xref: /netbsd-src/external/cddl/osnet/dev/dtrace/dtrace_vtime.c (revision ba2539a9805a0544ff82c0003cc02fe1eee5603d)
1 /*	$NetBSD: dtrace_vtime.c,v 1.3 2018/05/28 21:05:03 chs Exp $	*/
2 
3 /*
4  * CDDL HEADER START
5  *
6  * The contents of this file are subject to the terms of the
7  * Common Development and Distribution License (the "License").
8  * You may not use this file except in compliance with the License.
9  *
10  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
11  * or http://www.opensolaris.org/os/licensing.
12  * See the License for the specific language governing permissions
13  * and limitations under the License.
14  *
15  * When distributing Covered Code, include this CDDL HEADER in each
16  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
17  * If applicable, add the following below this CDDL HEADER, with the
18  * fields enclosed by brackets "[]" replaced with your own identifying
19  * information: Portions Copyright [yyyy] [name of copyright owner]
20  *
21  * CDDL HEADER END
22  *
23  * $FreeBSD: head/sys/cddl/dev/dtrace/dtrace_vtime.c 179237 2008-05-23 05:59:42Z jb $
24  */
25 
26 /*
27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 void
dtrace_vtime_enable(void)32 dtrace_vtime_enable(void)
33 {
34 	dtrace_vtime_state_t state, nstate = 0;
35 
36 	do {
37 		state = dtrace_vtime_active;
38 
39 		switch (state) {
40 		case DTRACE_VTIME_INACTIVE:
41 			nstate = DTRACE_VTIME_ACTIVE;
42 			break;
43 
44 		case DTRACE_VTIME_INACTIVE_TNF:
45 			nstate = DTRACE_VTIME_ACTIVE_TNF;
46 			break;
47 
48 		case DTRACE_VTIME_ACTIVE:
49 		case DTRACE_VTIME_ACTIVE_TNF:
50 			panic("DTrace virtual time already enabled");
51 			/*NOTREACHED*/
52 		}
53 
54 	} while	(dtrace_cas32((uint32_t *)&dtrace_vtime_active,
55 	    state, nstate) != state);
56 }
57 
58 void
dtrace_vtime_disable(void)59 dtrace_vtime_disable(void)
60 {
61 	dtrace_vtime_state_t state, nstate = 0;
62 
63 	do {
64 		state = dtrace_vtime_active;
65 
66 		switch (state) {
67 		case DTRACE_VTIME_ACTIVE:
68 			nstate = DTRACE_VTIME_INACTIVE;
69 			break;
70 
71 		case DTRACE_VTIME_ACTIVE_TNF:
72 			nstate = DTRACE_VTIME_INACTIVE_TNF;
73 			break;
74 
75 		case DTRACE_VTIME_INACTIVE:
76 		case DTRACE_VTIME_INACTIVE_TNF:
77 			panic("DTrace virtual time already disabled");
78 			/*NOTREACHED*/
79 		}
80 
81 	} while	(dtrace_cas32((uint32_t *)&dtrace_vtime_active,
82 	    state, nstate) != state);
83 }
84 
85 void
dtrace_vtime_switch(kthread_t * next)86 dtrace_vtime_switch(kthread_t *next)
87 {
88 	dtrace_icookie_t cookie;
89 	hrtime_t ts;
90 
91 	cookie = dtrace_interrupt_disable();
92 	ts = dtrace_gethrtime();
93 
94 	if (curthread->t_dtrace_start != 0) {
95 		curthread->t_dtrace_vtime += ts - curthread->t_dtrace_start;
96 		curthread->t_dtrace_start = 0;
97 	}
98 
99 	if (next != NULL)
100 		next->t_dtrace_start = ts;
101 
102 	dtrace_interrupt_enable(cookie);
103 }
104