diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup/Makefile | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 17 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 68 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset-internal.h | 305 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset-v1.c | 562 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 1155 | ||||
| -rw-r--r-- | kernel/cgroup/pids.c | 32 | ||||
| -rw-r--r-- | kernel/fork.c | 1 |
8 files changed, 1098 insertions, 1043 deletions
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile index 12f8457ad1f9..a5c9359d516f 100644 --- a/kernel/cgroup/Makefile +++ b/kernel/cgroup/Makefile @@ -5,5 +5,6 @@ obj-$(CONFIG_CGROUP_FREEZER) += legacy_freezer.o obj-$(CONFIG_CGROUP_PIDS) += pids.o obj-$(CONFIG_CGROUP_RDMA) += rdma.o obj-$(CONFIG_CPUSETS) += cpuset.o +obj-$(CONFIG_CPUSETS_V1) += cpuset-v1.o obj-$(CONFIG_CGROUP_MISC) += misc.o obj-$(CONFIG_CGROUP_DEBUG) += debug.o diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index b9dbf6bf2779..e28d5f0d20ed 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -46,6 +46,12 @@ bool cgroup1_ssid_disabled(int ssid) return cgroup_no_v1_mask & (1 << ssid); } +static bool cgroup1_subsys_absent(struct cgroup_subsys *ss) +{ + /* Check also dfl_cftypes for file-less controllers, i.e. perf_event */ + return ss->legacy_cftypes == NULL && ss->dfl_cftypes; +} + /** * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from' * @from: attach to all cgroups of a given task @@ -675,11 +681,14 @@ int proc_cgroupstats_show(struct seq_file *m, void *v) * cgroup_mutex contention. */ - for_each_subsys(ss, i) + for_each_subsys(ss, i) { + if (cgroup1_subsys_absent(ss)) + continue; seq_printf(m, "%s\t%d\t%d\t%d\n", ss->legacy_name, ss->root->hierarchy_id, atomic_read(&ss->root->nr_cgrps), cgroup_ssid_enabled(i)); + } return 0; } @@ -932,7 +941,8 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param) if (ret != -ENOPARAM) return ret; for_each_subsys(ss, i) { - if (strcmp(param->key, ss->legacy_name)) + if (strcmp(param->key, ss->legacy_name) || + cgroup1_subsys_absent(ss)) continue; if (!cgroup_ssid_enabled(i) || cgroup1_ssid_disabled(i)) return invalfc(fc, "Disabled controller '%s'", @@ -1024,7 +1034,8 @@ static int check_cgroupfs_options(struct fs_context *fc) mask = ~((u16)1 << cpuset_cgrp_id); #endif for_each_subsys(ss, i) - if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i)) + if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i) && + !cgroup1_subsys_absent(ss)) enabled |= 1 << i; ctx->subsys_mask &= enabled; diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index c8e4b62b436a..90e50d6d3cf3 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2331,7 +2331,7 @@ static struct file_system_type cgroup2_fs_type = { .fs_flags = FS_USERNS_MOUNT, }; -#ifdef CONFIG_CPUSETS +#ifdef CONFIG_CPUSETS_V1 static const struct fs_context_operations cpuset_fs_context_ops = { .get_tree = cgroup1_get_tree, .free = cgroup_fs_context_free, @@ -3669,12 +3669,40 @@ static int cgroup_events_show(struct seq_file *seq, void *v) static int cgroup_stat_show(struct seq_file *seq, void *v) { struct cgroup *cgroup = seq_css(seq)->cgroup; + struct cgroup_subsys_state *css; + int dying_cnt[CGROUP_SUBSYS_COUNT]; + int ssid; seq_printf(seq, "nr_descendants %d\n", cgroup->nr_descendants); + + /* + * Show the number of live and dying csses associated with each of + * non-inhibited cgroup subsystems that is bound to cgroup v2. + * + * Without proper lock protection, racing is possible. So the + * numbers may not be consistent when that happens. + */ + rcu_read_lock(); + for (ssid = 0; ssid < CGROUP_SUBSYS_COUNT; ssid++) { + dying_cnt[ssid] = -1; + if ((BIT(ssid) & cgrp_dfl_inhibit_ss_mask) || + (cgroup_subsys[ssid]->root != &cgrp_dfl_root)) + continue; + css = rcu_dereference_raw(cgroup->subsys[ssid]); + dying_cnt[ssid] = cgroup->nr_dying_subsys[ssid]; + seq_printf(seq, "nr_subsys_%s %d\n", cgroup_subsys[ssid]->name, + css ? (css->nr_descendants + 1) : 0); + } + seq_printf(seq, "nr_dying_descendants %d\n", cgroup->nr_dying_descendants); - + for (ssid = 0; ssid < CGROUP_SUBSYS_COUNT; ssid++) { + if (dying_cnt[ssid] >= 0) + seq_printf(seq, "nr_dying_subsys_%s %d\n", + cgroup_subsys[ssid]->name, dying_cnt[ssid]); + } + rcu_read_unlock(); return 0; } @@ -4096,7 +4124,7 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, * If namespaces are delegation boundaries, disallow writes to * files in an non-init namespace root from inside the namespace * except for the files explicitly marked delegatable - - * cgroup.procs and cgroup.subtree_control. + * eg. cgroup.procs, cgroup.threads and cgroup.subtree_control. */ if ((cgrp->root->flags & CGRP_ROOT_NS_DELEGATE) && !(cft->flags & CFTYPE_NS_DELEGATABLE) && @@ -5424,6 +5452,8 @@ static void css_release_work_fn(struct work_struct *work) list_del_rcu(&css->sibling); if (ss) { + struct cgroup *parent_cgrp; + /* css release path */ if (!list_empty(&css->rstat_css_node)) { cgroup_rstat_flush(cgrp); @@ -5433,6 +5463,21 @@ static void css_release_work_fn(struct work_struct *work) cgroup_idr_replace(&ss->css_idr, NULL, css->id); if (ss->css_released) ss->css_released(css); + + cgrp->nr_dying_subsys[ss->id]--; + /* + * When a css is released and ready to be freed, its + * nr_descendants must be zero. However, the corresponding + * cgrp->nr_dying_subsys[ss->id] may not be 0 if a subsystem + * is activated and deactivated multiple times with one or + * more of its previous activation leaving behind dying csses. + */ + WARN_ON_ONCE(css->nr_descendants); + parent_cgrp = cgroup_parent(cgrp); + while (parent_cgrp) { + parent_cgrp->nr_dying_subsys[ss->id]--; + parent_cgrp = cgroup_parent(parent_cgrp); + } } else { struct cgroup *tcgrp; @@ -5517,8 +5562,11 @@ static int online_css(struct cgroup_subsys_state *css) rcu_assign_pointer(css->cgroup->subsys[ss->id], css); atomic_inc(&css->online_cnt); - if (css->parent) + if (css->parent) { atomic_inc(&css->parent->online_cnt); + while ((css = css->parent)) + css->nr_descendants++; + } } return ret; } @@ -5540,6 +5588,16 @@ static void offline_css(struct cgroup_subsys_state *css) RCU_INIT_POINTER(css->cgroup->subsys[ss->id], NULL); wake_up_all(&css->cgroup->offline_waitq); + + css->cgroup->nr_dying_subsys[ss->id]++; + /* + * Parent css and cgroup cannot be freed until after the freeing + * of child css, see css_free_rwork_fn(). + */ + while ((css = css->parent)) { + css->nr_descendants--; + css->cgroup->nr_dying_subsys[ss->id]++; + } } /** @@ -6178,7 +6236,7 @@ int __init cgroup_init(void) WARN_ON(register_filesystem(&cgroup_fs_type)); WARN_ON(register_filesystem(&cgroup2_fs_type)); WARN_ON(!proc_create_single("cgroups", 0, NULL, proc_cgroupstats_show)); -#ifdef CONFIG_CPUSETS +#ifdef CONFIG_CPUSETS_V1 WARN_ON(register_filesystem(&cpuset_fs_type)); #endif diff --git a/kernel/cgroup/cpuset-internal.h b/kernel/cgroup/cpuset-internal.h new file mode 100644 index 000000000000..976a8bc3ff60 --- /dev/null +++ b/kernel/cgroup/cpuset-internal.h @@ -0,0 +1,305 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#ifndef __CPUSET_INTERNAL_H +#define __CPUSET_INTERNAL_H + +#include <linux/cgroup.