, NULL); } static void cpuset_attach(struct cgroup_subsys *ss, 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; @@ -1148,7 +1400,6 @@ static void cpuset_attach(struct cgroup_subsys *ss, cpuset_migrate_mm(mm, &from, &to); mmput(mm); } - } /* The various types of files and directories in a cpuset file system */ @@ -1159,89 +1410,114 @@ typedef enum { 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; } @@ -1259,13 +1535,13 @@ out1: 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) @@ -1303,30 +1579,6 @@ static ssize_t cpuset_common_file_read(struct cgroup *cont, 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; @@ -1339,111 +1591,157 @@ 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, + }, + + { + .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; } /* @@ -1460,7 +1758,8 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont) * 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) @@ -1478,17 +1777,14 @@ static void cpuset_post_clone(struct cgroup_subsys *ss, 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( @@ -1507,6 +1803,10 @@ 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; @@ -1515,10 +1815,11 @@ static struct cgroup_subsys_state *cpuset_create( 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++; @@ -1526,15 +1827,9 @@ static struct cgroup_subsys_state *cpuset_create( } /* - * 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) @@ -1544,16 +1839,17 @@ 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, @@ -1570,6 +1866,8 @@ struct cgroup_subsys cpuset_subsys = { int __init cpuset_init_early(void) { + alloc_bootmem_cpumask_var(&top_cpuset.cpus_allowed); + top_cpuset.mems_generation = cpuset_mems_generation++; return 0; } @@ -1585,86 +1883,159 @@ int __init cpuset_init(void) { 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 cpuset_hotplug_scanner *chsp; + + chsp = container_of(scan, struct cpuset_hotplug_scanner, scan); + cgroup_attach_task(chsp->to, 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 cpuset_hotplug_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.scan.cg = from->css.cgroup; + scan.scan.test_task = NULL; /* select all tasks in cgroup */ + scan.scan.process_task = cpuset_do_move_task; + scan.scan.heap = NULL; + scan.to = to->css.cgroup; + + if (cgroup_scan_tasks(&scan.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; + + /* + * 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; -static void common_cpu_mem_hotplug_unplug(void) + 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); + } + } } /* @@ -1675,29 +2046,63 @@ static void common_cpu_mem_hotplug_unplug(void) * * 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(); + cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask); + 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: + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; + break; + case MEM_OFFLINE: + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; + scan_for_empty_cpusets(&top_cpuset); + break; + default: + break; + } + cgroup_unlock(); + return NOTIFY_OK; } #endif @@ -1709,39 +2114,48 @@ void cpuset_track_online_nodes(void) 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); } /** @@ -1768,33 +2182,25 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk) } /** - * 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; } @@ -1808,7 +2214,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * __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. + * hardwalled cpuset ancestor to this tasks cpuset, yes. * If the task has been OOM killed and has access to memory reserves * as specified by the TIF_MEMDIE flag, yes. * Otherwise, no. @@ -1831,7 +2237,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * 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 @@ -1854,7 +2260,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * 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: @@ -1891,7 +2297,7 @@ int __cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask) 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); @@ -2023,6 +2429,29 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, 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 @@ -2063,10 +2492,8 @@ void __cpuset_memory_pressure_bump(void) * - Used for /proc//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) { @@ -2119,13 +2546,18 @@ const struct file_operations proc_cpuset_operations = { #endif /* CONFIG_PROC_PID_CPUSET */ /* Display task cpus_allowed, mems_allowed in /proc//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"); }