util: split out some stuff into a new file limits-util.[ch]

This commit is contained in:
Lennart Poettering 2019-03-13 11:35:47 +01:00
parent 0cb8e3d118
commit eefc66aa8f
12 changed files with 175 additions and 154 deletions

156
src/basic/limits-util.c Normal file
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@ -0,0 +1,156 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#include "alloc-util.h"
#include "cgroup-util.h"
#include "limits-util.h"
#include "parse-util.h"
#include "process-util.h"
#include "procfs-util.h"
#include "string-util.h"
uint64_t physical_memory(void) {
_cleanup_free_ char *root = NULL, *value = NULL;
uint64_t mem, lim;
size_t ps;
long sc;
int r;
/* We return this as uint64_t in case we are running as 32bit process on a 64bit kernel with huge amounts of
* memory.
*
* In order to support containers nicely that have a configured memory limit we'll take the minimum of the
* physically reported amount of memory and the limit configured for the root cgroup, if there is any. */
sc = sysconf(_SC_PHYS_PAGES);
assert(sc > 0);
ps = page_size();
mem = (uint64_t) sc * (uint64_t) ps;
r = cg_get_root_path(&root);
if (r < 0) {
log_debug_errno(r, "Failed to determine root cgroup, ignoring cgroup memory limit: %m");
return mem;
}
r = cg_all_unified();
if (r < 0) {
log_debug_errno(r, "Failed to determine root unified mode, ignoring cgroup memory limit: %m");
return mem;
}
if (r > 0) {
r = cg_get_attribute("memory", root, "memory.max", &value);
if (r < 0) {
log_debug_errno(r, "Failed to read memory.max cgroup attribute, ignoring cgroup memory limit: %m");
return mem;
}
if (streq(value, "max"))
return mem;
} else {
r = cg_get_attribute("memory", root, "memory.limit_in_bytes", &value);
if (r < 0) {
log_debug_errno(r, "Failed to read memory.limit_in_bytes cgroup attribute, ignoring cgroup memory limit: %m");
return mem;
}
}
r = safe_atou64(value, &lim);
if (r < 0) {
log_debug_errno(r, "Failed to parse cgroup memory limit '%s', ignoring: %m", value);
return mem;
}
if (lim == UINT64_MAX)
return mem;
/* Make sure the limit is a multiple of our own page size */
lim /= ps;
lim *= ps;
return MIN(mem, lim);
}
uint64_t physical_memory_scale(uint64_t v, uint64_t max) {
uint64_t p, m, ps, r;
assert(max > 0);
/* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success
* the result is a multiple of the page size (rounds down). */
ps = page_size();
assert(ps > 0);
p = physical_memory() / ps;
assert(p > 0);
m = p * v;
if (m / p != v)
return UINT64_MAX;
m /= max;
r = m * ps;
if (r / ps != m)
return UINT64_MAX;
return r;
}
uint64_t system_tasks_max(void) {
uint64_t a = TASKS_MAX, b = TASKS_MAX;
_cleanup_free_ char *root = NULL;
int r;
/* Determine the maximum number of tasks that may run on this system. We check three sources to determine this
* limit:
*
* a) the maximum tasks value the kernel allows on this architecture
* b) the cgroups pids_max attribute for the system
* c) the kernel's configured maximum PID value
*
* And then pick the smallest of the three */
r = procfs_tasks_get_limit(&a);
if (r < 0)
log_debug_errno(r, "Failed to read maximum number of tasks from /proc, ignoring: %m");
r = cg_get_root_path(&root);
if (r < 0)
log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m");
else {
_cleanup_free_ char *value = NULL;
r = cg_get_attribute("pids", root, "pids.max", &value);
if (r < 0)
log_debug_errno(r, "Failed to read pids.max attribute of cgroup root, ignoring: %m");
else if (!streq(value, "max")) {
r = safe_atou64(value, &b);
if (r < 0)
log_debug_errno(r, "Failed to parse pids.max attribute of cgroup root, ignoring: %m");
}
}
return MIN3(TASKS_MAX,
a <= 0 ? TASKS_MAX : a,
b <= 0 ? TASKS_MAX : b);
}
uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) {
uint64_t t, m;
assert(max > 0);
/* Multiply the system's task value by the fraction v/max. Hence, if max==100 this calculates percentages
* relative to the system's maximum number of tasks. Returns UINT64_MAX on overflow. */
t = system_tasks_max();
assert(t > 0);
m = t * v;
if (m / t != v) /* overflow? */
return UINT64_MAX;
return m / max;
}

10
src/basic/limits-util.h Normal file
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@ -0,0 +1,10 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <inttypes.h>
uint64_t physical_memory(void);
uint64_t physical_memory_scale(uint64_t v, uint64_t max);
uint64_t system_tasks_max(void);
uint64_t system_tasks_max_scale(uint64_t v, uint64_t max);

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@ -79,6 +79,8 @@ basic_sources = files('''
khash.h
label.c
label.h
limits-util.c
limits-util.h
list.h
locale-util.c
locale-util.h

