Re: Some performance measurements on the FreeBSD network stack

>> This only helps if your flows aren't hitting the same rtentry.
>> Otherwise you still convoy on the lock for the rtentry itself to
>> increment and decrement the rtentry's reference count.
>
>
> The rtentry lock isn't obtained anymore.  While the rmlock read
> lock is held on the rtable the relevant information like ifp and
> such is copied out.  No later referencing possible.  In the end
> any referencing of an rtentry would be forbidden and the rtentry
> lock can be removed.  The second step can be optional though.

Can you point me to a tree where you've made these changes?

>>> i was wondering, is there a way (and/or any advantage) to use the
>>> fastforward code to look up the route for locally sourced packets ?
>>>
>>
>> If the number of peers is bounded then you can use the flowtable. Max
>> PPS is much higher bypassing routing lookup. However, it doesn't scale
>> to arbitrary flow numbers.
>
>
> In theory a rmlock-only lookup into a default-route only routing
> table would be faster than creating a flow table entry for every
> destination.  It a matter of churn though.  The flowtable isn't
> lockless in itself, is it?

It is. In a steady state where the working set of peers fits in the
table it should be just a simple hash of the ip and then a lookup.

-Kip
-- 
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