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/cpuset.h> +#include <linux/spinlock.h> +#include <linux/union_find.h> + +/* See "Frequency meter" comments, below. */ + +struct fmeter { + int cnt; /* unprocessed events count */ + int val; /* most recent output value */ + time64_t time; /* clock (secs) when val computed */ + spinlock_t lock; /* guards read or write of above */ +}; + +/* + * Invalid partition error code + */ +enum prs_errcode { + PERR_NONE = 0, + PERR_INVCPUS, + PERR_INVPARENT, + PERR_NOTPART, + PERR_NOTEXCL, + PERR_NOCPUS, + PERR_HOTPLUG, + PERR_CPUSEMPTY, + PERR_HKEEPING, + PERR_ACCESS, +}; + +/* bits in struct cpuset flags field */ +typedef enum { + CS_ONLINE, + CS_CPU_EXCLUSIVE, + CS_MEM_EXCLUSIVE, + CS_MEM_HARDWALL, + CS_MEMORY_MIGRATE, + CS_SCHED_LOAD_BALANCE, + CS_SPREAD_PAGE, + CS_SPREAD_SLAB, +} cpuset_flagbits_t; + +/* The various types of files and directories in a cpuset file system */ + +typedef enum { + FILE_MEMORY_MIGRATE, + FILE_CPULIST, + FILE_MEMLIST, + FILE_EFFECTIVE_CPULIST, + FILE_EFFECTIVE_MEMLIST, + FILE_SUBPARTS_CPULIST, + FILE_EXCLUSIVE_CPULIST, + FILE_EFFECTIVE_XCPULIST, + FILE_ISOLATED_CPULIST, + FILE_CPU_EXCLUSIVE, + FILE_MEM_EXCLUSIVE, + FILE_MEM_HARDWALL, + FILE_SCHED_LOAD_BALANCE, + FILE_PARTITION_ROOT, + FILE_SCHED_RELAX_DOMAIN_LEVEL, + FILE_MEMORY_PRESSURE_ENABLED, + FILE_MEMORY_PRESSURE, + FILE_SPREAD_PAGE, + FILE_SPREAD_SLAB, +} cpuset_filetype_t; + +struct cpuset { + struct cgroup_subsys_state css; + + unsigned long flags; /* "unsigned long" so bitops work */ + + /* + * On default hierarchy: + * + * The user-configured masks can only be changed by writing to + * cpuset.cpus and cpuset.mems, and won't be limited by the + * parent masks. + * + * The effective masks is the real masks that apply to the tasks + * in the cpuset. They may be changed if the configured masks are + * changed or hotplug happens. + * + * effective_mask == configured_mask & parent's effective_mask, + * and if it ends up empty, it will inherit the parent's mask. + * + * + * On legacy hierarchy: + * + * The user-configured masks are always the same with effective masks. + */ + + /* user-configured CPUs and Memory Nodes allow to tasks */ + cpumask_var_t cpus_allowed; + nodemask_t mems_allowed; + + /* effective CPUs and Memory Nodes allow to tasks */ + cpumask_var_t effective_cpus; + nodemask_t effective_mems; + + /* + * Exclusive CPUs dedicated to current cgroup (default hierarchy only) + * + * The effective_cpus of a valid partition root comes solely from its + * effective_xcpus and some of the effective_xcpus may be distributed + * to sub-partitions below & hence excluded from its effective_cpus. + * For a valid partition root, its effective_cpus have no relationship + * with cpus_allowed unless its exclusive_cpus isn't set. + * + * This value will only be set if either exclusive_cpus is set or + * when this cpuset becomes a local partition root. + */ + cpumask_var_t effective_xcpus; + + /* + * Exclusive CPUs as requested by the user (default hierarchy only) + * + * Its value is independent of cpus_allowed and designates the set of + * CPUs that can be granted to the current cpuset or its children when + * it becomes a valid partition root. The effective set of exclusive + * CPUs granted (effective_xcpus) depends on whether those exclusive + * CPUs are passed down by its ancestors and not yet taken up by + * another sibling partition root along the way. + * + * If its value isn't set, it defaults to cpus_allowed. + */ + cpumask_var_t exclusive_cpus; + + /* + * This is old Memory Nodes tasks took on. + * + * - top_cpuset.old_mems_allowed is initialized