[Bridge] [PATCH net-next] net: bridge: update multicast stats from maybe_deliver()

Nikolay Aleksandrov nikolay at cumulusnetworks.com
Thu Apr 4 12:24:55 UTC 2019


On 04/04/2019 15:21, Pablo Neira Ayuso wrote:
> On Thu, Apr 04, 2019 at 03:02:19PM +0300, Nikolay Aleksandrov wrote:
>> On 04/04/2019 14:56, Pablo Neira Ayuso wrote:
>>> Simplify this code by updating bridge multicast stats from
>>> maybe_deliver().
>>>
>>> Note that commit 6db6f0eae605 ("bridge: multicast to unicast"), in case
>>> the port flag BR_MULTICAST_TO_UNICAST is set, never updates the previous
>>> port pointer, therefore it is always going to be different from the
>>> existing port in this deduplicated list iteration.
>>>
>>> Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
>>> ---
>>>  net/bridge/br_forward.c | 15 ++++-----------
>>>  1 file changed, 4 insertions(+), 11 deletions(-)
> 
> This is removing two branches, it is less code to maintain and easier
> to read than:
> 
>         if (prev == p)
> 

ack

>> This was intentional, the reason I didn't add that call to maybe_deliver() is to avoid
>> these checks for the standard unicast fast-path.  We need to avoid touching the mcast
>> cache lines (and checks) when using unicast.
> 
> maybe_deliver() is called from br_flood() and br_multicast_flood(),
> not the standard unicast fast-path.
> 

Oh right, I was thinking of should_deliver(), my bad.

> Thanks.
> 


Acked-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>


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