[libvirt] [PATCH v1 04/11] bandwidth: Create rate update function

[Laine Stump]

On 11/19/2012 11:51 AM, Michal Privoznik wrote:
> This will be used whenever a NIC with guaranteed throughput is to
> be plugged into a bridge. It will adjust the average throughput of
> non guaranteed NICs (classid 1:2) to meet new requirements.
> ---
>  src/util/virnetdevbandwidth.c |   49 +++++++++++++++++++++++++++++++++++++++++
>  src/util/virnetdevbandwidth.h |    6 +++++
>  2 files changed, 55 insertions(+), 0 deletions(-)
>
> diff --git a/src/util/virnetdevbandwidth.c b/src/util/virnetdevbandwidth.c
> index 9597dcd..3abe7e2 100644
> --- a/src/util/virnetdevbandwidth.c
> +++ b/src/util/virnetdevbandwidth.c
> @@ -463,3 +463,52 @@ cleanup:
>      virCommandFree(cmd);
>      return ret;
>  }
> +
> +/**
> + * virNetDevBandwidthUpdateRate:
> + * @ifname: interface name
> + * @classid: ID of class to update
> + * @new_rate: new rate
> + *
> + * This function updates the 'rate' attribute of HTB class.
> + * It can be used whenever a new interface is plugged to a
> + * bridge to adjust average throughput of non guaranteed
> + * NICs.

So it's changing the "average" for that NIC to something other than what
was configured? Is a record of this kept anywhere? (or maybe it's not
necessary).

> + *
> + * Returns 0 on success, -1 otherwise.
> + */
> +int
> +virNetDevBandwidthUpdateRate(const char *ifname,
> +                             const char *class_id,
> +                             virNetDevBandwidthPtr bandwidth,
> +                             unsigned long long new_rate)
> +{
> +    int ret = -1;
> +    virCommandPtr cmd = NULL;
> +    char *rate = NULL;
> +    char *ceil = NULL;
> +
> +    if (virAsprintf(&rate, "%llukbps", new_rate) < 0 ||
> +        virAsprintf(&ceil, "%llukbps", bandwidth->in->peak ?
> +                    bandwidth->in->peak :
> +                    bandwidth->in->average) < 0) {
> +        virReportOOMError();
> +        goto cleanup;
> +    }
> +
> +    cmd = virCommandNew(TC);
> +    virCommandAddArgList(cmd, "class", "change", "dev", ifname,
> +                         "classid", class_id, "htb", "rate", rate,
> +                         "ceil", ceil, NULL);
> +
> +    if (virCommandRun(cmd, NULL) < 0)
> +        goto cleanup;
> +
> +    ret = 0;
> +
> +cleanup:
> +    virCommandFree(cmd);
> +    VIR_FREE(rate);
> +    VIR_FREE(ceil);
> +    return ret;
> +}
> diff --git a/src/util/virnetdevbandwidth.h b/src/util/virnetdevbandwidth.h
> index 19eb418..a5d595e 100644
> --- a/src/util/virnetdevbandwidth.h
> +++ b/src/util/virnetdevbandwidth.h
> @@ -67,4 +67,10 @@ int virNetDevBandwidthUnplug(const char *brname,
>                               unsigned int id)
>      ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
>  
> +int virNetDevBandwidthUpdateRate(const char *ifname,
> +                                 const char *class_id,
> +                                 virNetDevBandwidthPtr bandwidth,
> +                                 unsigned long long new_rate)
> +    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2)
> +    ATTRIBUTE_RETURN_CHECK;
>  #endif /* __VIR_NETDEV_BANDWIDTH_H__ */

ACK.