include/linux/threads.h

   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 that can run under SMP.  This value is
  12  * set via configure setting.  The maximum is equal to the size of the
  13  * bitmasks used on that platform, i.e. 32 or 64.  Setting this smaller
  14  * saves quite a bit of memory.
  15  */
  16 #ifdef CONFIG_SMP
  17 #define NR_CPUS         CONFIG_NR_CPUS
  18 #else
  19 #define NR_CPUS         1
  20 #endif
  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 #endif