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 22:01:07 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