page_faults_file.stp

#! /usr/bin/env stap

/*
 * Viacheslav Biriukov 2013
 * 
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Print out pathes to mmap files, that cause major page faults.
 *
 * Useful in cases when you're looking for files for warm up in a memory
 * before start (eg mongodb files, kioto cabinet, homebrew data base).
 * 
 * Using with custom command:
 *
 *    stap ./page_faults_file.stp -c 'firefox'
 *
 * using with running app with PID: 
 * 
 *    stap ./page_faults_file.stp -x 2412
 *
 */

global targetpid

probe begin {
  targetpid = target()
}

probe kernel.function("page_cache_read") {
    if (targetpid == pid()) {
        parent = @cast($file, "file")->f_path->dentry->d_parent;
        fname = __file_filename($file)
        path = reverse_path_walk(parent) ."/".fname
        printf("%s\n", path)
    }
}

probe end {
    delete targetpid
}