From owner-svn-src-stable-12@freebsd.org Thu Jun 4 21:02:24 2020 Return-Path: Delivered-To: svn-src-stable-12@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id AC282331FE0; Thu, 4 Jun 2020 21:02:24 +0000 (UTC) (envelope-from rscheff@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49dJBS4BGqz3fMQ; Thu, 4 Jun 2020 21:02:24 +0000 (UTC) (envelope-from rscheff@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 8827A25D55; Thu, 4 Jun 2020 21:02:24 +0000 (UTC) (envelope-from rscheff@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 054L2OJ9094477; Thu, 4 Jun 2020 21:02:24 GMT (envelope-from rscheff@FreeBSD.org) Received: (from rscheff@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 054L2O5W094476; Thu, 4 Jun 2020 21:02:24 GMT (envelope-from rscheff@FreeBSD.org) Message-Id: <202006042102.054L2O5W094476@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rscheff set sender to rscheff@FreeBSD.org using -f From: Richard Scheffenegger Date: Thu, 4 Jun 2020 21:02:24 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r361808 - stable/12/sys/netinet/cc X-SVN-Group: stable-12 X-SVN-Commit-Author: rscheff X-SVN-Commit-Paths: stable/12/sys/netinet/cc X-SVN-Commit-Revision: 361808 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable-12@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for only the 12-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Jun 2020 21:02:24 -0000 Author: rscheff Date: Thu Jun 4 21:02:24 2020 New Revision: 361808 URL: https://svnweb.freebsd.org/changeset/base/361808 Log: MFC rS361348: DCTCP: update alpha only once after loss recovery. In mixed ECN marking and loss scenarios it was found, that the alpha value of DCTCP is updated two times. The second update happens with freshly initialized counters indicating to ECN loss. Overall this leads to alpha not adjusting as quickly as expected to ECN markings, and therefore lead to excessive loss. Reported by: Cheng Cui Reviewed by: chengc_netapp.com, rrs, tuexen (mentor) Approved by: tuexen (mentor), rgrimes (mentor, blanket) Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D24817 Modified: stable/12/sys/netinet/cc/cc_dctcp.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/cc/cc_dctcp.c ============================================================================== --- stable/12/sys/netinet/cc/cc_dctcp.c Thu Jun 4 20:48:57 2020 (r361807) +++ stable/12/sys/netinet/cc/cc_dctcp.c Thu Jun 4 21:02:24 2020 (r361808) @@ -154,10 +154,8 @@ dctcp_ack_received(struct cc_var *ccv, uint16_t type) * Update the fraction of marked bytes at the end of * current window size. */ - if ((IN_FASTRECOVERY(CCV(ccv, t_flags)) && - SEQ_GEQ(ccv->curack, CCV(ccv, snd_recover))) || - (!IN_FASTRECOVERY(CCV(ccv, t_flags)) && - SEQ_GT(ccv->curack, dctcp_data->save_sndnxt))) + if (!IN_FASTRECOVERY(CCV(ccv, t_flags)) && + SEQ_GT(ccv->curack, dctcp_data->save_sndnxt)) dctcp_update_alpha(ccv); } else newreno_cc_algo.ack_received(ccv, type);