Hi! On 22:47 Sun 10 Feb , Peter Teoh wrote:
On Sun, Feb 10, 2013 at 8:29 PM, <michi1@michaelblizek.twilightparadox.com>wrote:
Hi!
On 13:10 Sat 09 Feb , horseriver wrote:
hi:)
In one process ,what is the max number of opening file descriptor ?
Type "ulimit -a" in your shell. On my system (debian) the default is 1024.
Hi Michael, nice to see u again.
BTW, many of the parameters as reported by ulimit, also has to be taken with some doubts:
ulimit -a core file size (blocks, -c) unlimited data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 47543 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 47543 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited
the above is for Ubuntu 12.04 with 32-bit kernel (3.2.0) but of course we know that max file size has a limit - depending on whether it is ext2 or ext3 or ext4. cannot remember the exact nos, but general conceptual level, there is a limit.
Well, ulimit is not really there to tell you what the system can handle. It only tries to limit the ressources which can be used for stability/security reasons. Also, even if ulimit would want to tell you what the system can handle, the interface is obviously not suited to export the file system limits when you have more than one file system mounted. File system limits: http://en.wikipedia.org/wiki/Ext3 http://en.wikipedia.org/wiki/Ext4
even for "CPU time"...it is limited by the underlying bit length of representation for time. as usual...i don't know the details :-(, just concept. sorry :-(.
ulimit -t 1 dd if=/dev/zero of=/dev/null It seems cpu limit means that the process will be killed if it exceeds it. -Michi -- programing a layer 3+4 network protocol for mesh networks see http://michaelblizek.twilightparadox.com