xref: /titanic_41/usr/src/cmd/fs.d/nfs/lib/thrpool.c (revision 9b214d32697277d03ed2e5d98c4a7bfef16dcf4d)
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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <thread.h>
27 #include <stdlib.h>
28 #include <errno.h>
29 #include <strings.h>
30 #include <tiuser.h>
31 #include <syslog.h>
32 #include <zone.h>
33 #include <sys/priocntl.h>
34 #include <sys/fxpriocntl.h>
35 #include <nfs/nfs.h>
36 #include <nfs/nfssys.h>
37 #include "thrpool.h"
38 
39 extern	int	_nfssys(int, void *);
40 
41 /*
42  * Thread to call into the kernel and do work on behalf of NFS.
43  */
44 static void *
45 svcstart(void *arg)
46 {
47 	int id = (int)arg;
48 
49 	/*
50 	 * Create a kernel worker thread to service
51 	 * new incoming requests on a pool.
52 	 */
53 	_nfssys(SVCPOOL_RUN, &id);
54 
55 	/*
56 	 * Returned from the kernel, this thread's work is done,
57 	 * and it should exit. For new incoming requests,
58 	 * svcblock() will spawn another worker thread by
59 	 * calling svcstart() again.
60 	 */
61 	thr_exit(NULL);
62 	return (NULL);
63 }
64 
65 static void *
66 svc_rdma_creator(void *arg)
67 {
68 	struct rdma_svc_args *rsap = (struct rdma_svc_args *)arg;
69 
70 	if (_nfssys(RDMA_SVC_INIT, rsap) < 0) {
71 		if (errno != ENODEV) {
72 			(void) syslog(LOG_INFO, "RDMA transport startup "
73 			    "failed with %m");
74 		}
75 	}
76 	free(rsap);
77 	thr_exit(NULL);
78 	return (NULL);
79 }
80 
81 /*
82  * User-space "creator" thread. This thread blocks in the kernel
83  * until new worker threads need to be created for the service
84  * pool. On return to userspace, if there is no error, create a
85  * new thread for the service pool.
86  */
87 static void *
88 svcblock(void *arg)
89 {
90 	int id = (int)arg;
91 
92 	/* CONSTCOND */
93 	while (1) {
94 		thread_t tid;
95 
96 		/*
97 		 * Call into the kernel, and hang out there
98 		 * until a thread needs to be created.
99 		 */
100 		if (_nfssys(SVCPOOL_WAIT, &id) < 0) {
101 			if (errno == ECANCELED || errno == EINTR ||
102 			    errno == EBUSY)
103 				/*
104 				 * If we get back ECANCELED or EINTR,
105 				 * the service pool is exiting, and we
106 				 * may as well clean up this thread. If
107 				 * EBUSY is returned, there's already a
108 				 * thread looping on this pool, so we
109 				 * should give up.
110 				 */
111 				break;
112 			else
113 				continue;
114 		}
115 
116 		/*
117 		 * User portion of the thread does no real work since
118 		 * the svcpool threads actually spend their entire
119 		 * lives in the kernel. So, user portion of the thread
120 		 * should have the smallest stack possible.
121 		 */
122 		(void) thr_create(NULL, THR_MIN_STACK, svcstart, (void *)id,
123 		    THR_BOUND | THR_DETACHED, &tid);
124 	}
125 
126 	thr_exit(NULL);
127 	return (NULL);
128 }
129 
130 void
131 svcsetprio(void)
132 {
133 	pcinfo_t pcinfo;
134 	pri_t maxupri;
135 
136 	/*
137 	 * By default, all threads should be part of the FX scheduler
138 	 * class. As nfsd/lockd server threads used to be part of the
139 	 * kernel, they're used to being scheduled in the SYS class.
140 	 * Userland threads shouldn't be in SYS, but they can be given a
141 	 * higher priority by default. This change still renders nfsd/lockd
142 	 * managable by an admin by utilizing commands to change scheduling
143 	 * manually, or by using resource management tools such as pools
144 	 * to associate them with a different scheduling class and segregate
145 	 * the workload.
146 	 *
147 	 * We set the threads' priority to the upper bound for priorities
148 	 * in FX. This should be 60, but since the desired action is to
149 	 * make nfsd/lockd more important than TS threads, we bow to the
150 	 * system's knowledge rather than setting it manually. Furthermore,
151 	 * since the SYS class doesn't timeslice, use an "infinite" quantum.
152 	 * If anything fails, just log the failure and let the daemon
153 	 * default to TS.
154 	 *
155 	 * The change of scheduling class is expected to fail in a non-global
156 	 * zone, so we avoid worrying the zone administrator unnecessarily.
157 	 */
158 	(void) strcpy(pcinfo.pc_clname, "FX");
159 	if (priocntl(0, 0, PC_GETCID, (caddr_t)&pcinfo) != -1) {
160 		maxupri = ((fxinfo_t *)pcinfo.pc_clinfo)->fx_maxupri;
161 		if (priocntl(P_LWPID, P_MYID, PC_SETXPARMS, "FX",
162 		    FX_KY_UPRILIM, maxupri, FX_KY_UPRI, maxupri,
163 		    FX_KY_TQNSECS, FX_TQINF, NULL) != 0 &&
164 		    getzoneid() == GLOBAL_ZONEID)
165 			(void) syslog(LOG_ERR, "Unable to use FX scheduler: "
166 			    "%m. Using system default scheduler.");
167 	} else
168 		(void) syslog(LOG_ERR, "Unable to determine parameters "
169 		    "for FX scheduler. Using system default scheduler.");
170 }
171 
172 int
173 svcrdma(int id, int versmin, int versmax, int delegation)
174 {
175 	thread_t tid;
176 	struct rdma_svc_args *rsa;
177 
178 	rsa = (struct rdma_svc_args *)malloc(sizeof (struct rdma_svc_args));
179 	rsa->poolid = (uint32_t)id;
180 	rsa->netid = NULL;
181 	rsa->nfs_versmin = versmin;
182 	rsa->nfs_versmax = versmax;
183 	rsa->delegation = delegation;
184 
185 	/*
186 	 * Create a thread to handle RDMA start and stop.
187 	 */
188 	if (thr_create(NULL, THR_MIN_STACK * 2, svc_rdma_creator, (void *)rsa,
189 	    THR_BOUND | THR_DETACHED, &tid))
190 		return (1);
191 
192 	return (0);
193 }
194 
195 int
196 svcwait(int id)
197 {
198 	thread_t tid;
199 
200 	/*
201 	 * Create a bound thread to wait for kernel LWPs that
202 	 * need to be created. This thread also has little need
203 	 * of stackspace, so should be created with that in mind.
204 	 */
205 	if (thr_create(NULL, THR_MIN_STACK * 2, svcblock, (void *)id,
206 	    THR_BOUND | THR_DETACHED, &tid))
207 		return (1);
208 
209 	return (0);
210 }
211