include/linux/threads.h

   1 #ifndef _LINUX_THREADS_H
   2 #define _LINUX_THREADS_H
   3
   4 #include <linux/config.h>
   5
   6 /*
   7  * The default limit for the nr of threads is now in
   8  * /proc/sys/kernel/threads-max.
   9  */
  10
  11 /*
  12  * Maximum supported processors that can run under SMP.  This value is
  13  * set via configure setting.  The maximum is equal to the size of the
  14  * bitmasks used on that platform, i.e. 32 or 64.  Setting this smaller
  15  * saves quite a bit of memory.
  16  */
  17 #ifdef CONFIG_SMP
  18 #define NR_CPUS         CONFIG_NR_CPUS
  19 #else
  20 #define NR_CPUS         1
  21 #endif
  22
  23 #define MIN_THREADS_LEFT_FOR_ROOT 4
  24
  25 /*
  26  * This controls the default maximum pid allocated to a process
  27  */
  28 #define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
  29
  30 /*
  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.]
  33  */
  34 #define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
  35         (sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
  36
  37 #endif