On 03/30/2013 06:36 AM, Duke Nguyen wrote:
On 3/30/13 5:22 PM, Duke Nguyen wrote:
On 3/30/13 3:13 PM, Patrick Bégou wrote:
I do not know about your code but:
1) did you check stack limitations ? Typically intel fortran codes
needs large amount of stack when the problem size increase.
Check ulimit -a
First time I heard of stack limitations. Anyway, ulimit -a gives
$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 127368
max locked memory (kbytes, -l) unlimited
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) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 1024
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
So stack size is 10MB??? Does this one create problem? How do I
change this?
I did $ ulimit -s unlimited to have stack size to be unlimited, and
the job ran fine!!! So it looks like stack limit is the problem.
Questions are:
* how do I set this automatically (and permanently)?
* should I set all other ulimits to be unlimited?
In our environment, the only solution we found is to have mpirun run a
script on each node which sets ulimit (as well as environment variables
which are more convenient to set there than in the mpirun), before
starting the executable. We had expert recommendations against this but
no other working solution. It seems unlikely that you would want to
remove any limits which work at default.
Stack size unlimited in reality is not unlimited; it may be limited by a
system limit or implementation. As we run up to 120 threads per rank
and many applications have threadprivate data regions, ability to run
without considering stack limit is the exception rather than the rule.
--
Tim Prince
