15263807472

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <unistd.h>

#include "alloc-util.h"
#include "cgroup-util.h"
#include "limits-util.h"
#include "log.h"
#include "memory-util.h"
#include "parse-util.h"
#include "process-util.h"
#include "procfs-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 32-bit process on a 64-bit 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 == -ENOENT) /* Field does not exist on the system's top-level cgroup, hence don't
                                   * complain. (Note that it might exist on our own root though, if we live
                                   * in a cgroup namespace, hence check anyway instead of not even
                                   * trying.) */
                        return mem;
                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;

        /* Shortcut two special cases */
        if (v == 0)
                return 0;
        if (v == max)
                return physical_memory();

        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);

        if (v > UINT64_MAX / p)
                return UINT64_MAX;

        m = p * v;
        m /= max;

        if (m > UINT64_MAX / ps)
                return UINT64_MAX;

        return m * ps;
}

uint64_t system_tasks_max(void) {
        uint64_t a = TASKS_MAX, b = TASKS_MAX, c = 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) kernel.threads-max sysctl: the maximum number of tasks (threads) the kernel allows.
         *
         *    This puts a direct limit on the number of concurrent tasks.
         *
         * b) kernel.pid_max sysctl: the maximum PID value.
         *
         *    This limits the numeric range PIDs can take, and thus indirectly also limits the number of
         *    concurrent threads. It's primarily a compatibility concept: some crappy old code used a signed
         *    16-bit type for PIDs, hence the kernel provides a way to ensure the PIDs never go beyond
         *    INT16_MAX by default.
         *
         *    Also note the weird definition: PIDs assigned will be kept below this value, which means
         *    the number of tasks that can be created is one lower, as PID 0 is not a valid process ID.
         *
         * c) pids.max on the root cgroup: the kernel's configured maximum number of tasks.
         *
         * and then pick the smallest of the three.
         *
         * By default pid_max is set to much lower values than threads-max, hence the limit people come into
         * contact with first, as it's the lowest boundary they need to bump when they want higher number of
         * processes.
         */

        r = procfs_get_threads_max(&a);
        if (r < 0)
                log_debug_errno(r, "Failed to read kernel.threads-max, ignoring: %m");

        r = procfs_get_pid_max(&b);
        if (r < 0)
                log_debug_errno(r, "Failed to read kernel.pid_max, ignoring: %m");
        else if (b > 0)
                /* Subtract one from pid_max, since PID 0 is not a valid PID */
                b--;

        r = cg_get_root_path(&root);
        if (r < 0)
                log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m");
        else {
                /* We'll have the "pids.max" attribute on the our root cgroup only if we are in a
                 * CLONE_NEWCGROUP namespace. On the top-level namespace this attribute is missing, hence
                 * suppress any message about that */
                r = cg_get_attribute_as_uint64("pids", root, "pids.max", &c);
                if (r < 0 && r != -ENODATA)
                        log_debug_errno(r, "Failed to read pids.max attribute of root cgroup, ignoring: %m");
        }

        return MIN3(a, b, c);
}

uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) {
        uint64_t t, m;

        /* Shortcut two special cases */
        if (v == 0)
                return 0;
        if (v == max)
                return system_tasks_max();

        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);

        if (v > UINT64_MAX / t) /* overflow? */
                return UINT64_MAX;

