From: Eric Dumazet <eric.dumazet@gmail.com>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: David Miller <davem@davemloft.net>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
netdev@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next] net: init sk_cookie for inet socket
Date: Tue, 24 Apr 2018 05:37:13 -0700 [thread overview]
Message-ID: <45bfd7ce-ecfa-8a4d-b1ed-8914a6b90093@gmail.com> (raw)
In-Reply-To: <CALOAHbDajHPN9Z3TTWFBwpd1H16RVRRYYiUMrUELE3JxeZo+qw@mail.gmail.com>
On 04/24/2018 04:47 AM, Yafang Shao wrote:
>
> Could you pls. explain the issue to me ?
Just run a synflood test on your host, it will definitely show the atomic
consuming most cpu cycles in inet_reqsk_alloc(), because of huge contention
on a cache line shared by all cpus.
Performance is reduced from ~5 Mpps to ~3.8 Mpps with 16 RX queues on my host.
atomic64_inc_return(&sock_net(sk)->cookie_gen) was not meant to be used in the
normal case (when a socket cookie is not ever requested/needed)
prev parent reply other threads:[~2018-04-24 12:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-22 13:50 [PATCH net-next] net: init sk_cookie for inet socket Yafang Shao
2018-04-23 15:58 ` David Miller
2018-04-23 16:09 ` Eric Dumazet
2018-04-24 4:39 ` Yafang Shao
2018-04-24 11:41 ` Eric Dumazet
2018-04-24 11:47 ` Yafang Shao
2018-04-24 12:37 ` Eric Dumazet [this message]
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