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

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

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).


> all interesting places are called under rtnl already...
> 
>> Why is not possible to protect the list with a simple spinlock ? so we
>> can call spin_lock_bh when we are in interrupt handler.
> 
> see my old patch with a locking rules :)
> 
> By the way, I have forgotten to mention, that the original patch works
> from 2004 for OpenVz :)
> 
> Regards,
>     Den
> 


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