| 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/coroutine.h" |
| 29 | #include "qemu/throttle.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 | /* Protected by ThrottleGroup.lock */ |
| 39 | CoQueue throttled_reqs[THROTTLE_MAX]; |
| 40 | |
| 41 | /* Nonzero if the I/O limits are currently being ignored; generally |
| 42 | * it is zero. Accessed with atomic operations. |
| 43 | */ |
| 44 | unsigned int io_limits_disabled; |
| 45 | |
| 46 | /* Number of pending throttle_group_restart_queue_entry() coroutines. |
| 47 | * Accessed with atomic operations. |
| 48 | */ |
| 49 | unsigned int restart_pending; |
| 50 | |
| 51 | /* The following fields are protected by the ThrottleGroup lock. |
| 52 | * See the ThrottleGroup documentation for details. |
| 53 | * throttle_state tells us if I/O limits are configured. */ |
| 54 | ThrottleState *throttle_state; |
| 55 | ThrottleTimers throttle_timers; |
| 56 | unsigned pending_reqs[THROTTLE_MAX]; |
| 57 | QLIST_ENTRY(ThrottleGroupMember) round_robin; |
| 58 | |
| 59 | } ThrottleGroupMember; |
| 60 | |
| 61 | #define TYPE_THROTTLE_GROUP "throttle-group" |
| 62 | OBJECT_DECLARE_SIMPLE_TYPE(ThrottleGroup, THROTTLE_GROUP) |
| 63 | |
| 64 | const char *throttle_group_get_name(ThrottleGroupMember *tgm); |
| 65 | |
| 66 | ThrottleState *throttle_group_incref(const char *name); |
| 67 | void throttle_group_unref(ThrottleState *ts); |
| 68 | |
| 69 | void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg); |
| 70 | void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg); |
| 71 | |
| 72 | void throttle_group_register_tgm(ThrottleGroupMember *tgm, |
| 73 | const char *groupname, |
| 74 | AioContext *ctx); |
| 75 | void throttle_group_unregister_tgm(ThrottleGroupMember *tgm); |
| 76 | void throttle_group_restart_tgm(ThrottleGroupMember *tgm); |
| 77 | |
| 78 | void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm, |
| 79 | int64_t bytes, |
| 80 | ThrottleDirection direction); |
| 81 | void throttle_group_attach_aio_context(ThrottleGroupMember *tgm, |
| 82 | AioContext *new_context); |
| 83 | void throttle_group_detach_aio_context(ThrottleGroupMember *tgm); |
| 84 | /* |
| 85 | * throttle_group_exists() must be called under the global |
| 86 | * mutex. |
| 87 | */ |
| 88 | bool throttle_group_exists(const char *name); |
| 89 | |
| 90 | #endif |