netdev - Re: [PATCH net-next 0/7] net: speedup netns create/delete time

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Message-ID: <1505863213.29839.79.camel@edumazet-glaptop3.roam.corp.google.com>
Date:   Tue, 19 Sep 2017 16:20:13 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     David Miller <davem@...emloft.net>
Cc:     edumazet@...gle.com, netdev@...r.kernel.org, ebiederm@...ssion.com
Subject: Re: [PATCH net-next 0/7] net: speedup netns create/delete time

On Tue, 2017-09-19 at 16:02 -0700, David Miller wrote:
> From: Eric Dumazet <edumazet@...gle.com>
> Date: Mon, 18 Sep 2017 12:07:26 -0700
> 
> > When rate of netns creation/deletion is high enough,
> > we observe softlockups in cleanup_net() caused by huge list
> > of netns and way too many rcu_barrier() calls.
> > 
> > This patch series does some optimizations in kobject,
> > and add batching to tunnels so that netns dismantles are
> > less costly.
> > 
> > IPv6 addrlabels also get a per netns list, and tcp_metrics
> > also benefit from batch flushing.
> > 
> > This gives me one order of magnitude gain.
> > (~50 ms -> ~5 ms for one netns create/delete pair)
> 
> I like it.
> 
> Please address the feedback about using skb_put_data() and
> resubmit.

Sure, will also remove a spurious // comment I accidentally left in
patch 7/7.