#!/usr/sbin/dtrace -s /* * dnlcsnoop.d - snoop DNLC activity. * Written in DTrace (Solaris 10 3/05). * * The DNLC is the Directory Name Lookup Cache. Filename lookups often * return a hit from here, before needing to traverse the regular file * system cache or go to disk. * * $Id: dnlcsnoop.d,v 1.1.1.1 2015/09/30 22:01:07 christos Exp $ * * USAGE: dnlcsnoop.d # wait several seconds, then hit Ctrl-C * * FIELDS: * PID Process ID * CMD Command name * TIME Elapsed time for lookup, us * HIT DNLC hit Y/N * PATH Path for DNLC lookup * * COPYRIGHT: Copyright (c) 2005, 2006 Brendan Gregg. * * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License, Version 1.0 only * (the "License"). You may not use this file except in compliance * with the License. * * You can obtain a copy of the license at Docs/cddl1.txt * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * CDDL HEADER END * * 27-Mar-2004 Brendan Gregg Created this. * 14-Jun-2005 " " Rewrote this a lot. * 20-Apr-2006 " " Last update. */ #pragma D option quiet /* * Print header */ dtrace:::BEGIN { printf("%6s %-12s %5s %3s %s\n", "PID", "CMD", "TIME", "HIT", "PATH"); } /* * DNLC lookup */ fbt:genunix:dnlc_lookup:entry { /* store path */ self->path = stringof(args[0]->v_path); /* check for trailing "/" */ this->len = strlen(self->path); self->join = *(char *)(args[0]->v_path + this->len - 1) == '/' ? "" : "/"; /* store lookup name */ self->name = stringof(arg1); /* store start time */ self->start = timestamp; } /* * DNLC return */ fbt:genunix:dnlc_lookup:return /self->start/ { /* calculate elapsed time */ this->elapsed = (timestamp - self->start) / 1000; /* print output */ printf("%6d %-12.12s %5d %3s %s%s%s\n", pid, execname, this->elapsed, arg1 == 0 ? "N" : "Y", self->path, self->join, self->name); /* clear variables */ self->path = 0; self->join = 0; self->name = 0; self->start = 0; }