to mems_allowed. + * - A new cpuset's old_mems_allowed is initialized when some + * task is moved into it. + * - old_mems_allowed is used in cpuset_migrate_mm() when we change + * cpuset.mems_allowed and have tasks' nodemask updated, and + * then old_mems_allowed is updated to mems_allowed. + */ + nodemask_t old_mems_allowed; + + struct fmeter fmeter; /* memory_pressure filter */ + + /* + * Tasks are being attached to this cpuset. Used to prevent + * zeroing cpus/mems_allowed between ->can_attach() and ->attach(). + */ + int attach_in_progress; + + /* for custom sched domain */ + int relax_domain_level; + + /* number of valid local child partitions */ + int nr_subparts; + + /* partition root state */ + int partition_root_state; + + /* + * number of SCHED_DEADLINE tasks attached to this cpuset, so that we + * know when to rebuild associated root domain bandwidth information. + */ + int nr_deadline_tasks; + int nr_migrate_dl_tasks; + u64 sum_migrate_dl_bw; + + /* Invalid partition error code, not lock protected */ + enum prs_errcode prs_err; + + /* Handle for cpuset.cpus.partition */ + struct cgroup_file partition_file; + + /* Remote partition silbling list anchored at remote_children */ + struct list_head remote_sibling; + + /* Used to merge intersecting subsets for generate_sched_domains */ + struct uf_node node; +}; + +static inline struct cpuset *css_cs(struct cgroup_subsys_state *css) +{ + return css ? container_of(css, struct cpuset, css) : NULL; +} + +/* Retrieve the cpuset for a task */ +static inline struct cpuset *task_cs(struct task_struct *task) +{ + return css_cs(task_css(task, cpuset_cgrp_id)); +} + +static inline struct cpuset *parent_cs(struct cpuset *cs) +{ + return css_cs(cs->css.parent); +} + +/* convenient tests for these bits */ +static inline bool is_cpuset_online(struct cpuset *cs) +{ + return test_bit(CS_ONLINE, &cs->flags) && !css_is_dying(&cs->css); +} + +static inline int is_cpu_exclusive(const struct cpuset *cs) +{ + return test_bit(CS_CPU_EXCLUSIVE, &cs->flags); +} + +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); +} + +static inline int is_memory_migrate(const struct cpuset *cs) +{ + return test_bit(CS_MEMORY_MIGRATE, &cs->flags); +} + +static inline int is_spread_page(const struct cpuset *cs) +{ + return test_bit(CS_SPREAD_PAGE, &cs->flags); +} + +static inline int is_spread_slab(const struct cpuset *cs) +{ + return test_bit(CS_SPREAD_SLAB, &cs->flags); +} + +/** + * cpuset_for_each_child - traverse online children of a cpuset + * @child_cs: loop cursor pointing to the current child + * @pos_css: used for iteration + * @parent_cs: target cpuset to walk children of + * + * Walk @child_cs through the online children of @parent_cs. Must be used + * with RCU read locked. + */ +#define cpuset_for_each_child(child_cs, pos_css, parent_cs) \ + css_for_each_child((pos_css), &(parent_cs)->css) \ + if (is_cpuset_online(((child_cs) = css_cs((pos_css))))) + +/** + * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants + * @des_cs: loop cursor pointing to the current descendant + * @pos_css: used for iteration + * @root_cs: target cpuset to walk ancestor of + * + * Walk @des_cs through the online descendants of @root_cs. Must be used + * with RCU read locked. The caller may modify @pos_css by calling + * css_rightmost_descendant() to skip subtree. @root_cs is included in the + * iteration and the first node to be visited. + */ +#define cpuset_for_each_descendant_pre(des_cs, pos_css, root_cs) \ + css_for_each_descendant_pre((pos_css), &(root_cs)->css) \ + if (is_cpuset_online(((des_cs) = css_cs((pos_css))))) + +void