From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v4 net-next 00/19] inet: frags: bring rhashtables to IP
 defrag
Date: Sat, 31 Mar 2018 23:25:58 -0400 (EDT)
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From: Eric Dumazet <edumazet@google.com>
Date: Sat, 31 Mar 2018 12:58:41 -0700

> IP defrag processing is one of the remaining problematic layer in linux.
> 
> It uses static hash tables of 1024 buckets, and up to 128 items per bucket.
> 
> A work queue is supposed to garbage collect items when host is under memory
> pressure, and doing a hash rebuild, changing seed used in hash computations.
> 
> This work queue blocks softirqs for up to 25 ms when doing a hash rebuild,
> occurring every 5 seconds if host is under fire.
> 
> Then there is the problem of sharing this hash table for all netns.
> 
> It is time to switch to rhashtables, and allocate one of them per netns
> to speedup netns dismantle, since this is a critical metric these days.
> 
> Lookup is now using RCU, and 64bit hosts can now provision whatever amount
> of memory needed to handle the expected workloads.
 ...

Series applied, thanks Eric.