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 :)

So you prefer to have multiple timers flushing a portion of a shared 
routing cache ?

It is not impossible I already tryed that for ipv6. it will just touch 
much more files.

If we want, at all costs, to have the routing cache flushed per 
namespace, I am much more favorable to have a timer per namespace than 
using the algorithm you sent previously.