1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_THREADS_H
3 #define _LINUX_THREADS_H
7 * The default limit for the nr of threads is now in
8 * /proc/sys/kernel/threads-max.
12 * Maximum supported processors. Setting this smaller saves quite a
13 * bit of memory. Use nr_cpu_ids instead of this except for static bitmaps.
15 #ifndef CONFIG_NR_CPUS
16 /* FIXME: This should be fixed in the arch's Kconfig */
17 #define CONFIG_NR_CPUS 1
20 /* Places which use this should consider cpumask_var_t. */
21 #define NR_CPUS CONFIG_NR_CPUS
23 #define MIN_THREADS_LEFT_FOR_ROOT 4
26 * This controls the default maximum pid allocated to a process
28 #define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
31 * A maximum of 4 million PIDs should be enough for a while.
32 * [NOTE: PID/TIDs are limited to 2^29 ~= 500+ million, see futex.h.]
34 #define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
35 (sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
38 * Define a minimum number of pids per cpu. Heuristically based
39 * on original pid max of 32k for 32 cpus. Also, increase the
40 * minimum settable value for pid_max on the running system based
41 * on similar defaults. See kernel/pid.c:pidmap_init() for details.
43 #define PIDS_PER_CPU_DEFAULT 1024
44 #define PIDS_PER_CPU_MIN 8