1 /* 2 * QEMU block throttling group infrastructure 3 * 4 * Copyright (C) Nodalink, EURL. 2014 5 * Copyright (C) Igalia, S.L. 2015 6 * 7 * Authors: 8 * Benoît Canet <benoit.canet@nodalink.com> 9 * Alberto Garcia <berto@igalia.com> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License as 13 * published by the Free Software Foundation; either version 2 or 14 * (at your option) version 3 of the License. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, see <http://www.gnu.org/licenses/>. 23 */ 24 25 #ifndef THROTTLE_GROUPS_H 26 #define THROTTLE_GROUPS_H 27 28 #include "qemu/throttle.h" 29 #include "block/block_int.h" 30 #include "qom/object.h" 31 32 /* The ThrottleGroupMember structure indicates membership in a ThrottleGroup 33 * and holds related data. 34 */ 35 36 typedef struct ThrottleGroupMember { 37 AioContext *aio_context; 38 /* throttled_reqs_lock protects the CoQueues for throttled requests. */ 39 CoMutex throttled_reqs_lock; 40 CoQueue throttled_reqs[2]; 41 42 /* Nonzero if the I/O limits are currently being ignored; generally 43 * it is zero. Accessed with atomic operations. 44 */ 45 unsigned int io_limits_disabled; 46 47 /* Number of pending throttle_group_restart_queue_entry() coroutines. 48 * Accessed with atomic operations. 49 */ 50 unsigned int restart_pending; 51 52 /* The following fields are protected by the ThrottleGroup lock. 53 * See the ThrottleGroup documentation for details. 54 * throttle_state tells us if I/O limits are configured. */ 55 ThrottleState *throttle_state; 56 ThrottleTimers throttle_timers; 57 unsigned pending_reqs[2]; 58 QLIST_ENTRY(ThrottleGroupMember) round_robin; 59 60 } ThrottleGroupMember; 61 62 #define TYPE_THROTTLE_GROUP "throttle-group" 63 typedef struct ThrottleGroup ThrottleGroup; 64 DECLARE_INSTANCE_CHECKER(ThrottleGroup, THROTTLE_GROUP, 65 TYPE_THROTTLE_GROUP) 66 67 const char *throttle_group_get_name(ThrottleGroupMember *tgm); 68 69 ThrottleState *throttle_group_incref(const char *name); 70 void throttle_group_unref(ThrottleState *ts); 71 72 void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg); 73 void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg); 74 75 void throttle_group_register_tgm(ThrottleGroupMember *tgm, 76 const char *groupname, 77 AioContext *ctx); 78 void throttle_group_unregister_tgm(ThrottleGroupMember *tgm); 79 void throttle_group_restart_tgm(ThrottleGroupMember *tgm); 80 81 void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm, 82 unsigned int bytes, 83 bool is_write); 84 void throttle_group_attach_aio_context(ThrottleGroupMember *tgm, 85 AioContext *new_context); 86 void throttle_group_detach_aio_context(ThrottleGroupMember *tgm); 87 /* 88 * throttle_group_exists() must be called under the global 89 * mutex. 90 */ 91 bool throttle_group_exists(const char *name); 92 93 #endif 94