The bps_max/iops_max values are meaningless without corresponding bps/iops values. Reported an error if bps_max/iops_max is given without bps/iops. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1438683733-21111-2-git-send-email-stefanha@redhat.com
		
			
				
	
	
		
			133 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * QEMU throttling infrastructure
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 *
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 * Copyright (C) Nodalink, EURL. 2013-2014
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 * Copyright (C) Igalia, S.L. 2015
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 *
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 * Authors:
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 *   Benoît Canet <benoit.canet@nodalink.com>
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 *   Alberto Garcia <berto@igalia.com>
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation; either version 2 or
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 * (at your option) version 3 of the License.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, see <http://www.gnu.org/licenses/>.
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 */
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#ifndef THROTTLE_H
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#define THROTTLE_H
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#include <stdint.h>
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#include "qemu-common.h"
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#include "qemu/timer.h"
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typedef enum {
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    THROTTLE_BPS_TOTAL,
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    THROTTLE_BPS_READ,
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    THROTTLE_BPS_WRITE,
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    THROTTLE_OPS_TOTAL,
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    THROTTLE_OPS_READ,
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    THROTTLE_OPS_WRITE,
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    BUCKETS_COUNT,
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} BucketType;
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/*
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 * The max parameter of the leaky bucket throttling algorithm can be used to
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 * allow the guest to do bursts.
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 * The max value is a pool of I/O that the guest can use without being throttled
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 * at all. Throttling is triggered once this pool is empty.
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 */
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typedef struct LeakyBucket {
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    double  avg;              /* average goal in units per second */
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    double  max;              /* leaky bucket max burst in units */
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    double  level;            /* bucket level in units */
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} LeakyBucket;
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/* The following structure is used to configure a ThrottleState
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 * It contains a bit of state: the bucket field of the LeakyBucket structure.
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 * However it allows to keep the code clean and the bucket field is reset to
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 * zero at the right time.
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 */
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typedef struct ThrottleConfig {
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    LeakyBucket buckets[BUCKETS_COUNT]; /* leaky buckets */
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    uint64_t op_size;         /* size of an operation in bytes */
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} ThrottleConfig;
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typedef struct ThrottleState {
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    ThrottleConfig cfg;       /* configuration */
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    int64_t previous_leak;    /* timestamp of the last leak done */
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} ThrottleState;
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typedef struct ThrottleTimers {
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    QEMUTimer *timers[2];     /* timers used to do the throttling */
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    QEMUClockType clock_type; /* the clock used */
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    /* Callbacks */
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    QEMUTimerCB *read_timer_cb;
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    QEMUTimerCB *write_timer_cb;
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    void *timer_opaque;
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} ThrottleTimers;
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/* operations on single leaky buckets */
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void throttle_leak_bucket(LeakyBucket *bkt, int64_t delta);
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int64_t throttle_compute_wait(LeakyBucket *bkt);
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/* expose timer computation function for unit tests */
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bool throttle_compute_timer(ThrottleState *ts,
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                            bool is_write,
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                            int64_t now,
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                            int64_t *next_timestamp);
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/* init/destroy cycle */
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void throttle_init(ThrottleState *ts);
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void throttle_timers_init(ThrottleTimers *tt,
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                          AioContext *aio_context,
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                          QEMUClockType clock_type,
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                          QEMUTimerCB *read_timer_cb,
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                          QEMUTimerCB *write_timer_cb,
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                          void *timer_opaque);
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void throttle_timers_destroy(ThrottleTimers *tt);
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void throttle_timers_detach_aio_context(ThrottleTimers *tt);
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void throttle_timers_attach_aio_context(ThrottleTimers *tt,
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                                        AioContext *new_context);
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bool throttle_timers_are_initialized(ThrottleTimers *tt);
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/* configuration */
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bool throttle_enabled(ThrottleConfig *cfg);
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bool throttle_conflicting(ThrottleConfig *cfg);
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bool throttle_is_valid(ThrottleConfig *cfg);
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bool throttle_max_is_missing_limit(ThrottleConfig *cfg);
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void throttle_config(ThrottleState *ts,
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                     ThrottleTimers *tt,
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                     ThrottleConfig *cfg);
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void throttle_get_config(ThrottleState *ts, ThrottleConfig *cfg);
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/* usage */
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bool throttle_schedule_timer(ThrottleState *ts,
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                             ThrottleTimers *tt,
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                             bool is_write);
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void throttle_account(ThrottleState *ts, bool is_write, uint64_t size);
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#endif
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