From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A87916F8EF for ; Tue, 3 Sep 2024 15:23:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725377000; cv=none; b=F7BLjqlvWDnNFn4K49z6nVC4lQTXFF32VEICdDP2HPvD6NLJzBN6RLRwWtKLFbly4+TWf6Vz1JV/KElnRmoiEjV+PHInIRaw8dykYg0K2bTFENxaIzLXEHPxu87CXgPWKbUJ4q4HMT0QiOOdD+LFrtafbWS6OrTr9PViZWWyrsY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725377000; c=relaxed/simple; bh=o8GI0Ak+/023ld+zCZQ1jH2Br85ZeDNO0Byay46FOPA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TJc1htv+3vDhCzO0rbVPeoyqVlmGtQSHLKItJap8lNw43vgkZM3uZR6O+b7UoCyw0Hh+CS9r2OmASpkJO/Gc7BDNJY54Xqkm5ulKezHya6Y9lDYqFuhhqEQIn5PhmXPNLh58a7SrlFHDdVbXXB8UqA8CzgRvdG8J+wZFH9xz4ns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WaxYtGWJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WaxYtGWJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A026C4CEC4; Tue, 3 Sep 2024 15:23:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725376999; bh=o8GI0Ak+/023ld+zCZQ1jH2Br85ZeDNO0Byay46FOPA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WaxYtGWJ0/KKy6URgk8LrmXaBsVtheGUvHnilInreypfvfHb52Rnu6qiy1OpoPoFT H6Tx5p5VFs+1LN5zEIp3p61IF7GndTCoBgxGa6QXLZjQGhH+P7Np4t/1omGrheE9wU 0a2e16IbgF/VMGBx79kBVtLiMGjkJEXlTCxmdM1h/l5NxQj3gA5KSHGvpVgvQcTLsd EHH2o6iEq6bAgLoJlQ9p2wJXvygf2Y0MctXkNMo432TNaoJB9fPSj9q7/p8fa/Ltm3 dgU6jF9qsSd4OQ4PSBqTyv3wSHtCIreWgLTAeXo0XENf1XxFEYu7TniSgJQmBUaZYB 0kYNPnttQ9UUg== Date: Tue, 3 Sep 2024 16:23:16 +0100 From: Simon Horman To: Vadim Fedorenko Cc: Willem de Bruijn , Jakub Kicinski , Paolo Abeni , David Ahern , Jason Xing , netdev@vger.kernel.org Subject: Re: [PATCH net-next v2 1/2] net_tstamp: add SCM_TS_OPT_ID to provide OPT_ID in control message Message-ID: <20240903152316.GB4792@kernel.org> References: <20240902130937.457115-1-vadfed@meta.com> <20240902183833.GK23170@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Sep 02, 2024 at 08:35:26PM +0100, Vadim Fedorenko wrote: > On 02/09/2024 19:38, Simon Horman wrote: > > On Mon, Sep 02, 2024 at 06:09:35AM -0700, Vadim Fedorenko wrote: > > > SOF_TIMESTAMPING_OPT_ID socket option flag gives a way to correlate TX > > > timestamps and packets sent via socket. Unfortunately, there is no way > > > to reliably predict socket timestamp ID value in case of error returned > > > by sendmsg. For UDP sockets it's impossible because of lockless > > > nature of UDP transmit, several threads may send packets in parallel. In > > > case of RAW sockets MSG_MORE option makes things complicated. More > > > details are in the conversation [1]. > > > This patch adds new control message type to give user-space > > > software an opportunity to control the mapping between packets and > > > values by providing ID with each sendmsg. This works fine for UDP > > > sockets only, and explicit check is added to control message parser. > > > > > > [1] https://lore.kernel.org/netdev/CALCETrU0jB+kg0mhV6A8mrHfTE1D1pr1SD_B9Eaa9aDPfgHdtA@mail.gmail.com/ > > > > > > Signed-off-by: Vadim Fedorenko > > > > ... > > > > > diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c > > > > ... > > > > > @@ -1543,10 +1546,15 @@ static int __ip6_append_data(struct sock *sk, > > > flags &= ~MSG_SPLICE_PAGES; > > > } > > > - hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP && > > > - READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID; > > > - if (hold_tskey) > > > - tskey = atomic_inc_return(&sk->sk_tskey) - 1; > > > + if (cork->tx_flags & SKBTX_ANY_TSTAMP && > > > + READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) { > > > + if (cork->flags & IPCORK_TS_OPT_ID) { > > > + tskey = cork->ts_opt_id; > > > + } else { > > > + tskey = atomic_inc_return(&sk->sk_tskey) - 1; > > > + hold_tskey = true; > > > > Hi Vadim, > > > > I think that hold_tskey also needs to be assigned a value in > > the cases where wither of the if conditions above are false. > > Hi Simon! > > Yes, you are right. I should probably init it with false to avoid > 'else' statement. Thanks, I agree that seems like a good approach.