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Diffstat (limited to 'qemu/include/qemu/throttle.h')
| -rw-r--r-- | qemu/include/qemu/throttle.h | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/qemu/include/qemu/throttle.h b/qemu/include/qemu/throttle.h deleted file mode 100644 index 910965760..000000000 --- a/qemu/include/qemu/throttle.h +++ /dev/null @@ -1,156 +0,0 @@ -/* - * QEMU throttling infrastructure - * - * Copyright (C) Nodalink, EURL. 2013-2014 - * Copyright (C) Igalia, S.L. 2015-2016 - * - * 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_H -#define THROTTLE_H - -#include "qemu-common.h" -#include "qemu/timer.h" - -#define THROTTLE_VALUE_MAX 1000000000000000LL - -typedef enum { - THROTTLE_BPS_TOTAL, - THROTTLE_BPS_READ, - THROTTLE_BPS_WRITE, - THROTTLE_OPS_TOTAL, - THROTTLE_OPS_READ, - THROTTLE_OPS_WRITE, - BUCKETS_COUNT, -} BucketType; - -/* - * This module implements I/O limits using the leaky bucket - * algorithm. The code is independent of the I/O units, but it is - * currently used for bytes per second and operations per second. - * - * Three parameters can be set by the user: - * - * - avg: the desired I/O limits in units per second. - * - max: the limit during bursts, also in units per second. - * - burst_length: the maximum length of the burst period, in seconds. - * - * Here's how it works: - * - * - The bucket level (number of performed I/O units) is kept in - * bkt.level and leaks at a rate of bkt.avg units per second. - * - * - The size of the bucket is bkt.max * bkt.burst_length. Once the - * bucket is full no more I/O is performed until the bucket leaks - * again. This is what makes the I/O rate bkt.avg. - * - * - The bkt.avg rate does not apply until the bucket is full, - * allowing the user to do bursts until then. The I/O limit during - * bursts is bkt.max. To enforce this limit we keep an additional - * bucket in bkt.burst_length that leaks at a rate of bkt.max units - * per second. - * - * - Because of all of the above, the user can perform I/O at a - * maximum of bkt.max units per second for at most bkt.burst_length - * seconds in a row. After that the bucket will be full and the I/O - * rate will go down to bkt.avg. - * - * - Since the bucket always leaks at a rate of bkt.avg, this also - * determines how much the user needs to wait before being able to - * do bursts again. - */ - -typedef struct LeakyBucket { - double avg; /* average goal in units per second */ - double max; /* leaky bucket max burst in units */ - double level; /* bucket level in units */ - double burst_level; /* bucket level in units (for computing bursts) */ - unsigned burst_length; /* max length of the burst period, in seconds */ -} LeakyBucket; - -/* The following structure is used to configure a ThrottleState - * It contains a bit of state: the bucket field of the LeakyBucket structure. - * However it allows to keep the code clean and the bucket field is reset to - * zero at the right time. - */ -typedef struct ThrottleConfig { - LeakyBucket buckets[BUCKETS_COUNT]; /* leaky buckets */ - uint64_t op_size; /* size of an operation in bytes */ -} ThrottleConfig; - -typedef struct ThrottleState { - ThrottleConfig cfg; /* configuration */ - int64_t previous_leak; /* timestamp of the last leak done */ -} ThrottleState; - -typedef struct ThrottleTimers { - QEMUTimer *timers[2]; /* timers used to do the throttling */ - QEMUClockType clock_type; /* the clock used */ - - /* Callbacks */ - QEMUTimerCB *read_timer_cb; - QEMUTimerCB *write_timer_cb; - void *timer_opaque; -} ThrottleTimers; - -/* operations on single leaky buckets */ -void throttle_leak_bucket(LeakyBucket *bkt, int64_t delta); - -int64_t throttle_compute_wait(LeakyBucket *bkt); - -/* init/destroy cycle */ -void throttle_init(ThrottleState *ts); - -void throttle_timers_init(ThrottleTimers *tt, - AioContext *aio_context, - QEMUClockType clock_type, - QEMUTimerCB *read_timer_cb, - QEMUTimerCB *write_timer_cb, - void *timer_opaque); - -void throttle_timers_destroy(ThrottleTimers *tt); - -void throttle_timers_detach_aio_context(ThrottleTimers *tt); - -void throttle_timers_attach_aio_context(ThrottleTimers *tt, - AioContext *new_context); - -bool throttle_timers_are_initialized(ThrottleTimers *tt); - -/* configuration */ -bool throttle_enabled(ThrottleConfig *cfg); - -bool throttle_is_valid(ThrottleConfig *cfg, Error **errp); - -void throttle_config(ThrottleState *ts, - ThrottleTimers *tt, - ThrottleConfig *cfg); - -void throttle_get_config(ThrottleState *ts, ThrottleConfig *cfg); - -void throttle_config_init(ThrottleConfig *cfg); - -/* usage */ -bool throttle_schedule_timer(ThrottleState *ts, - ThrottleTimers *tt, - bool is_write); - -void throttle_account(ThrottleState *ts, bool is_write, uint64_t size); - -#endif |