From nobody Sun Sep 26 00:53:15 2021 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 66AA117DA7E1 for ; Sun, 26 Sep 2021 00:53:25 +0000 (UTC) (envelope-from freebsd@omnilan.de) Received: from mx0.gentlemail.de (mx0.gentlemail.de [IPv6:2a00:e10:2800::a130]) (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 did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4HH6hN16nLz4R9f; Sun, 26 Sep 2021 00:53:24 +0000 (UTC) (envelope-from freebsd@omnilan.de) Received: from mh0.gentlemail.de (ezra.dcm1.omnilan.net [IPv6:2a00:e10:2800:0:0:0:0:a135]) by mx0.gentlemail.de (8.15.2/8.15.2) with ESMTP id 18Q0rGUB037930; Sun, 26 Sep 2021 02:53:16 +0200 (CEST) (envelope-from freebsd@omnilan.de) X-Authentication-Warning: mx0.gentlemail.de: Host ezra.dcm1.omnilan.net [IPv6:2a00:e10:2800:0:0:0:0:a135] claimed to be mh0.gentlemail.de Received: from titan.inop.mo1.omnilan.net (s1.omnilan.de [217.91.127.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mh0.gentlemail.de (Postfix) with ESMTPSA id 0B2D2EAA; Sun, 26 Sep 2021 02:53:15 +0200 (CEST) Subject: Re: git: 1a72c3d76aea - stable/13 - e1000: always enable PCSD when RSS hashing [Was: TCP6 regression for MTU path on stable/13] From: Harry Schmalzbauer To: Kevin Bowling References: <8e4f78e5-0717-8002-5364-44df5c8d7dad@omnilan.de> <36d9d998-c484-a4f6-6c62-c6ec103aeb33@yandex.ru> <14f7348c-a11f-9ae8-8a4e-77e0333ba478@omnilan.de> Organization: OmniLAN Cc: "Andrey V. Elsukov" , "net@FreeBSD.org" Message-ID: <57df3182-a7ec-112c-c8d8-a8faa21a97a8@omnilan.de> Date: Sun, 26 Sep 2021 02:53:15 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 In-Reply-To: <14f7348c-a11f-9ae8-8a4e-77e0333ba478@omnilan.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Rspamd-Queue-Id: 4HH6hN16nLz4R9f X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of freebsd@omnilan.de designates 2a00:e10:2800::a130 as permitted sender) smtp.mailfrom=freebsd@omnilan.de X-Spamd-Result: default: False [-1.31 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; DMARC_NA(0.00)[omnilan.de]; NEURAL_SPAM_SHORT(0.99)[0.994]; HAS_ORG_HEADER(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-0.999]; RCVD_TLS_LAST(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[yandex.ru,freebsd.org]; ASN(0.00)[asn:61157, ipnet:2a00:e10:2800::/38, country:DE]; MID_RHS_MATCH_FROM(0.00)[] X-ThisMailContainsUnwantedMimeParts: N Am 13.09.2021 um 13:18 schrieb Harry Schmalzbauer: > Am 13.09.2021 um 12:37 schrieb Andrey V. Elsukov: >> 12.09.2021 14:12, Harry Schmalzbauer пишет: >>> Will try to further track it down, but in case anybody has an idea, >>> what >>> change during the last view months in stable/13 could have caused this >>> real-world problem regarding resulting TCP6 throughput, I'm happy to >>> start testing at that point. >> >> Hi, >> >> Take a look at: >> >>    https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255749 >>    https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248005 >> >> does the problem described in these PRs is the same as yours? > > Hi, thank you very much for your attention! > Most likely these are unrelated to the regression I'm suffering from, > because these affect 13-release and earlier. > Mine arose during the last months. > And it seems not to be a jumbo frame problem. : > Hope to get back to you soon with more info. Since the setup was hard to replicate, it took some time. Here's the commit, causing the heavy IPv6 performance drop with Intel Powerville and IPv6: > The branch stable/13 has been updated by kbowling (ports committer): > > URL: > https://cgit.FreeBSD.org/src/commit/?id=1a72c3d76aeafe4422ff20f81c4142efb983b7d7 > > commit 1a72c3d76aeafe4422ff20f81c4142efb983b7d7 > Author:     Kevin Bowling > AuthorDate: 2021-08-16 17:17:34 +0000 > Commit:     Kevin Bowling > CommitDate: 2021-08-23 16:23:43 +0000 > >     e1000: always enable PCSD when RSS hashing > >     To enable RSS hashing in the NIC, the PCSD bit must be set. > >     By default, this is never set when RXCSUM is disabled - which >     causes problems higher up in the stack. > >     While here improve the RXCSUM flag assignments when enabling or >     disabling IFCAP_RXCSUM. > >     See also: > https://lists.freebsd.org/pipermail/freebsd-current/2020-May/076148.html > >     Reviewed by:    markj, Franco Fichtner , >                     Stephan de Wit >     Obtained from:  OPNsense >     MFC after:      1 week >     Differential Revision:  https://reviews.freebsd.org/D31501 >     Co-authored-by: Stephan de Wit >     Co-authored-by: Franco Fichtner > >     (cherry picked from commit 69e8e8ea3d4be9da6b5bc904a444b51958128ff5) > : Noticed and successfully (double-{a8446d412+f72cdea25}) falsified with i350 Powerville, device=0x1521. *Reverting git: 1a72c3d76aea against today's stable/13(-f72cdea25-dirty) sloves the issue, which seems to be IPv6 related only.* (kernel  a8446d412 from 21/09/25 shows issue, reverting this commit solves it with old kernel too) Very brief check against IPv4 on identical paths seems to be unaffected, but I can't guarantee since v4 isn't in use (where I 1st noticed and suffer from) and I just did one comparing in order to narrow down (asymmetric FIB setup regarding inet and inet6). What this made complicated: ng_brige(4), mpd5/pppoe,ppt,bhyve are involved as well (and vlan(4), lagg(4) and vtnet(4), etc.), but it seems to be just a e1000 driver issue. There were many changes/iprovements/cleanups between July and September, but I tracked it down as root cause for my IPv6 issue (performance dropping from 33MB/s to <=0.3MB/s). That beeing said, it was hard to find the time replicating the setup, and I have nothing for a solution.  Haven't semantically checked anything yet and didn't do any tests beside my single IPv6 performance test.  Contrary to my first suspicion, at least in my clone-lab, it isn't MTU/jumbo frame related, just plain e1000/i350 IPv6 regression. Happy to test anything, can test-drive swiftly but without further diag during work days. Thanks, -harry