From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51004 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724AbdHHXaF (ORCPT ); Tue, 8 Aug 2017 19:30:05 -0400 Subject: Patch "tcp_bbr: remove sk_pacing_rate=0 transient during init" has been added to the 4.9-stable tree To: ncardwell@google.com, davem@davemloft.net, edumazet@google.com, gregkh@linuxfoundation.org, soheil@google.com, ycheng@google.com Cc: , From: Date: Tue, 08 Aug 2017 16:30:03 -0700 Message-ID: <15022350034793@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tcp_bbr: remove sk_pacing_rate=0 transient during init to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp_bbr-remove-sk_pacing_rate-0-transient-during-init.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Tue Aug 8 16:27:53 PDT 2017 From: Neal Cardwell Date: Fri, 14 Jul 2017 17:49:24 -0400 Subject: tcp_bbr: remove sk_pacing_rate=0 transient during init From: Neal Cardwell [ Upstream commit 1d3648eb5d1fe9ed3d095ed8fa19ad11ca4c8bc0 ] Fix a corner case noticed by Eric Dumazet, where BBR's setting sk->sk_pacing_rate to 0 during initialization could theoretically cause packets in the sending host to hang if there were packets "in flight" in the pacing infrastructure at the time the BBR congestion control state is initialized. This could occur if the pacing infrastructure happened to race with bbr_init() in a way such that the pacer read the 0 rather than the immediately following non-zero pacing rate. Fixes: 0f8782ea1497 ("tcp_bbr: add BBR congestion control") Reported-by: Eric Dumazet Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_bbr.c | 1 - 1 file changed, 1 deletion(-) --- a/net/ipv4/tcp_bbr.c +++ b/net/ipv4/tcp_bbr.c @@ -808,7 +808,6 @@ static void bbr_init(struct sock *sk) minmax_reset(&bbr->bw, bbr->rtt_cnt, 0); /* init max bw to 0 */ - sk->sk_pacing_rate = 0; /* force an update of sk_pacing_rate */ bbr_init_pacing_rate_from_rtt(sk); bbr->restore_cwnd = 0; Patches currently in stable-queue which might be from ncardwell@google.com are queue-4.9/tcp_bbr-remove-sk_pacing_rate-0-transient-during-init.patch queue-4.9/tcp_bbr-introduce-bbr_bw_to_pacing_rate-helper.patch queue-4.9/tcp_bbr-introduce-bbr_init_pacing_rate_from_rtt-helper.patch queue-4.9/tcp_bbr-init-pacing-rate-on-first-rtt-sample.patch queue-4.9/tcp_bbr-cut-pacing-rate-only-if-filled-pipe.patch