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      1 #!/usr/sbin/dtrace -qs
      2 /*
      3  * shortlived.d - determine time spent by short lived processes.
      4  *                Written in DTrace (Solaris 10 3/05).
      5  *
      6  * $Id: shortlived.d,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $
      7  *
      8  * USAGE:    shortlived.d	# wait, then hit Ctrl-C
      9  *
     10  * Applications that run many short lived processes can cause load
     11  * on the system that is difficult to identify - the processes
     12  * aren't sampled in time by programs such as prstat. This program
     13  * illustrates how much time was spent processing those extra
     14  * processes, and a table of process name by total times for each.
     15  *
     16  * SEE ALSO: execsnoop
     17  *
     18  * Notes:
     19  * - The measurements are minimum values, not all of the overheads
     20  *   caused by process generation and destruction are measured (DTrace
     21  *   can do so, but the script would become seriously complex).
     22  * - The summary values are accurate, the by program and by PPID values
     23  *   are usually slightly smaller due to rounding errors.
     24  *
     25  * COPYRIGHT: Copyright (c) 2005, 2006 Brendan Gregg.
     26  *
     27  * CDDL HEADER START
     28  *
     29  *  The contents of this file are subject to the terms of the
     30  *  Common Development and Distribution License, Version 1.0 only
     31  *  (the "License").  You may not use this file except in compliance
     32  *  with the License.
     33  *
     34  *  You can obtain a copy of the license at Docs/cddl1.txt
     35  *  or http://www.opensolaris.org/os/licensing.
     36  *  See the License for the specific language governing permissions
     37  *  and limitations under the License.
     38  *
     39  * CDDL HEADER END
     40  *
     41  * 22-Apr-2005  Brendan Gregg   Created this.
     42  * 20-Apr-2006	   "      "	Last update.
     43  */
     44 
     45 /*
     46  * Start
     47  */
     48 dtrace:::BEGIN
     49 {
     50 	/* save start time */
     51 	start = timestamp;
     52 
     53 	/* this is time spent on shortlived processes */
     54 	procs = 0;
     55 
     56 	/* print header */
     57 	printf("Tracing... Hit Ctrl-C to stop.\n");
     58 }
     59 
     60 /*
     61  * Measure parent fork time
     62  */
     63 syscall::*fork*:entry
     64 {
     65 	/* save start of fork */
     66 	self->fork = vtimestamp;
     67 }
     68 syscall::*fork*:return
     69 /arg0 != 0 && self->fork/
     70 {
     71 	/* record elapsed time for the fork syscall */
     72 	this->elapsed = vtimestamp - self->fork;
     73 	procs += this->elapsed;
     74 	self->fork = 0;
     75 }
     76 
     77 /*
     78  * Measure child processes time
     79  */
     80 syscall::*fork*:return
     81 /arg0 == 0/
     82 {
     83 	/* save start of child process */
     84 	self->start = vtimestamp;
     85 
     86 	/* memory cleanup */
     87 	self->fork = 0;
     88 }
     89 proc:::exit
     90 /self->start/
     91 {
     92 	/* record elapsed time for process execution */
     93 	this->elapsed = vtimestamp - self->start;
     94 	procs += this->elapsed;
     95 
     96 	/* sum elapsed by process name and ppid */
     97 	@Times_exec[execname] = sum(this->elapsed/1000000);
     98 	@Times_ppid[ppid] = sum(this->elapsed/1000000);
     99 
    100 	/* memory cleanup */
    101 	self->start = 0;
    102 }
    103 
    104 /*
    105  * Print report
    106  */
    107 dtrace:::END
    108 {
    109 	this->total = timestamp - start;
    110 	printf("short lived processes: %6d.%03d secs\n",
    111 	    procs/1000000000, (procs%1000000000)/1000000);
    112 	printf("total sample duration: %6d.%03d secs\n",
    113 	    this->total/1000000000, (this->total%1000000000)/1000000);
    114 	printf("\nTotal time by process name,\n");
    115 	printa("%18s %@12d ms\n", @Times_exec);
    116 	printf("\nTotal time by PPID,\n");
    117 	printa("%18d %@12d ms\n", @Times_ppid);
    118 }
    119