Re: [B.A.T.M.A.N.] [RFC 12/23] batman-adv: add base throughput attribute

Antonio Quartulli
2014-02-12T12:20:17Z

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On 12/02/14 09:40, Andrew Lunn wrote:
> On Tue, Feb 11, 2014 at 01:48:12PM +0100, Antonio Quartulli wrote:
>> From: Antonio Quartulli <antonio@open-mesh.com>
>>
>> when batman-adv is asked to estimate/compute the throughput
>> of an interface, but it fails for whatever reason, then the
>> value in this attribute is used
>>
>> Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
>> ---
>> bat_v.c | 3 +++
>> main.h | 7 +++++++
>> sysfs.c | 7 +++++++
>> types.h | 1 +
>> 4 files changed, 18 insertions(+)
>>
>> diff --git a/bat_v.c b/bat_v.c
>> index d5457b3..3aa42ec 100644
>> --- a/bat_v.c
>> +++ b/bat_v.c
>> @@ -75,6 +75,9 @@ static struct batadv_algo_ops batadv_batman_v __read_mostly = {
>>
>> int batadv_v_mesh_init(struct batadv_priv *bat_priv)
>> {
>> + atomic_set(&bat_priv->bat_v.base_throughput,
>> + BATADV_DEFAULT_BASE_THROUGHPUT);
>> +
>> return batadv_v_ogm_init(bat_priv);
>> }
>>
>> diff --git a/main.h b/main.h
>> index 47fb9ed..5699c9f 100644
>> --- a/main.h
>> +++ b/main.h
>> @@ -33,6 +33,13 @@
>> #define BATADV_MAX_METRIC 0xFFFFFFFF
>> #define BATADV_JITTER 20
>>
>> +/**
>> + * BATADV_DEFAULT_BASE_THROUGHPUT - default value used as throughput for
>> + * hard_ifaces for which it is not possible to measure/estimate the real one.
>> + * Value is expressed in Mbps/10
>
> Mbps/10 is a rather odd unit. How about just Kbps?

This is the unit used in cfg/mac80211 because most of the rates are
either in the form of XX.0Mbps of XX.YMbps (so just one decimal number
needs to be saved).
Moreover I thought that having an higher precision is not very useful
because the routing decision cannot be taken on such a fine grained value.
Actually the originator table prints the metric in Mbps (XX.YMbps).

Do you think we should really go for the Kbps? this means losing one
order of magnitude on the highest value we can store (yeah, it's large
enough right now..but in the future who knows!)

Cheers,

--
Antonio Quartulli

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