/usr/share/systemtap/examples/process
Edit: /usr/share/systemtap/examples/process/threadstacks.stp (1789B)
#! /bin/sh
//bin/true && exec stap -g $0 ${1+"$@"}
# Override NPTL's "ulimit -s" based default stacksize for new pthreads.
# Invoke with # stap -g threadstacks.stp -Gsize=NNNN
# ... add "-x PID" or "-c CMD", unless you wish to target the entire system.
# ... due to a possible stap bug, might need to add "-d BINARY" for relevant binaries
#
# NB: 'size' needs to be a sufficiently large multiple of the OS pagesize,
# else pthread_create(3) will fail.
#
# See also http://sourceware.org/ml/libc-alpha/2013-01/msg00572.html
global size = 0;
# Notice we're probing "/lib*/*/libpthread.so.*". On RHEL7 ppc64
# systems, the pthread library that gets used is located in
# /lib64/power8/.
probe process("/lib*/libc.so.*").function("allocate_stack")!,
process("/lib*/libpthread.so.*").function("allocate_stack"),
process("/lib*/*/libpthread.so.*").function("allocate_stack")?
{
old_size = @choose_defined($attr->stacksize,
@choose_defined($__default_stacksize,
$__default_pthread_attr->stacksize))
if ((size != 0) && (old_size != size)) { /* requested but not yet changed */
/* change it and report */
if (@defined($attr->stacksize)) {
$attr->stacksize = size
printf("%s[%d] overwrote __default_stacksize@%p (%d->%d)\n",
execname(), tid(), &$attr->stacksize, old_size, size)
} else {
if (@defined($__default_stacksize)) {
$__default_stacksize = size
printf("%s[%d] overwrote __default_stacksize@%p (%d->%d)\n",
execname(), tid(), &$__default_stacksize, old_size, size)
}
else {
$__default_pthread_attr->stacksize = size
printf("%s[%d] overwrote __default_stacksize@%p (%d->%d)\n",
execname(), tid(), &$__default_pthread_attr->stacksize,
old_size, size)
}
}
}
}