From: David Miller <davem@davemloft.net>
To: edumazet@google.com
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net-next] net: use indirect call wrappers for skb_copy_datagram_iter()
Date: Wed, 25 Mar 2020 11:31:02 -0700 (PDT) [thread overview]
Message-ID: <20200325.113102.661246567769402013.davem@davemloft.net> (raw)
In-Reply-To: <20200325022321.21944-1-edumazet@google.com>
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 24 Mar 2020 19:23:21 -0700
> TCP recvmsg() calls skb_copy_datagram_iter(), which
> calls an indirect function (cb pointing to simple_copy_to_iter())
> for every MSS (fragment) present in the skb.
>
> CONFIG_RETPOLINE=y forces a very expensive operation
> that we can avoid thanks to indirect call wrappers.
>
> This patch gives a 13% increase of performance on
> a single flow, if the bottleneck is the thread reading
> the TCP socket.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied, thanks Eric.
prev parent reply other threads:[~2020-04-02 14:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 2:23 [PATCH net-next] net: use indirect call wrappers for skb_copy_datagram_iter() Eric Dumazet
2020-03-25 4:22 ` Eric Dumazet
2020-03-25 11:52 ` Paolo Abeni
2020-03-25 14:55 ` Willem de Bruijn
2020-03-25 16:00 ` Paolo Abeni
2020-03-25 16:07 ` Eric Dumazet
2020-03-25 16:24 ` Paolo Abeni
[not found] ` <CANn89iKotU9Tkd6KBgyicHFV72K9gZ+eeKwkPU097=gZZYCjrA@mail.gmail.com>
2020-03-25 16:46 ` Eric Dumazet
2020-03-25 20:58 ` Willem de Bruijn
2020-03-25 15:14 ` Eric Dumazet
2020-03-25 18:31 ` David Miller [this message]
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