Current File : //usr/share/systemtap/examples/process/rlimit_nofile.stp
############################################################
# rlimit_nofile.stp
# Author: Robin Hack <rhack@redhat.com>
# This script watches processes being scheduled and which
# try to allocate a file descriptor without luck.
############################################################
global failed_calls
probe kernel.trace("sched_wakeup")
{
pid = task_pid($p);
name = task_execname($p);
open_ds = task_open_file_handles($p);
max_ds = task_rlimit_nofile($p);
if (failed_calls[name, pid] == "EMFILE") {
printf ("%s %s(%d) open: %d - max: %d Hit: %s\n",
ctime(gettimeofday_s()), name, pid, open_ds, max_ds,
failed_calls[name, pid]);
}
}
probe kernel.trace("sched_process_exit")
{
pid = task_pid($p);
name = task_execname($p);
delete failed_calls[name, pid];
}
# This is exactly point where all the fun happens
# This function returns only EMFILE errno.
probe kernel.function("__alloc_fd@fs/file.c").return !,
kernel.function("alloc_fd").return
{
if (errno_str($return) == "EMFILE")
{
failed_calls[execname(), pid()] = errno_str($return);
}
}
Mini Shell