1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma D option quiet 28 29 io:::start 30 { 31 start[args[0]->b_edev, args[0]->b_blkno] = timestamp; 32 } 33 34 io:::done 35 /start[args[0]->b_edev, args[0]->b_blkno]/ 36 { 37 /* 38 * We want to get an idea of our throughput to this device in KB/sec. 39 * What we have, however, is nanoseconds and bytes. That is we want 40 * to calculate: 41 * 42 * bytes / 1024 43 * ------------------------ 44 * nanoseconds / 1000000000 45 * 46 * But we can't calculate this using integer arithmetic without losing 47 * precision (the denomenator, for one, is between 0 and 1 for nearly 48 * all I/Os). So we restate the fraction, and cancel: 49 * 50 * bytes 1000000000 bytes 976562 51 * --------- * ------------- = --------- * ------------- 52 * 1024 nanoseconds 1 nanoseconds 53 * 54 * This is easy to calculate using integer arithmetic; this is what 55 * we do below. 56 */ 57 this->elapsed = timestamp - start[args[0]->b_edev, args[0]->b_blkno]; 58 @[args[1]->dev_statname, args[1]->dev_pathname] = 59 quantize((args[0]->b_bcount * 976562) / this->elapsed); 60 start[args[0]->b_edev, args[0]->b_blkno] = 0; 61 } 62 63 END 64 { 65 printa(" %s (%s)\n%@d\n", @); 66 } 67