Systemd/src/basic/cgroup-util.h
Zbigniew Jędrzejewski-Szmek 3a0f06c41a core: make TasksMax a partially dynamic property
TasksMax= and DefaultTasksMax= can be specified as percentages. We don't
actually document of what the percentage is relative to, but the implementation
uses the smallest of /proc/sys/kernel/pid_max, /proc/sys/kernel/threads-max,
and /sys/fs/cgroup/pids.max (when present). When the value is a percentage,
we immediately convert it to an absolute value. If the limit later changes
(which can happen e.g. when systemd-sysctl runs), the absolute value becomes
outdated.

So let's store either the percentage or absolute value, whatever was specified,
and only convert to an absolute value when the value is used. For example, when
starting a unit, the absolute value will be calculated when the cgroup for
the unit is created.

Fixes #13419.
2019-11-14 18:41:54 +01:00

254 lines
9.7 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <dirent.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/statfs.h>
#include <sys/types.h>
#include "def.h"
#include "set.h"
#define SYSTEMD_CGROUP_CONTROLLER_LEGACY "name=systemd"
#define SYSTEMD_CGROUP_CONTROLLER_HYBRID "name=unified"
#define SYSTEMD_CGROUP_CONTROLLER "_systemd"
/* An enum of well known cgroup controllers */
typedef enum CGroupController {
/* Original cgroup controllers */
CGROUP_CONTROLLER_CPU,
CGROUP_CONTROLLER_CPUACCT, /* v1 only */
CGROUP_CONTROLLER_CPUSET, /* v2 only */
CGROUP_CONTROLLER_IO, /* v2 only */
CGROUP_CONTROLLER_BLKIO, /* v1 only */
CGROUP_CONTROLLER_MEMORY,
CGROUP_CONTROLLER_DEVICES, /* v1 only */
CGROUP_CONTROLLER_PIDS,
/* BPF-based pseudo-controllers, v2 only */
CGROUP_CONTROLLER_BPF_FIREWALL,
CGROUP_CONTROLLER_BPF_DEVICES,
_CGROUP_CONTROLLER_MAX,
_CGROUP_CONTROLLER_INVALID = -1,
} CGroupController;
#define CGROUP_CONTROLLER_TO_MASK(c) (1U << (c))
/* A bit mask of well known cgroup controllers */
typedef enum CGroupMask {
CGROUP_MASK_CPU = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_CPU),
CGROUP_MASK_CPUACCT = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_CPUACCT),
CGROUP_MASK_CPUSET = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_CPUSET),
CGROUP_MASK_IO = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_IO),
CGROUP_MASK_BLKIO = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BLKIO),
CGROUP_MASK_MEMORY = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_MEMORY),
CGROUP_MASK_DEVICES = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_DEVICES),
CGROUP_MASK_PIDS = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_PIDS),
CGROUP_MASK_BPF_FIREWALL = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BPF_FIREWALL),
CGROUP_MASK_BPF_DEVICES = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BPF_DEVICES),
/* All real cgroup v1 controllers */
CGROUP_MASK_V1 = CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT|CGROUP_MASK_BLKIO|CGROUP_MASK_MEMORY|CGROUP_MASK_DEVICES|CGROUP_MASK_PIDS,
/* All real cgroup v2 controllers */
CGROUP_MASK_V2 = CGROUP_MASK_CPU|CGROUP_MASK_CPUSET|CGROUP_MASK_IO|CGROUP_MASK_MEMORY|CGROUP_MASK_PIDS,
/* All cgroup v2 BPF pseudo-controllers */
CGROUP_MASK_BPF = CGROUP_MASK_BPF_FIREWALL|CGROUP_MASK_BPF_DEVICES,
_CGROUP_MASK_ALL = CGROUP_CONTROLLER_TO_MASK(_CGROUP_CONTROLLER_MAX) - 1
} CGroupMask;
static inline CGroupMask CGROUP_MASK_EXTEND_JOINED(CGroupMask mask) {
/* We always mount "cpu" and "cpuacct" in the same hierarchy. Hence, when one bit is set also set the other */
if (mask & (CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT))
mask |= (CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT);
return mask;
}
CGroupMask get_cpu_accounting_mask(void);
bool cpu_accounting_is_cheap(void);
/* Special values for all weight knobs on unified hierarchy */
#define CGROUP_WEIGHT_INVALID ((uint64_t) -1)
#define CGROUP_WEIGHT_MIN UINT64_C(1)
#define CGROUP_WEIGHT_MAX UINT64_C(10000)
#define CGROUP_WEIGHT_DEFAULT UINT64_C(100)
#define CGROUP_LIMIT_MIN UINT64_C(0)
#define CGROUP_LIMIT_MAX ((uint64_t) -1)
static inline bool CGROUP_WEIGHT_IS_OK(uint64_t x) {
return
x == CGROUP_WEIGHT_INVALID ||
(x >= CGROUP_WEIGHT_MIN && x <= CGROUP_WEIGHT_MAX);
}
/* IO limits on unified hierarchy */
typedef enum CGroupIOLimitType {
CGROUP_IO_RBPS_MAX,
CGROUP_IO_WBPS_MAX,
CGROUP_IO_RIOPS_MAX,
CGROUP_IO_WIOPS_MAX,
_CGROUP_IO_LIMIT_TYPE_MAX,
_CGROUP_IO_LIMIT_TYPE_INVALID = -1
} CGroupIOLimitType;
extern const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX];
const char* cgroup_io_limit_type_to_string(CGroupIOLimitType t) _const_;
CGroupIOLimitType cgroup_io_limit_type_from_string(const char *s) _pure_;
/* Special values for the cpu.shares attribute */
#define CGROUP_CPU_SHARES_INVALID ((uint64_t) -1)
#define CGROUP_CPU_SHARES_MIN UINT64_C(2)
#define CGROUP_CPU_SHARES_MAX UINT64_C(262144)
#define CGROUP_CPU_SHARES_DEFAULT UINT64_C(1024)
static inline bool CGROUP_CPU_SHARES_IS_OK(uint64_t x) {
return