rebuild_sched_domains_locked(void); +void cpuset_callback_lock_irq(void); +void cpuset_callback_unlock_irq(void); +void cpuset_update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus); +void cpuset_update_tasks_nodemask(struct cpuset *cs); +int cpuset_update_flag(cpuset_flagbits_t bit, struct cpuset *cs, int turning_on); +ssize_t cpuset_write_resmask(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +int cpuset_common_seq_show(struct seq_file *sf, void *v); + +/* + * cpuset-v1.c + */ +#ifdef CONFIG_CPUSETS_V1 +extern struct cftype cpuset1_files[]; +void fmeter_init(struct fmeter *fmp); +void cpuset1_update_task_spread_flags(struct cpuset *cs, + struct task_struct *tsk); +void cpuset1_update_tasks_flags(struct cpuset *cs); +void cpuset1_hotplug_update_tasks(struct cpuset *cs, + struct cpumask *new_cpus, nodemask_t *new_mems, + bool cpus_updated, bool mems_updated); +int cpuset1_validate_change(struct cpuset *cur, struct cpuset *trial); +#else +static inline void fmeter_init(struct fmeter *fmp) {} +static inline void cpuset1_update_task_spread_flags(struct cpuset *cs, + struct task_struct *tsk) {} +static inline void cpuset1_update_tasks_flags(struct cpuset *cs) {} +static inline void cpuset1_hotplug_update_tasks(struct cpuset *cs, + struct cpumask *new_cpus, nodemask_t *new_mems, + bool cpus_updated, bool mems_updated) {} +static inline int cpuset1_validate_change(struct cpuset *cur, + struct cpuset *trial) { return 0; } +#endif /* CONFIG_CPUSETS_V1 */ + +#endif /* __CPUSET_INTERNAL_H */ diff --git a/kernel/cgroup/cpuset-v1.c b/kernel/cgroup/cpuset-v1.c new file mode 100644 index 000000000000..25c1d7b77e2f --- /dev/null +++ b/kernel/cgroup/cpuset-v1.c @@ -0,0 +1,562 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include "cpuset-internal.h" + +/* + * Legacy hierarchy call to cgroup_transfer_tasks() is handled asynchrously + */ +struct cpuset_remove_tasks_struct { + struct work_struct work; + struct cpuset *cs; +}; + +/* + * Frequency meter - How fast is some event occurring? + * + * These routines manage a digitally filtered, constant time based, + * event frequency meter. There are four routines: + * fmeter_init() - initialize a frequency meter. + * fmeter_markevent() - called each time the event happens. + * fmeter_getrate() - returns the recent rate of such events. + * fmeter_update() - internal routine used to update fmeter. + * + * A common data structure is passed to each of these routines, + * which is used to keep track of the state required to manage the + * frequency meter and its digital filter. + * + * The filter works on the number of events marked per unit time. + * The filter is single-pole low-pass recursive (IIR). The time unit + * is 1 second. Arithmetic is done using 32-bit integers scaled to + * simulate 3 decimal digits of precision (multiplied by 1000). + * + * With an FM_COEF of 933, and a time base of 1 second, the filter + * has a half-life of 10 seconds, meaning that if the events quit + * happening, then the rate returned from the fmeter_getrate() + * will be cut in half each 10 seconds, until it converges to zero. + * + * It is not worth doing a real infinitely recursive filter. If more + * than FM_MAXTICKS ticks have elapsed since the last filter event, + * just compute FM_MAXTICKS ticks worth, by which point the level + * will be stable. + * + * Limit the count of unprocessed events to FM_MAXCNT, so as to avoid + * arithmetic overflow in the fmeter_update() routine. + * + * Given the simple 32 bit integer arithmetic used, this meter works + * best for reporting rates between one per millisecond (msec) and + * one per 32 (approx) seconds. At constant rates faster than one + * per msec it maxes out at values just under 1,000,000. At constant + * rates between one per msec, and one per second it will stabilize + * to a value N*1000, where N is the rate of events per second. + * At constant rates between one per second and one per 32 seconds, + * it will be choppy, moving up on the seconds that have an event, + * and then decaying until the next event. At rates slower than + * about one in 32 seconds, it decays all the way back to zero between + * each event. + */ + +#define FM_COEF 933 /* coefficient for half-life of 10 secs */ +#define FM_MAXTICKS ((u32)99) /* useless computing more ticks than this */ +#define FM_MAXCNT 1000000 /* limit cnt to avoid overflow */ +#define FM_SCALE 1000 /* faux fixed point scale */ + +/* Initialize a frequency meter */ +void fmeter_init(struct fmeter *fmp) +{ + fmp->cnt = 0; + fmp->val = 0; + fmp->time = 0; + spin_lock_init(&fmp->lock); +} + +/* Internal meter update - process cnt events and update value */ +static void fmeter_update(struct fmeter *fmp) +{ + time64_t now; + u32 ticks; + + now = ktime_get_seconds(); + ticks = now - fmp->time; + + if (ticks == 0) + return; + + ticks = min(FM_MAXTICKS, ticks); + while (ticks-- > 0) + fmp->val = (FM_COEF * fmp->val) / FM_SCALE; + fmp->time = now; + + fmp->val += ((FM_SCALE - FM_COEF) * fmp->cnt) / FM_SCALE; + fmp->cnt = 0; +} + +/* Process any previous ticks, then bump cnt by one (times scale). */ +static void fmeter_markevent(struct fmeter *fmp) +{ + spin_lock(&fmp->lock); + fmeter_update(fmp); + fmp->cnt = min(FM_MAXCNT, fmp->cnt + FM_SCALE); + spin_unlock(&fmp->lock); +} + +/* Process any previous ticks, then return current value. */ +static int fmeter_getrate(struct fmeter *fmp) +{ + int val; + + spin_lock(&fmp->lock); + fmeter_update(fmp); + val = fmp->val; + spin_unlock(&fmp->lock); + return val; +} + +/* + * Collection of memory_pressure is suppressed unless + * this flag is enabled by writing "1" to the special + * cpuset file 'memory_pressure_enabled' in the root cpuset. + */ + +int cpuset_memory_pressure_enabled __read_mostly; + +/* + * __cpuset_memory_pressure_bump - keep stats of per-cpuset reclaims. + * + * Keep a running average of the rate of synchronous (direct) + * page reclaim efforts initiated by tasks in each cpuset. + * + * This represents the rate at which some task in the cpuset + * ran low on memory on all nodes it was allowed to use, and + * had to enter the kernels page reclaim code in an effort to + * create more free memory by tossing clean pages or swapping + * or writing dirty pages. + * + * Display to user space in the per-cpuset read-only file + * "memory_pressure". Value displayed is an integer + * representing the recent rate of entry into the synchronous + * (direct) page reclaim by any task attached to the cpuset. + */ + +void __cpuset_memory_pressure_bump(void) +{ + rcu_read_lock(); + fmeter_markevent(&task_cs(current)->fmeter); + rcu_read_unlock(); +} + +static int update_relax_domain_level(struct cpuset *cs, s64 val) +{ +#ifdef CONFIG_SMP + if (val < -1 || val > sched_domain_level_max + 1) + 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)) + rebuild_sched_domains_locked(); + } + + return 0; +} + +static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, + s64 val) +{ + struct cpuset *cs = css_cs(css); + cpuset_filetype_t type = cft->private; + int retval = -ENODEV; + + cpus_read_lock(); + cpuset_lock(); + if (!is_cpuset_online(cs)) + goto out_unlock; + + switch (type) { + case FILE_SCHED_RELAX_DOMAIN_LEVEL: + retval = update_relax_domain_level(cs, val); + break; + default: + retval = -EINVAL; + break; + } +out_unlock: + cpuset_unlock(); + cpus_read_unlock(); + return retval; +} + +static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft) +{ + struct cpuset *cs = css_cs(css); + cpuset_filetype_t type = cft->private; + + switch (type) { + case FILE_SCHED_RELAX_DOMAIN_LEVEL: + return cs->relax_domain_level; + default: + BUG(); + } + + /* Unreachable but makes gcc happy */ + return 0; +} + +/* + * update task's spread flag if cpuset's page/slab spread flag is set + * + * Call with callback_lock or cpuset_mutex held. The check can be skipped + * if on default hierarchy. + */ +void cpuset1_update_task_spread_flags(struct cpuset *cs, + struct task_struct *tsk) +{ + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) + return; + + if (is_spread_page(cs)) + task_set_spread_page(tsk); + else + task_clear_spread_page(tsk); + + if (is_spread_slab(cs)) + task_set_spread_slab(tsk); + else + task_clear_spread_slab(tsk); +} + +/** + * cpuset1_update_tasks_flags - update the spread flags of tasks in the cpuset. + * @cs: the cpuset in which each task's spread flags needs to be changed + * + * Iterate through each task of @cs updating its spread flags. As this + * function is called with cpuset_mutex held, cpuset membership stays + * stable. + */ +void cpuset1_update_tasks_flags(struct cpuset *cs) +{ + struct css_task_iter it; + struct task_struct *task; + + css_task_iter_start(&cs->css, 0, &it); + while ((task = css_task_iter_next(&it))) + cpuset1_update_task_spread_flags(cs, task); + css_task_iter_end(&it); +} + +/* + * 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. + */ +static void remove_tasks_in_empty_cpuset(struct cpuset *cs) +{ + struct cpuset *parent; + + /* + * Find its next-highest non-empty parent, (top cpuset + * has online cpus, so can't be empty). + */ + parent = parent_cs(cs); + while (cpumask_empty(parent->cpus_allowed) || + nodes_empty(parent->mems_allowed)) + parent = parent_cs(parent); + + if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { + pr_err("cpuset: failed to transfer tasks out of empty cpuset "); + pr_cont_cgroup_name(cs->css.cgroup); + pr_cont("\n"); + } +} + +static void cpuset_migrate_tasks_workfn(struct work_struct *work) +{ + struct cpuset_remove_tasks_struct *s; + + s = container_of(work, struct cpuset_remove_tasks_struct, work); + remove_tasks_in_empty_cpuset(s->cs); + css_put(&s->cs->css); + kfree(s); +} + +void cpuset1_hotplug_update_tasks(struct cpuset *cs, + struct cpumask *new_cpus, nodemask_t *new_mems, + bool cpus_updated, bool mems_updated) +{ + bool is_empty; + + cpuset_callback_lock_irq(); + cpumask_copy(cs->cpus_allowed, new_cpus); + cpumask_copy(cs->effective_cpus, new_cpus); + cs->mems_allowed = *new_mems; + cs->effective_mems = *new_mems; + cpuset_callback_unlock_irq(); + + /* + * Don't call cpuset_update_tasks_cpumask() if the cpuset becomes empty, + * as the tasks will be migrated to an ancestor. + */ + if (cpus_updated && !cpumask_empty(cs->cpus_allowed)) + cpuset_update_tasks_cpumask(cs, new_cpus); + if (mems_updated && !nodes_empty(cs->mems_allowed)) + cpuset_update_tasks_nodemask(cs); + + is_empty = cpumask_empty(cs->cpus_allowed) || + nodes_empty(cs->mems_allowed); + + /* + * Move tasks to the nearest ancestor with execution resources, + * This is full cgroup operation which will also call back into + * cpuset. Execute it asynchronously using workqueue. + */ + if (is_empty && cs->css.cgroup->nr_populated_csets && + css_tryget_online(&cs->css)) { + struct cpuset_remove_tasks_struct *s; + + s = kzalloc(sizeof(*s), GFP_KERNEL); + if (WARN_ON_ONCE(!s)) { + css_put(&cs->css); + return; + } + + s->cs = cs; + INIT_WORK(&s->work, cpuset_migrate_tasks_workfn); + schedule_work(&s->work); + } +} + +/* + * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q? + * + * 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 cpuset_mutex. + */ + +static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) +{ + 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); +} + +/* + * cpuset1_validate_change() - Validate conditions specific to legacy (v1) + * behavior. + */ +int cpuset1_validate_change(struct cpuset *cur, struct cpuset *trial) +{ + struct cgroup_subsys_state *css; + struct cpuset *c, *par; + int ret; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + /* Each of our child cpusets must be a subset of us */ + ret = -EBUSY; + cpuset_for_each_child(c, css, cur) + if (!is_cpuset_subset(c, trial)) + goto out; + + /* On legacy hierarchy, we must be a subset of our parent cpuset. */ + ret = -EACCES; + par = parent_cs(cur); + if (par && !is_cpuset_subset(trial, par)) + goto out; + + ret = 0; +out: + return ret; +} + +static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) +{ + struct cpuset *cs = css_cs(css); + 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 int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, + u64 val) +{ + struct cpuset *cs = css_cs(css); + cpuset_filetype_t type = cft->private; + int retval = 0; + + cpus_read_lock(); + cpuset_lock(); + if (!is_cpuset_online(cs)) { + retval = -ENODEV; + goto out_unlock; + } + + switch (type) { + case FILE_CPU_EXCLUSIVE: + retval = cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, val); + break; + case FILE_MEM_EXCLUSIVE: + retval = cpuset_update_flag(CS_MEM_EXCLUSIVE, cs, val); + break; + case FILE_MEM_HARDWALL: + retval = cpuset_update_flag(CS_MEM_HARDWALL, cs, val); + break; + case FILE_SCHED_LOAD_BALANCE: + retval = cpuset_update_flag(CS_SCHED_LOAD_BALANCE, cs, val); + break; + case FILE_MEMORY_MIGRATE: + retval = cpuset_update_flag(CS_MEMORY_MIGRATE, cs, val); + break; + case FILE_MEMORY_PRESSURE_ENABLED: + cpuset_memory_pressure_enabled = !!val; + break; + case FILE_SPREAD_PAGE: + retval = cpuset_update_flag(CS_SPREAD_PAGE, cs, val); + break; + case FILE_SPREAD_SLAB: + retval = cpuset_update_flag(CS_SPREAD_SLAB, cs, val); + break; + default: + retval = -EINVAL; + break; + } +out_unlock: + cpuset_unlock(); + cpus_read_unlock(); + return retval; +} + +/* + * for the common functions, 'private' gives the type of file + */ + +struct cftype cpuset1_files[] = { + { + .name = "cpus", + .seq_show = cpuset_common_seq_show, + .write = cpuset_write_resmask, + .max_write_len = (100U + 6 * NR_CPUS), + .private = FILE_CPULIST, + }, + + { + .name = "mems", + .seq_show = cpuset_common_seq_show, + .write = cpuset_write_resmask, + .max_write_len = (100U + 6 * MAX_NUMNODES), + .private = FILE_MEMLIST, + }, + + { + .name = "effective_cpus", + .seq_show = cpuset_common_seq_show, + .private = FILE_EFFECTIVE_CPULIST, + }, + + { + .name = "effective_mems", + .seq_show = cpuset_common_seq_show, + .private = FILE_EFFECTIVE_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, + .private = FILE_MEMORY_PRESSURE, + }, + + { + .name = "memory_spread_page", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SPREAD_PAGE, + }, + + { + /* obsolete, may be removed in the future */ + .name = "memory_spread_slab", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SPREAD_SLAB, + }, + + { + .name = "memory_pressure_enabled", + .flags = CFTYPE_ONLY_ON_ROOT, + .read_u64 = cpuset_read_u64, |