linux/include/linux/threads.h
<<
>>
Prefs
   1#ifndef _LINUX_THREADS_H
   2#define _LINUX_THREADS_H
   3
   4
   5/*
   6 * The default limit for the nr of threads is now in
   7 * /proc/sys/kernel/threads-max.
   8 */
   9
  10/*
  11 * Maximum supported processors.  Setting this smaller saves quite a
  12 * bit of memory.  Use nr_cpu_ids instead of this except for static bitmaps.
  13 */
  14#ifndef CONFIG_NR_CPUS
  15/* FIXME: This should be fixed in the arch's Kconfig */
  16#define CONFIG_NR_CPUS  1
  17#endif
  18
  19/* Places which use this should consider cpumask_var_t. */
  20#define NR_CPUS         CONFIG_NR_CPUS
  21
  22#define MIN_THREADS_LEFT_FOR_ROOT 4
  23
  24/*
  25 * This controls the default maximum pid allocated to a process
  26 */
  27#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
  28
  29/*
  30 * A maximum of 4 million PIDs should be enough for a while.
  31 * [NOTE: PID/TIDs are limited to 2^29 ~= 500+ million, see futex.h.]
  32 */
  33#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
  34        (sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
  35
  36/*
  37 * Define a minimum number of pids per cpu.  Heuristically based
  38 * on original pid max of 32k for 32 cpus.  Also, increase the
  39 * minimum settable value for pid_max on the running system based
  40 * on similar defaults.  See kernel/pid.c:pidmap_init() for details.
  41 */
  42#define PIDS_PER_CPU_DEFAULT    1024
  43#define PIDS_PER_CPU_MIN        8
  44
  45#endif
  46