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@ -19,7 +19,6 @@
#include "alloc-util.h"
#include "btrfs-util.h"
#include "build.h"
#include "cgroup-util.h"
#include "def.h"
#include "device-nodes.h"
#include "dirent-util.h"
@ -294,153 +293,6 @@ int container_get_leader(const char *machine, pid_t *pid) {
return 0;
}
uint64_t physical_memory(void) {
_cleanup_free_ char *root = NULL, *value = NULL;
uint64_t mem, lim;
size_t ps;
long sc;
int r;
/* We return this as uint64_t in case we are running as 32bit process on a 64bit kernel with huge amounts of
* memory.
*
* In order to support containers nicely that have a configured memory limit we'll take the minimum of the
* physically reported amount of memory and the limit configured for the root cgroup, if there is any. */
sc = sysconf(_SC_PHYS_PAGES);
assert(sc > 0);
ps = page_size();
mem = (uint64_t) sc * (uint64_t) ps;
r = cg_get_root_path(&root);
if (r < 0) {
log_debug_errno(r, "Failed to determine root cgroup, ignoring cgroup memory limit: %m");
return mem;
}
r = cg_all_unified();
if (r < 0) {
log_debug_errno(r, "Failed to determine root unified mode, ignoring cgroup memory limit: %m");
return mem;
}
if (r > 0) {
r = cg_get_attribute("memory", root, "memory.max", &value);
if (r < 0) {
log_debug_errno(r, "Failed to read memory.max cgroup attribute, ignoring cgroup memory limit: %m");
return mem;
}
if (streq(value, "max"))
return mem;
} else {
r = cg_get_attribute("memory", root, "memory.limit_in_bytes", &value);
if (r < 0) {
log_debug_errno(r, "Failed to read memory.limit_in_bytes cgroup attribute, ignoring cgroup memory limit: %m");
return mem;
}
}
r = safe_atou64(value, &lim);
if (r < 0) {
log_debug_errno(r, "Failed to parse cgroup memory limit '%s', ignoring: %m", value);
return mem;
}
if (lim == UINT64_MAX)
return mem;
/* Make sure the limit is a multiple of our own page size */
lim /= ps;
lim *= ps;
return MIN(mem, lim);
}
uint64_t physical_memory_scale(uint64_t v, uint64_t max) {
uint64_t p, m, ps, r;
assert(max > 0);
/* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success
* the result is a multiple of the page size (rounds down). */
ps = page_size();
assert(ps > 0);
p = physical_memory() / ps;
assert(p > 0);
m = p * v;
if (m / p != v)
return UINT64_MAX;
m /= max;
r = m * ps;
if (r / ps != m)
return UINT64_MAX;
return r;
}
uint64_t system_tasks_max(void) {
uint64_t a = TASKS_MAX, b = TASKS_MAX;
_cleanup_free_ char *root = NULL;
int r;
/* Determine the maximum number of tasks that may run on this system. We check three sources to determine this
* limit:
*
* a) the maximum tasks value the kernel allows on this architecture
* b) the cgroups pids_max attribute for the system
* c) the kernel's configured maximum PID value
*
* And then pick the smallest of the three */
r = procfs_tasks_get_limit(&a);
if (r < 0)
log_debug_errno(r, "Failed to read maximum number of tasks from /proc, ignoring: %m");
r = cg_get_root_path(&root);
if (r < 0)
log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m");
else {
_cleanup_free_ char *value = NULL;
r = cg_get_attribute("pids", root, "pids.max", &value);
if (r < 0)
log_debug_errno(r, "Failed to read pids.max attribute of cgroup root, ignoring: %m");
else if (!streq(value, "max")) {
r = safe_atou64(value, &b);
if (r < 0)
log_debug_errno(r, "Failed to parse pids.max attribute of cgroup root, ignoring: %m");
}
}
return MIN3(TASKS_MAX,
a <= 0 ? TASKS_MAX : a,
b <= 0 ? TASKS_MAX : b);
}
uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) {
uint64_t t, m;
assert(max > 0);
/* Multiply the system's task value by the fraction v/max. Hence, if max==100 this calculates percentages
* relative to the system's maximum number of tasks. Returns UINT64_MAX on overflow. */
t = system_tasks_max();
assert(t > 0);
m = t * v;
if (m / t != v) /* overflow? */
return UINT64_MAX;
return m / max;
}
int version(void) {
puts("systemd " STRINGIFY(PROJECT_VERSION) " (" GIT_VERSION ")\n"
SYSTEMD_FEATURES);

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@ -237,12 +237,6 @@ static inline unsigned log2u_round_up(unsigned x) {
int container_get_leader(const char *machine, pid_t *pid);
uint64_t physical_memory(void);
uint64_t physical_memory_scale(uint64_t v, uint64_t max);
uint64_t system_tasks_max(void);
uint64_t system_tasks_max_scale(uint64_t v, uint64_t max);
int version(void);
int str_verscmp(const char *s1, const char *s2);

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@ -13,6 +13,7 @@
#include "dbus-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "limits-util.h"
#include "path-util.h"
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_cgroup_device_policy, cgroup_device_policy, CGroupDevicePolicy);

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@ -36,6 +36,7 @@
#include "ioprio.h"
#include "ip-protocol-list.h"
#include "journal-util.h"
#include "limits-util.h"
#include "load-fragment.h"
#include "log.h"
#include "missing.h"

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@ -47,6 +47,7 @@
#include "ima-setup.h"
#include "killall.h"
#include "kmod-setup.h"
#include "limits-util.h"
#include "load-fragment.h"
#include "log.h"
#include "loopback-setup.h"

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@ -18,6 +18,7 @@
#include "conf-parser.h"
#include "device-util.h"
#include "fd-util.h"
#include "limits-util.h"
#include "logind.h"
#include "parse-util.h"
#include "path-util.h"

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@ -19,6 +19,7 @@
#include "fs-util.h"
#include "hashmap.h"
#include "label.h"
#include "limits-util.h"
#include "logind-user.h"
#include "mkdir.h"
#include "parse-util.h"

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@ -8,6 +8,7 @@
#include "def.h"
#include "fileio.h"
#include "fs-util.h"
#include "limits-util.h"
#include "missing_syscall.h"
#include "parse-util.h"
#include "process-util.h"

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@ -46,6 +46,7 @@
#include "hashmap.h"
#include "io-util.h"
#include "libudev-device-internal.h"
#include "limits-util.h"
#include "list.h"
#include "main-func.h"
#include "mkdir.h"