        m = t * v;
        return m / max;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <unistd.h>
4
5	#include "alloc-util.h"
6	#include "cgroup-util.h"
7	#include "limits-util.h"
8	#include "log.h"
9	#include "memory-util.h"
10	#include "parse-util.h"
11	#include "process-util.h"
12	#include "procfs-util.h"
13
14	uint64_t physical_memory(void) {	4,457✔
15	_cleanup_free_ char root = NULL, value = NULL;	4,457✔
16	uint64_t mem, lim;	4,457✔
17	size_t ps;	4,457✔
18	long sc;	4,457✔
19	int r;	4,457✔
20
21	/* We return this as uint64_t in case we are running as 32-bit process on a 64-bit kernel with huge amounts of
22	* memory.
23	*
24	* In order to support containers nicely that have a configured memory limit we'll take the minimum of the
25	* physically reported amount of memory and the limit configured for the root cgroup, if there is any. */
26
27	sc = sysconf(_SC_PHYS_PAGES);	4,457✔
28	assert(sc > 0);	4,457✔
29
30	ps = page_size();	4,457✔
31	mem = (uint64_t) sc * (uint64_t) ps;	4,457✔
32
33	r = cg_get_root_path(&root);	4,457✔
34	if (r < 0) {	4,457✔
UNCOV 35	log_debug_errno(r, "Failed to determine root cgroup, ignoring cgroup memory limit: %m");	×
36	return mem;	×
37	}
38
39	r = cg_all_unified();	4,457✔
40	if (r < 0) {	4,457✔
UNCOV 41	log_debug_errno(r, "Failed to determine root unified mode, ignoring cgroup memory limit: %m");	×
42	return mem;	×
43	}
44	if (r > 0) {	4,457✔
45	r = cg_get_attribute("memory", root, "memory.max", &value);	4,457✔
46	if (r == -ENOENT) /* Field does not exist on the system's top-level cgroup, hence don't	4,457✔
47	* complain. (Note that it might exist on our own root though, if we live
48	* in a cgroup namespace, hence check anyway instead of not even
49	* trying.) */
50	return mem;
51	if (r < 0) {	3,767✔
UNCOV 52	log_debug_errno(r, "Failed to read memory.max cgroup attribute, ignoring cgroup memory limit: %m");	×
53	return mem;	×
54	}
55
56	if (streq(value, "max"))	3,767✔
57	return mem;
58	} else {
UNCOV 59	r = cg_get_attribute("memory", root, "memory.limit_in_bytes", &value);	×
60	if (r < 0) {	×
61	log_debug_errno(r, "Failed to read memory.limit_in_bytes cgroup attribute, ignoring cgroup memory limit: %m");	×
62	return mem;	×
63	}
64	}
65
UNCOV 66	r = safe_atou64(value, &lim);	×
67	if (r < 0) {	×
68	log_debug_errno(r, "Failed to parse cgroup memory limit '%s', ignoring: %m", value);	×
69	return mem;	×
70	}
UNCOV 71	if (lim == UINT64_MAX)	×
72	return mem;
73
74	/* Make sure the limit is a multiple of our own page size */
UNCOV 75	lim /= ps;	×
76	lim *= ps;	×
77
UNCOV 78	return MIN(mem, lim);	×
79	}
80
81	uint64_t physical_memory_scale(uint64_t v, uint64_t max) {	357✔
82	uint64_t p, m, ps;	357✔
83
84	/* Shortcut two special cases */
85	if (v == 0)	357✔
86	return 0;
87	if (v == max)	353✔
88	return physical_memory();	4✔
89
90	assert(max > 0);	349✔
91
92	/* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success
93	* the result is a multiple of the page size (rounds down). */
94
95	ps = page_size();	349✔
96	assert(ps > 0);	349✔
97
98	p = physical_memory() / ps;	349✔
99	assert(p > 0);	349✔
100
101	if (v > UINT64_MAX / p)	349✔
102	return UINT64_MAX;
103
104	m = p * v;	348✔
105	m /= max;	348✔
106
107	if (m > UINT64_MAX / ps)	348✔
108	return UINT64_MAX;
109
110	return m * ps;	348✔
111	}
112
113	uint64_t system_tasks_max(void) {	6,910✔
114	uint64_t a = TASKS_MAX, b = TASKS_MAX, c = TASKS_MAX;	6,910✔
115	_cleanup_free_ char *root = NULL;	6,910✔
116	int r;	6,910✔
117
118	/* Determine the maximum number of tasks that may run on this system. We check three sources to
119	* determine this limit:
120	*
121	* a) kernel.threads-max sysctl: the maximum number of tasks (threads) the kernel allows.
122	*
123	* This puts a direct limit on the number of concurrent tasks.
124	*
125	* b) kernel.pid_max sysctl: the maximum PID value.
126	*
127	* This limits the numeric range PIDs can take, and thus indirectly also limits the number of
128	* concurrent threads. It's primarily a compatibility concept: some crappy old code used a signed
129	* 16-bit type for PIDs, hence the kernel provides a way to ensure the PIDs never go beyond
130	* INT16_MAX by default.
131	*
132	* Also note the weird definition: PIDs assigned will be kept below this value, which means
133	* the number of tasks that can be created is one lower, as PID 0 is not a valid process ID.
134	*
135	* c) pids.max on the root cgroup: the kernel's configured maximum number of tasks.
136	*
137	* and then pick the smallest of the three.
138	*
139	* By default pid_max is set to much lower values than threads-max, hence the limit people come into
140	* contact with first, as it's the lowest boundary they need to bump when they want higher number of
141	* processes.
142	*/
143
144	r = procfs_get_threads_max(&a);	6,910✔
145	if (r < 0)	6,910✔
UNCOV 146	log_debug_errno(r, "Failed to read kernel.threads-max, ignoring: %m");	×
147
148	r = procfs_get_pid_max(&b);	6,910✔
149	if (r < 0)	6,910✔
UNCOV 150	log_debug_errno(r, "Failed to read kernel.pid_max, ignoring: %m");	×
151	else if (b > 0)	6,910✔
152	/* Subtract one from pid_max, since PID 0 is not a valid PID */
153	b--;	6,910✔
154
155	r = cg_get_root_path(&root);	6,910✔
156	if (r < 0)	6,910✔
UNCOV 157	log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m");	×
158	else {
159	/* We'll have the "pids.max" attribute on the our root cgroup only if we are in a
160	* CLONE_NEWCGROUP namespace. On the top-level namespace this attribute is missing, hence
161	* suppress any message about that */
162	r = cg_get_attribute_as_uint64("pids", root, "pids.max", &c);	6,910✔
163	if (r < 0 && r != -ENODATA)	6,910✔
UNCOV 164	log_debug_errno(r, "Failed to read pids.max attribute of root cgroup, ignoring: %m");	×
165	}
166
167	return MIN3(a, b, c);	6,910✔
168	}
169
170	uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) {	5,576✔
171	uint64_t t, m;	5,576✔
172
173	/* Shortcut two special cases */
174	if (v == 0)	5,576✔
175	return 0;
176	if (v == max)	5,572✔
177	return system_tasks_max();	4✔
178
179	assert(max > 0);	5,568✔
180
181	/* Multiply the system's task value by the fraction v/max. Hence, if max==100 this calculates percentages
182	* relative to the system's maximum number of tasks. Returns UINT64_MAX on overflow. */
183
184	t = system_tasks_max();	5,568✔
185	assert(t > 0);	5,568✔
186
187	if (v > UINT64_MAX / t) /* overflow? */	5,568✔
188	return UINT64_MAX;
189
190	m = t * v;	5,567✔
191	return m / max;	5,567✔
192	}

systemd / systemd / 15263807472

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