Re: [PATCH] [NETNS49] support for per/namespace routing cache cleanup

[Benjamin Thery <benjamin.thery-6ktuUTfB/bM@public.gmane.org>]

Denis V. Lunev wrote:
> Benjamin Thery wrote:
>> Denis V. Lunev wrote:
>>> Daniel Lezcano wrote:
>>>> Oh, by the way, I forgot something important you spotted with the list
>>>> protected by the mutex.
>>>>
>>>> When looking at ipv6/fib_hash.c with Benjamin, we need to browse the
>>>> network namespaces list for the garbage collecting, but we are in an
>>>> interrupt handler, so I can not use rtnl_lock.
>>> where exactly....
>>
>> Actually, it is in net/ipv6/ip6_fib.c, in fib6_clean_all().
>>
>> fib6_clean_all() is called by fib6_run_gc() handler of the
>> ip6_fib_timer. If we don't want to have one such timer per net
>> namespace, in fib6_clean_all() we have to go through all net to clean
>> their own
>> fib_table_hash (using for_each_net() protected by rtnl_lock).
> 
> after careful thinking, one timer per/namespace looks better for me :)

Why? :)
Then you'll have to find a way pass the target net to fib6_run_gc() 
(the timer handler). current->nsproxy->net_ns won't work :)
One timer for all looked simpler to me.

Can there be an impact on performance if we have several GC timers
for the several netns running? 

Benjamin

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