From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: yuvalm@mellanox.com, ktkhai@virtuozzo.com,
yoshfuji@linux-ipv6.org, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] ip6mr: remove synchronize_rcu() in favor of SOCK_RCU_FREE
Date: Wed, 07 Mar 2018 18:14:18 -0500 (EST) [thread overview]
Message-ID: <20180307.181418.1356901556042128422.davem@davemloft.net> (raw)
In-Reply-To: <1520440999.109662.48.camel@gmail.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 07 Mar 2018 08:43:19 -0800
> From: Eric Dumazet <edumazet@google.com>
>
> Kirill found that recently added synchronize_rcu() call in
> ip6mr_sk_done()
> was slowing down netns dismantle and posted a patch to use it only if
> the socket
> was found.
>
> I instead suggested to get rid of this call, and use instead
> SOCK_RCU_FREE
>
> We might later change IPv4 side to use the same technique and unify
> both stacks. IPv4 does not use synchronize_rcu() but has a call_rcu()
> that could be replaced by SOCK_RCU_FREE.
>
> Tested:
> time for i in {1..1000}; do unshare -n /bin/false;done
>
> Before : real 7m18.911s
> After : real 10.187s
>
> Fixes: 8571ab479a6e ("ip6mr: Make mroute_sk rcu-based")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> Cc: Yuval Mintz <yuvalm@mellanox.com>
Looks great, applied, thanks everyone.
prev parent reply other threads:[~2018-03-07 23:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-06 16:24 [PATCH RESEND net-next] net: Do synchronize_rcu() in ip6mr_sk_done() only if this is needed Kirill Tkhai
2018-03-06 16:50 ` Eric Dumazet
2018-03-06 16:58 ` Eric Dumazet
2018-03-06 17:20 ` Eric Dumazet
2018-03-07 9:22 ` Kirill Tkhai
2018-03-07 9:32 ` Kirill Tkhai
2018-03-07 13:51 ` Yuval Mintz
2018-03-07 14:22 ` Eric Dumazet
2018-03-07 16:43 ` [PATCH net-next] ip6mr: remove synchronize_rcu() in favor of SOCK_RCU_FREE Eric Dumazet
2018-03-07 22:11 ` Kirill Tkhai
2018-03-07 23:14 ` David Miller [this message]
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