Thread Stack

檢查系統上每個 thread stack 可以拿到多少 RAM:

# Linux
$ ulimit -s
8192    # 8192 KB = 8 MB

$ ulimit -a
Maximum size of core files created                           (kB, -c) 0
Maximum size of a process’s data segment                     (kB, -d) unlimited
Maximum size of files created by the shell                   (kB, -f) unlimited
Maximum size that may be locked into memory                  (kB, -l) 1024
Maximum resident set size                                    (kB, -m) unlimited
Maximum number of open file descriptors                          (-n) 1024
Maximum stack size                                           (kB, -s) 8192
Maximum amount of cpu time in seconds                   (seconds, -t) unlimited
Maximum number of processes available to a single user           (-u) 23231
Maximum amount of virtual memory available to the shell      (kB, -v) unlimited

# FreeBSD
$ ulimit -s

$ ulimit -a
cpu time               (seconds, -t)  5400
file size           (512-blocks, -f)  unlimited
data seg size           (kbytes, -d)  25600
stack size              (kbytes, -s)  40960
core file size      (512-blocks, -c)  unlimited
max memory size         (kbytes, -m)  65536
locked memory           (kbytes, -l)  40960
max user processes              (-u)  256
open files                      (-n)  100
virtual mem size        (kbytes, -v)  unlimited
swap limit              (kbytes, -w)  unlimited
sbsize                   (bytes, -b)  unlimited
pseudo-terminals                (-p)  unlimited

# Windows 上預設 thread stack limit 是 1 MB

設定檔: /etc/security/limits.conf


* soft stack 2048
* hard stack 2048

man pthread_create

On **Linux/x86-32**, the default stack size for a new thread is **2 megabytes**.
Under the NPTL threading implementation,
if the **RLIMIT_STACK** soft resource limit at the time the program started has any value other than "unlimited",
then it determines the default stack size of new threads.
Using **pthread_attr_setstacksize**(3),
the stack size attribute can be explicitly set in the attr argument used to create a thread,
in order to obtain a stack size other than the default.
  • pthread_attr_setstacksize