x == CGROUP_CPU_SHARES_INVALID ||
(x >= CGROUP_CPU_SHARES_MIN && x <= CGROUP_CPU_SHARES_MAX);
}
/* Special values for the blkio.weight attribute */
#define CGROUP_BLKIO_WEIGHT_INVALID ((uint64_t) -1)
#define CGROUP_BLKIO_WEIGHT_MIN UINT64_C(10)
#define CGROUP_BLKIO_WEIGHT_MAX UINT64_C(1000)
#define CGROUP_BLKIO_WEIGHT_DEFAULT UINT64_C(500)
static inline bool CGROUP_BLKIO_WEIGHT_IS_OK(uint64_t x) {
return
x == CGROUP_BLKIO_WEIGHT_INVALID ||
(x >= CGROUP_BLKIO_WEIGHT_MIN && x <= CGROUP_BLKIO_WEIGHT_MAX);
}
/* Default resource limits */
#define DEFAULT_USER_TASKS_MAX_PERCENTAGE 33U /* 33% of PIDs, 10813 on default settings */
typedef enum CGroupUnified {
CGROUP_UNIFIED_UNKNOWN = -1,
CGROUP_UNIFIED_NONE = 0, /* Both systemd and controllers on legacy */
CGROUP_UNIFIED_SYSTEMD = 1, /* Only systemd on unified */
CGROUP_UNIFIED_ALL = 2, /* Both systemd and controllers on unified */
} CGroupUnified;
/*
* General rules:
*
* We accept named hierarchies in the syntax "foo" and "name=foo".
*
* We expect that named hierarchies do not conflict in name with a
* kernel hierarchy, modulo the "name=" prefix.
*
* We always generate "normalized" controller names, i.e. without the
* "name=" prefix.
*
* We require absolute cgroup paths. When returning, we will always
* generate paths with multiple adjacent / removed.
*/
int cg_enumerate_processes(const char *controller, const char *path, FILE **_f);
int cg_read_pid(FILE *f, pid_t *_pid);
int cg_read_event(const char *controller, const char *path, const char *event,
char **val);
int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d);
int cg_read_subgroup(DIR *d, char **fn);
typedef enum CGroupFlags {
CGROUP_SIGCONT = 1 << 0,
CGROUP_IGNORE_SELF = 1 << 1,
CGROUP_REMOVE = 1 << 2,
} CGroupFlags;
typedef int (*cg_kill_log_func_t)(pid_t pid, int sig, void *userdata);
int cg_kill(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_kill_recursive(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_split_spec(const char *spec, char **controller, char **path);
int cg_mangle_path(const char *path, char **result);
int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs);
int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs);
int cg_pid_get_path(const char *controller, pid_t pid, char **path);
int cg_rmdir(const char *controller, const char *path);
int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value);
int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret);
int cg_get_keyed_attribute(const char *controller, const char *path, const char *attribute, char **keys, char **values);
int cg_set_access(const char *controller, const char *path, uid_t uid, gid_t gid);
int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags);
int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size);
int cg_install_release_agent(const char *controller, const char *agent);
int cg_uninstall_release_agent(const char *controller);
int cg_is_empty(const char *controller, const char *path);
int cg_is_empty_recursive(const char *controller, const char *path);
int cg_get_root_path(char **path);
int cg_path_get_session(const char *path, char **session);
int cg_path_get_owner_uid(const char *path, uid_t *uid);
int cg_path_get_unit(const char *path, char **unit);
int cg_path_get_user_unit(const char *path, char **unit);
int cg_path_get_machine_name(const char *path, char **machine);
int cg_path_get_slice(const char *path, char **slice);
int cg_path_get_user_slice(const char *path, char **slice);
int cg_shift_path(const char *cgroup, const char *cached_root, const char **shifted);
int cg_pid_get_path_shifted(pid_t pid, const char *cached_root, char **cgroup);
int cg_pid_get_session(pid_t pid, char **session);
int cg_pid_get_owner_uid(pid_t pid, uid_t *uid);
int cg_pid_get_unit(pid_t pid, char **unit);
int cg_pid_get_user_unit(pid_t pid, char **unit);
int cg_pid_get_machine_name(pid_t pid, char **machine);
int cg_pid_get_slice(pid_t pid, char **slice);
int cg_pid_get_user_slice(pid_t pid, char **slice);
int cg_path_decode_unit(const char *cgroup, char **unit);
char *cg_escape(const char *p);
char *cg_unescape(const char *p) _pure_;
bool cg_controller_is_valid(const char *p);
int cg_slice_to_path(const char *unit, char **ret);
typedef const char* (*cg_migrate_callback_t)(CGroupMask mask, void *userdata);
int cg_mask_supported(CGroupMask *ret);
int cg_mask_from_string(const char *s, CGroupMask *ret);
int cg_mask_to_string(CGroupMask mask, char **ret);
int cg_kernel_controllers(Set **controllers);
bool cg_ns_supported(void);
int cg_all_unified(void);
int cg_hybrid_unified(void);
int cg_unified_controller(const char *controller);
int cg_unified_cached(bool flush);
static inline int cg_unified(void) {
return cg_unified_cached(true);
}
const char* cgroup_controller_to_string(CGroupController c) _const_;
CGroupController cgroup_controller_from_string(const char *s) _pure_;
bool is_cgroup_fs(const struct statfs *s);
bool fd_is_cgroup_fs(int fd);