xref: /illumos-gate/usr/src/uts/common/sys/taskq_impl.h (revision fb3b6bbf2c922827ddf076fbf2172d96c58a71de)
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 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 /*
26  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
27  * Copyright (c) 2017 by Delphix. All rights reserved.
28  */
29 
30 #ifndef	_SYS_TASKQ_IMPL_H
31 #define	_SYS_TASKQ_IMPL_H
32 
33 #include <sys/taskq.h>
34 #include <sys/inttypes.h>
35 #include <sys/vmem.h>
36 #include <sys/list.h>
37 #include <sys/kstat.h>
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 typedef struct taskq_bucket taskq_bucket_t;
44 
45 typedef struct taskq_ent {
46 	struct taskq_ent	*tqent_next;
47 	struct taskq_ent	*tqent_prev;
48 	task_func_t		*tqent_func;
49 	void			*tqent_arg;
50 	union {
51 		taskq_bucket_t	*tqent_bucket;
52 		uintptr_t	tqent_flags;
53 	}			tqent_un;
54 	kthread_t		*tqent_thread;
55 	kcondvar_t		tqent_cv;
56 } taskq_ent_t;
57 
58 #define	TQENT_FLAG_PREALLOC	0x1
59 
60 /*
61  * Taskq Statistics fields are not protected by any locks.
62  */
63 typedef struct tqstat {
64 	uint_t		tqs_hits;
65 	uint_t		tqs_misses;
66 	uint_t		tqs_overflow;	/* no threads to allocate   */
67 	uint_t		tqs_tcreates;	/* threads created 	*/
68 	uint_t		tqs_tdeaths;	/* threads died		*/
69 	uint_t		tqs_maxthreads;	/* max # of alive threads */
70 	uint_t		tqs_disptcreates;
71 } tqstat_t;
72 
73 /*
74  * Per-CPU hash bucket manages taskq_bent_t structures using freelist.
75  */
76 struct taskq_bucket {
77 	kmutex_t	tqbucket_lock;
78 	taskq_t		*tqbucket_taskq;	/* Enclosing taskq */
79 	taskq_ent_t	tqbucket_freelist;
80 	uint_t		tqbucket_nalloc;	/* # of allocated entries */
81 	uint_t		tqbucket_nfree;		/* # of free entries */
82 	kcondvar_t	tqbucket_cv;
83 	ushort_t	tqbucket_flags;
84 	hrtime_t	tqbucket_totaltime;
85 	tqstat_t	tqbucket_stat;
86 };
87 
88 /*
89  * Bucket flags.
90  */
91 #define	TQBUCKET_CLOSE		0x01
92 #define	TQBUCKET_SUSPEND	0x02
93 
94 #define	TASKQ_INTERFACE_FLAGS	0x0000ffff	/* defined in <sys/taskq.h> */
95 
96 /*
97  * taskq implementation flags: bit range 16-31
98  */
99 #define	TASKQ_CHANGING		0x00010000	/* nthreads != target */
100 #define	TASKQ_SUSPENDED		0x00020000	/* taskq is suspended */
101 #define	TASKQ_NOINSTANCE	0x00040000	/* no instance number */
102 #define	TASKQ_THREAD_CREATED	0x00080000	/* a thread has been created */
103 #define	TASKQ_DUTY_CYCLE	0x00100000	/* using the SDC class */
104 
105 struct taskq {
106 	char		tq_name[TASKQ_NAMELEN + 1];
107 	kmutex_t	tq_lock;
108 	krwlock_t	tq_threadlock;
109 	kcondvar_t	tq_dispatch_cv;
110 	kcondvar_t	tq_wait_cv;
111 	kcondvar_t	tq_exit_cv;
112 	pri_t		tq_pri;		/* Scheduling priority */
113 	uint_t		tq_flags;
114 	int		tq_active;
115 	int		tq_nthreads;
116 	int		tq_nthreads_target;
117 	int		tq_nthreads_max;
118 	int		tq_threads_ncpus_pct;
119 	int		tq_nalloc;
120 	int		tq_minalloc;
121 	int		tq_maxalloc;
122 	kcondvar_t	tq_maxalloc_cv;
123 	int		tq_maxalloc_wait;
124 	taskq_ent_t	*tq_freelist;
125 	taskq_ent_t	tq_task;
126 	int		tq_maxsize;
127 	taskq_bucket_t	*tq_buckets;	/* Per-cpu array of buckets */
128 	int		tq_instance;
129 	uint_t		tq_nbuckets;	/* # of buckets	(2^n)	    */
130 	union {
131 		kthread_t *_tq_thread;
132 		kthread_t **_tq_threadlist;
133 	}		tq_thr;
134 
135 	list_node_t	tq_cpupct_link;	/* linkage for taskq_cpupct_list */
136 	struct proc	*tq_proc;	/* process for taskq threads */
137 	int		tq_cpupart;	/* cpupart id bound to */
138 	uint_t		tq_DC;		/* duty cycle for SDC */
139 
140 	/*
141 	 * Statistics.
142 	 */
143 	kstat_t		*tq_kstat;	/* Exported statistics */
144 	hrtime_t	tq_totaltime;	/* Time spent processing tasks */
145 	uint64_t	tq_nomem;	/* # of times there was no memory */
146 	uint64_t	tq_tasks;	/* Total # of tasks posted */
147 	uint64_t	tq_executed;	/* Total # of tasks executed */
148 	int		tq_maxtasks;	/* Max number of tasks in the queue */
149 	int		tq_tcreates;
150 	int		tq_tdeaths;
151 };
152 
153 /* Special form of taskq dispatch that uses preallocated entries. */
154 void taskq_dispatch_ent(taskq_t *, task_func_t, void *, uint_t, taskq_ent_t *);
155 
156 
157 #define	tq_thread tq_thr._tq_thread
158 #define	tq_threadlist tq_thr._tq_threadlist
159 
160 /* The MAX guarantees we have at least one thread */
161 #define	TASKQ_THREADS_PCT(ncpus, pct)	MAX(((ncpus) * (pct)) / 100, 1)
162 
163 #ifdef	__cplusplus
164 }
165 #endif
166 
167 #endif	/* _SYS_TASKQ_IMPL_H */
168