From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] AF_UNIX: Implement SO_TIMESTAMP and SO_TIMETAMPNS on Unix sockets Date: Mon, 04 Oct 2010 18:41:44 +0200 Message-ID: <1286210504.18293.370.camel@edumazet-laptop> References: <1286206706-25733-1-git-send-email-alban.crequy@collabora.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Lennart Poettering , "David S. Miller" , Stephen Hemminger , Cyrill Gorcunov , Alexey Dobriyan , linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Alban Crequy Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:58184 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756125Ab0JDQl6 (ORCPT ); Mon, 4 Oct 2010 12:41:58 -0400 In-Reply-To: <1286206706-25733-1-git-send-email-alban.crequy@collabora.co.uk> Sender: netdev-owner@vger.kernel.org List-ID: Le lundi 04 octobre 2010 =C3=A0 16:38 +0100, Alban Crequy a =C3=A9crit = : > Userspace applications can already request to receive timestamps with= : > setsockopt(sockfd, SOL_SOCKET, SO_TIMESTAMP, ...) >=20 > Although setsockopt() returns zero (success), timestamps are not adde= d to the > ancillary data. This patch fixes that. >=20 > Signed-off-by: Alban Crequy > --- > net/unix/af_unix.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) >=20 > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index 617bea4..142ccea 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -1697,6 +1697,8 @@ static int unix_dgram_recvmsg(struct kiocb *ioc= b, struct socket *sock, > if (err) > goto out_free; > =20 > + sock_recv_timestamp(msg, sk, skb); > + > if (!siocb->scm) { > siocb->scm =3D &tmp_scm; > memset(&tmp_scm, 0, sizeof(tmp_scm)); > @@ -1877,6 +1879,8 @@ static int unix_stream_recvmsg(struct kiocb *io= cb, struct socket *sock, > copied +=3D chunk; > size -=3D chunk; > =20 > + sock_recv_timestamp(msg, sk, skb); > + > /* Mark read part of skb as used */ > if (!(flags & MSG_PEEK)) { > skb_pull(skb, chunk); Are you sure its needed for unix_stream case ? We dont do this for TCP for example, only for datagrams. As shown in the past, sock_recv_timestamp() is a bit expensive because it takes care of many possible options. It would be better to use in AF_UNIX case (only software timestamps) : Solution 1)=20 if (sock_flag(sk, SOCK_RCVTSTAMP)) __sock_recv_timestamp(msg, sk, skb); Solution 2)=20 Or something already used elsewhere since 2.6.35 and commit 767dd03369ac1 (net: speedup sock_recv_ts_and_drops()) : sock_recv_ts_and_drops(msg, sk, skb); I would vote for the 1) solution