include/sys/taskq.h

   1 /*
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://zfsonlinux.org/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 #ifndef _SPL_TASKQ_H
  26 #define _SPL_TASKQ_H
  27
  28 #include <linux/module.h>
  29 #include <linux/gfp.h>
  30 #include <linux/slab.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/kthread.h>
  33 #include <linux/wait_compat.h>
  34 #include <sys/types.h>
  35 #include <sys/thread.h>
  36 #include <sys/rwlock.h>
  37
  38 #define TASKQ_NAMELEN           31
  39
  40 #define TASKQ_PREPOPULATE       0x00000001
  41 #define TASKQ_CPR_SAFE          0x00000002
  42 #define TASKQ_DYNAMIC           0x00000004
  43 #define TASKQ_THREADS_CPU_PCT   0x00000008
  44 #define TASKQ_DC_BATCH          0x00000010
  45 #define TASKQ_ACTIVE            0x80000000
  46
  47 /*
  48  * Flags for taskq_dispatch. TQ_SLEEP/TQ_NOSLEEP should be same as
  49  * KM_SLEEP/KM_NOSLEEP.  TQ_NOQUEUE/TQ_NOALLOC are set particularly
  50  * large so as not to conflict with already used GFP_* defines.
  51  */
  52 #define TQ_SLEEP                0x00000000
  53 #define TQ_NOSLEEP              0x00000001
  54 #define TQ_PUSHPAGE             0x00000002
  55 #define TQ_NOQUEUE              0x01000000
  56 #define TQ_NOALLOC              0x02000000
  57 #define TQ_NEW                  0x04000000
  58 #define TQ_FRONT                0x08000000
  59
  60 /*
  61  * Reserved taskqid values.
  62  */
  63 #define TASKQID_INVALID         ((taskqid_t)0)
  64 #define TASKQID_INITIAL         ((taskqid_t)1)
  65
  66 /*
  67  * spin_lock(lock) and spin_lock_nested(lock,0) are equivalent,
  68  * so TQ_LOCK_DYNAMIC must not evaluate to 0
  69  */
  70 typedef enum tq_lock_role {
  71         TQ_LOCK_GENERAL =       0,
  72         TQ_LOCK_DYNAMIC =       1,
  73 } tq_lock_role_t;
  74
  75 typedef unsigned long taskqid_t;
  76 typedef void (task_func_t)(void *);
  77
  78 typedef struct taskq {
  79         spinlock_t              tq_lock;        /* protects taskq_t */
  80         char                    *tq_name;       /* taskq name */
  81         int                     tq_instance;    /* instance of tq_name */
  82         struct list_head        tq_thread_list; /* list of all threads */
  83         struct list_head        tq_active_list; /* list of active threads */
  84         int                     tq_nactive;     /* # of active threads */
  85         int                     tq_nthreads;    /* # of existing threads */
  86         int                     tq_nspawn;      /* # of threads being spawned */
  87         int                     tq_maxthreads;  /* # of threads maximum */
  88         int                     tq_pri;         /* priority */
  89         int                     tq_minalloc;    /* min taskq_ent_t pool size */
  90         int                     tq_maxalloc;    /* max taskq_ent_t pool size */
  91         int                     tq_nalloc;      /* cur taskq_ent_t pool size */
  92         uint_t                  tq_flags;       /* flags */
  93         taskqid_t               tq_next_id;     /* next pend/work id */
  94         taskqid_t               tq_lowest_id;   /* lowest pend/work id */
  95         struct list_head        tq_free_list;   /* free taskq_ent_t's */
  96         struct list_head        tq_pend_list;   /* pending taskq_ent_t's */
  97         struct list_head        tq_prio_list;   /* priority pending taskq_ent_t's */
  98         struct list_head        tq_delay_list;  /* delayed taskq_ent_t's */
  99         struct list_head        tq_taskqs;      /* all taskq_t's */
 100         spl_wait_queue_head_t   tq_work_waitq;  /* new work waitq */
 101         spl_wait_queue_head_t   tq_wait_waitq;  /* wait waitq */
 102         tq_lock_role_t          tq_lock_class;  /* class when taking tq_lock */
 103 } taskq_t;
 104
 105 typedef struct taskq_ent {
 106         spinlock_t              tqent_lock;
 107         spl_wait_queue_head_t   tqent_waitq;
 108         struct timer_list       tqent_timer;
 109         struct list_head        tqent_list;
 110         taskqid_t               tqent_id;
 111         task_func_t             *tqent_func;
 112         void                    *tqent_arg;
 113         taskq_t                 *tqent_taskq;
 114         uintptr_t               tqent_flags;
 115         unsigned long           tqent_birth;
 116 } taskq_ent_t;
 117
 118 #define TQENT_FLAG_PREALLOC     0x1
 119 #define TQENT_FLAG_CANCEL       0x2
 120
 121 typedef struct taskq_thread {
 122         struct list_head        tqt_thread_list;
 123         struct list_head        tqt_active_list;
 124         struct task_struct      *tqt_thread;
 125         taskq_t                 *tqt_tq;
 126         taskqid_t               tqt_id;
 127         taskq_ent_t             *tqt_task;
 128         uintptr_t               tqt_flags;
 129 } taskq_thread_t;
 130
 131 /* Global system-wide dynamic task queue available for all consumers */
 132 extern taskq_t *system_taskq;
 133 /* Global dynamic task queue for long delay */
 134 extern taskq_t *system_delay_taskq;
 135
 136 /* List of all taskqs */
 137 extern struct list_head tq_list;
 138 extern struct rw_semaphore tq_list_sem;
 139
 140 extern taskqid_t taskq_dispatch(taskq_t *, task_func_t, void *, uint_t);
 141 extern taskqid_t taskq_dispatch_delay(taskq_t *, task_func_t, void *,
 142     uint_t, clock_t);
 143 extern void taskq_dispatch_ent(taskq_t *, task_func_t, void *, uint_t,
 144     taskq_ent_t *);
 145 extern int taskq_empty_ent(taskq_ent_t *);
 146 extern void taskq_init_ent(taskq_ent_t *);
 147 extern taskq_t *taskq_create(const char *, int, pri_t, int, int, uint_t);
 148 extern void taskq_destroy(taskq_t *);
 149 extern void taskq_wait_id(taskq_t *, taskqid_t);
 150 extern void taskq_wait_outstanding(taskq_t *, taskqid_t);
 151 extern void taskq_wait(taskq_t *);
 152 extern int taskq_cancel_id(taskq_t *, taskqid_t);
 153 extern int taskq_member(taskq_t *, kthread_t *);
 154
 155 #define taskq_create_proc(name, nthreads, pri, min, max, proc, flags) \
 156     taskq_create(name, nthreads, pri, min, max, flags)
 157 #define taskq_create_sysdc(name, nthreads, min, max, proc, dc, flags) \
 158     taskq_create(name, nthreads, maxclsyspri, min, max, flags)
 159
 160 int spl_taskq_init(void);
 161 void spl_taskq_fini(void);
 162
 163 #endif  /* _SPL_TASKQ_H */