summaryrefslogtreecommitdiffstats
path: root/xlators/performance/io-threads/src/io-threads.h
blob: c5ca760000a3863844d15b13ebdc437a57634c9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
  Copyright (c) 2006-2009 Z RESEARCH, Inc. <http://www.zresearch.com>
  This file is part of GlusterFS.

  GlusterFS is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published
  by the Free Software Foundation; either version 3 of the License,
  or (at your option) any later version.

  GlusterFS is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see
  <http://www.gnu.org/licenses/>.
*/

#ifndef __IOT_H
#define __IOT_H

#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif


#include "compat-errno.h"
#include "glusterfs.h"
#include "logging.h"
#include "dict.h"
#include "xlator.h"
#include "common-utils.h"
#include "list.h"
#include <stdlib.h>

#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))

struct iot_conf;
struct iot_worker;
struct iot_request;

struct iot_request {
        struct list_head list;        /* Attaches this request to the list of
                                         requests.
                                      */
        call_stub_t *stub;
};

typedef enum {
        IOT_STATE_ACTIVE,
        IOT_STATE_EXIT_REQUEST,
        IOT_STATE_DEAD
}iot_state_t;
#define iot_worker_active(wrk)  ((wrk)->state == IOT_STATE_ACTIVE)

#define MAX_IDLE_SKEW                   1000    /* usecs */
#define skew_usec_idle_time(usec)       ((usec) + (random () % MAX_IDLE_SKEW))
#define IOT_DEFAULT_IDLE                180     /* In secs. */

#define IOT_MIN_THREADS         2
#define IOT_DEFAULT_THREADS     16
#define IOT_MAX_THREADS         64

#define IOT_SCALING_OFF                 _gf_false
#define IOT_SCALING_ON                  _gf_true
#define iot_ordered_scaling_on(conf)    ((conf)->o_scaling == IOT_SCALING_ON)
#define iot_unordered_scaling_on(conf)  ((conf)->u_scaling == IOT_SCALING_ON)

#define IOT_THREAD_STACK_SIZE   ((size_t)(1024*1024))

/* This signifies the max number of outstanding request we're expecting
 * at a point for every worker thread.
 * For an idea of the memory foot-print, consider at most 16 Bytes per
 * iot_request_t on a 64-bit system with another 16 bytes per chunk in the
 * header. For 64 slots in the pool, we'll use up 2 KiB, with 64 threads this
 * goes up to 128 KiB.
 *
 * Note that this size defines the size of the per-worker mem pool. The
 * advantage is that, we're not only reducing the rate of small iot_request_t
 * allocations from the heap but also reducing the contention on the libc heap
 * by having a mem pool, though small, for each worker.
 */
#define IOT_REQUEST_MEMPOOL_SIZE        64

struct iot_worker {
        struct list_head rqlist;      /* List of requests assigned to me. */
        struct iot_conf  *conf;
        int64_t          q,dq;
        pthread_cond_t   dq_cond;
        pthread_mutex_t  qlock;
        int32_t          queue_size;
        pthread_t        thread;
        iot_state_t      state;            /* What state is the thread in. */
        int              thread_idx;       /* Thread's index into the worker
                                              array. Since this will be thread
                                              local data, for ensuring that
                                              number of threads dont fall below
                                              a minimum, we just dont allow
                                              threads with specific indices to
                                              exit. Helps us in eliminating one
                                              place where otherwise a lock
                                              would have been required to update
                                              centralized state inside conf.
                                           */
        struct mem_pool  *req_pool;    /* iot_request_t's come from here. */
};

struct iot_conf {
        int32_t              thread_count;
        struct iot_worker  **workers;

        xlator_t            *this;
        /* Config state for ordered threads. */
        pthread_mutex_t      otlock;       /* Used to sync any state that needs
                                              to be changed by the ordered
                                              threads.
                                           */

        int                  max_o_threads; /* Max. number of ordered threads */
        int                  min_o_threads; /* Min. number of ordered threads.
                                               Ordered thread count never falls
                                               below this threshold.
                                            */

        int                  o_idle_time;   /* in Secs. The idle time after
                                               which an ordered thread exits.
                                            */
        gf_boolean_t         o_scaling;     /* Set to IOT_SCALING_OFF if user
                                               does not want thread scaling on
                                               ordered threads. If scaling is
                                               off, io-threads maintains at
                                               least min_o_threads number of
                                               threads and never lets any thread
                                               exit.
                                            */
        struct iot_worker  **oworkers;      /* Ordered thread pool. */


        /* Config state for unordered threads */
        pthread_mutex_t      utlock;       /* Used for scaling un-ordered
                                              threads. */
        struct iot_worker  **uworkers;     /* Un-ordered thread pool. */
        int                  max_u_threads; /* Number of unordered threads will
                                               not be higher than this. */
        int                  min_u_threads; /* Number of unordered threads
                                               should not fall below this value.
                                            */
        int                  u_idle_time;   /* If an unordered thread does not
                                               get a request for this amount of
                                               secs, it should try to die.
                                            */
        gf_boolean_t         u_scaling;     /* Set to IOT_SCALING_OFF if user
                                               does not want thread scaling on
                                               unordered threads. If scaling is
                                               off, io-threads maintains at
                                               least min_u_threads number of
                                               threads and never lets any thread
                                               exit.
                                            */

        pthread_attr_t       w_attr;        /* Used to reduce the stack size of
                                               the pthread worker down from the
                                               default of 8MiB.
                                            */
};

typedef struct iot_conf iot_conf_t;
typedef struct iot_worker iot_worker_t;
typedef struct iot_request iot_request_t;

#endif /* __IOT_H */