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qemu/include/block/throttle-groups.h

92 lines
3.3 KiB
C

/*
* QEMU block throttling group infrastructure
*
* Copyright (C) Nodalink, EURL. 2014
* Copyright (C) Igalia, S.L. 2015
*
* Authors:
* Benoît Canet <benoit.canet@nodalink.com>
* Alberto Garcia <berto@igalia.com>
*
* This program 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 2 or
* (at your option) version 3 of the License.
*
* This program 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 THROTTLE_GROUPS_H
#define THROTTLE_GROUPS_H
#include "qemu/coroutine.h"
#include "qemu/throttle.h"
#include "qom/object.h"
/* The ThrottleGroupMember structure indicates membership in a ThrottleGroup
* and holds related data.
*/
typedef struct ThrottleGroupMember {
AioContext *aio_context;
/* throttled_reqs_lock protects the CoQueues for throttled requests. */
CoMutex throttled_reqs_lock;
CoQueue throttled_reqs[THROTTLE_MAX];
/* Nonzero if the I/O limits are currently being ignored; generally
* it is zero. Accessed with atomic operations.
*/
unsigned int io_limits_disabled;
/* Number of pending throttle_group_restart_queue_entry() coroutines.
* Accessed with atomic operations.
*/
unsigned int restart_pending;
/* The following fields are protected by the ThrottleGroup lock.
* See the ThrottleGroup documentation for details.
* throttle_state tells us if I/O limits are configured. */
ThrottleState *throttle_state;
ThrottleTimers throttle_timers;
unsigned pending_reqs[THROTTLE_MAX];
QLIST_ENTRY(ThrottleGroupMember) round_robin;
} ThrottleGroupMember;
#define TYPE_THROTTLE_GROUP "throttle-group"
OBJECT_DECLARE_SIMPLE_TYPE(ThrottleGroup, THROTTLE_GROUP)
const char *throttle_group_get_name(ThrottleGroupMember *tgm);
ThrottleState *throttle_group_incref(const char *name);
void throttle_group_unref(ThrottleState *ts);
void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg);
void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg);
void throttle_group_register_tgm(ThrottleGroupMember *tgm,
const char *groupname,
AioContext *ctx);
void throttle_group_unregister_tgm(ThrottleGroupMember *tgm);
void throttle_group_restart_tgm(ThrottleGroupMember *tgm);
void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
int64_t bytes,
ThrottleDirection direction);
void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
AioContext *new_context);
void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);
/*
* throttle_group_exists() must be called under the global
* mutex.
*/
bool throttle_group_exists(const char *name);
#endif