Commit 6ef228fc authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Kevin Wolf
Browse files

stream: move rate limiting to a separate header file 



Make the code reusable.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 188a7bbf

block/stream.c

+2 −29
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 


#include "trace.h"

#include "block_int.h"

#include "qemu/ratelimit.h"



enum {

    /*
@@ -25,34 +26,6 @@ enum { 


#define SLICE_TIME 100000000ULL /* ns */



typedef struct {

    int64_t next_slice_time;

    uint64_t slice_quota;

    uint64_t dispatched;

} RateLimit;



static int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)

{

    int64_t now = qemu_get_clock_ns(rt_clock);



    if (limit->next_slice_time < now) {

        limit->next_slice_time = now + SLICE_TIME;

        limit->dispatched = 0;

    }

    if (limit->dispatched == 0 || limit->dispatched + n <= limit->slice_quota) {

        limit->dispatched += n;

        return 0;

    } else {

        limit->dispatched = n;

        return limit->next_slice_time - now;

    }

}



static void ratelimit_set_speed(RateLimit *limit, uint64_t speed)

{

    limit->slice_quota = speed / (1000000000ULL / SLICE_TIME);

}



typedef struct StreamBlockJob {

    BlockJob common;

    RateLimit limit;
@@ -198,7 +171,7 @@ static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp) 
        error_set(errp, QERR_INVALID_PARAMETER, "speed");

        return;

    }

    ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE);

    ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);

}



static BlockJobType stream_job_type = {

include/qemu/ratelimit.h

0 → 100644
+48 −0
Original line number Diff line number Diff line 
/*

 * Ratelimiting calculations

 *

 * Copyright IBM, Corp. 2011

 *

 * Authors:

 *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>

 *

 * This work is licensed under the terms of the GNU LGPL, version 2 or later.

 * See the COPYING.LIB file in the top-level directory.

 *

 */



#ifndef QEMU_RATELIMIT_H

#define QEMU_RATELIMIT_H 1



typedef struct {

    int64_t next_slice_time;

    uint64_t slice_quota;

    uint64_t slice_ns;

    uint64_t dispatched;

} RateLimit;



static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)

{

    int64_t now = qemu_get_clock_ns(rt_clock);



    if (limit->next_slice_time < now) {

        limit->next_slice_time = now + limit->slice_ns;

        limit->dispatched = 0;

    }

    if (limit->dispatched == 0 || limit->dispatched + n <= limit->slice_quota) {

        limit->dispatched += n;

        return 0;

    } else {

        limit->dispatched = n;

        return limit->next_slice_time - now;

    }

}



static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed,

                                       uint64_t slice_ns)

{

    limit->slice_ns = slice_ns;

    limit->slice_quota = ((double)speed * 1000000000ULL) / slice_ns;

}



#endif