xref: /illumos-gate/usr/src/uts/common/disp/sysclass.c (revision 08855964b9970604433f7b19dcd71cf5af5e5f14)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/sysmacros.h>
33 #include <sys/signal.h>
34 #include <sys/pcb.h>
35 #include <sys/user.h>
36 #include <sys/systm.h>
37 #include <sys/sysinfo.h>
38 #include <sys/var.h>
39 #include <sys/errno.h>
40 #include <sys/cmn_err.h>
41 #include <sys/proc.h>
42 #include <sys/debug.h>
43 #include <sys/inline.h>
44 #include <sys/disp.h>
45 #include <sys/class.h>
46 #include <sys/kmem.h>
47 #include <sys/cpuvar.h>
48 #include <sys/priocntl.h>
49 
50 /*
51  * Class specific code for the sys class. There are no
52  * class specific data structures associated with
53  * the sys class and the scheduling policy is trivially
54  * simple. There is no time slicing.
55  */
56 
57 pri_t		sys_init(id_t, int, classfuncs_t **);
58 static int	sys_getclpri(pcpri_t *);
59 static int	sys_fork(kthread_t *, kthread_t *, void *);
60 static int	sys_enterclass(kthread_t *, id_t, void *, cred_t *, void *);
61 static int	sys_canexit(kthread_t *, cred_t *);
62 static int	sys_nosys();
63 static int	sys_donice(kthread_t *, cred_t *, int, int *);
64 static int	sys_doprio(kthread_t *, cred_t *, int, int *);
65 static void	sys_forkret(kthread_t *, kthread_t *);
66 static void	sys_nullsys();
67 static pri_t	sys_swappri(kthread_t *, int);
68 static pri_t	sys_globpri(kthread_t *);
69 static int	sys_alloc(void **, int);
70 
71 struct classfuncs sys_classfuncs = {
72 	/* messages to class manager */
73 	{
74 		sys_nosys,	/* admin */
75 		sys_nosys,	/* getclinfo */
76 		sys_nosys,	/* parmsin */
77 		sys_nosys,	/* parmsout */
78 		sys_nosys,	/* vaparmsin */
79 		sys_nosys,	/* vaparmsout */
80 		sys_getclpri,	/* getclpri */
81 		sys_alloc,
82 		sys_nullsys,	/* free */
83 	},
84 	/* operations on threads */
85 	{
86 		sys_enterclass,	/* enterclass */
87 		sys_nullsys,	/* exitclass */
88 		sys_canexit,
89 		sys_fork,
90 		sys_forkret,	/* forkret */
91 		sys_nullsys,	/* parmsget */
92 		sys_nosys,	/* parmsset */
93 		sys_nullsys,	/* stop */
94 		sys_nullsys,	/* exit */
95 		sys_nullsys,	/* active */
96 		sys_nullsys,	/* inactive */
97 		sys_swappri,	/* swapin */
98 		sys_swappri,	/* swapout */
99 		sys_nullsys,	/* trapret */
100 		setfrontdq,	/* preempt */
101 		setbackdq,	/* setrun */
102 		sys_nullsys,	/* sleep */
103 		sys_nullsys,	/* tick */
104 		setbackdq,	/* wakeup */
105 		sys_donice,
106 		sys_globpri,	/* globpri */
107 		sys_nullsys,	/* set_process_group */
108 		sys_nullsys,	/* yield */
109 		sys_doprio,
110 	}
111 
112 };
113 
114 
115 /* ARGSUSED */
116 pri_t
117 sys_init(cid, clparmsz, clfuncspp)
118 	id_t		cid;
119 	int		clparmsz;
120 	classfuncs_t	**clfuncspp;
121 {
122 	*clfuncspp = &sys_classfuncs;
123 	return ((pri_t)v.v_maxsyspri);
124 }
125 
126 /*
127  * Get maximum and minimum priorities enjoyed by sysclass threads
128  */
129 static int
130 sys_getclpri(pcpri_t *pcprip)
131 {
132 	pcprip->pc_clpmax = maxclsyspri;
133 	pcprip->pc_clpmin = minclsyspri;
134 	return (0);
135 }
136 
137 /* ARGSUSED */
138 static int
139 sys_enterclass(t, cid, parmsp, reqpcredp, bufp)
140 	kthread_t	*t;
141 	id_t		cid;
142 	void		*parmsp;
143 	cred_t		*reqpcredp;
144 	void		*bufp;
145 {
146 	return (0);
147 }
148 
149 /* ARGSUSED */
150 static int
151 sys_canexit(kthread_t *t, cred_t *reqpcredp)
152 {
153 	return (0);
154 }
155 
156 /* ARGSUSED */
157 static int
158 sys_fork(t, ct, bufp)
159 	kthread_t *t;
160 	kthread_t *ct;
161 	void	*bufp;
162 {
163 	/*
164 	 * No class specific data structure
165 	 */
166 	return (0);
167 }
168 
169 
170 /* ARGSUSED */
171 static void
172 sys_forkret(t, ct)
173 	kthread_t *t;
174 	kthread_t *ct;
175 {
176 	register proc_t *pp = ttoproc(t);
177 	register proc_t *cp = ttoproc(ct);
178 
179 	ASSERT(t == curthread);
180 	ASSERT(MUTEX_HELD(&pidlock));
181 
182 	/*
183 	 * Grab the child's p_lock before dropping pidlock to ensure
184 	 * the process does not disappear before we set it running.
185 	 */
186 	mutex_enter(&cp->p_lock);
187 	mutex_exit(&pidlock);
188 	continuelwps(cp);
189 	mutex_exit(&cp->p_lock);
190 
191 	mutex_enter(&pp->p_lock);
192 	continuelwps(pp);
193 	mutex_exit(&pp->p_lock);
194 }
195 
196 /* ARGSUSED */
197 static pri_t
198 sys_swappri(t, flags)
199 	kthread_t	*t;
200 	int		flags;
201 {
202 	return (-1);
203 }
204 
205 /* ARGSUSED */
206 static pri_t
207 sys_globpri(kthread_t *t __unused)
208 {
209 	return (-1);
210 }
211 
212 static int
213 sys_nosys()
214 {
215 	return (ENOSYS);
216 }
217 
218 
219 static void
220 sys_nullsys()
221 {
222 }
223 
224 /* ARGSUSED */
225 static int
226 sys_donice(kthread_t *t, cred_t *cr, int incr, int *retvalp)
227 {
228 	return (EINVAL);
229 }
230 
231 /* ARGSUSED */
232 static int
233 sys_doprio(kthread_t *t, cred_t *cr, int incr, int *retvalp)
234 {
235 	return (EINVAL);
236 }
237 
238 /* ARGSUSED */
239 static int
240 sys_alloc(void **p, int flag)
241 {
242 	*p = NULL;
243 	return (0);
244 }
245