From owner-svn-src-all@freebsd.org Wed May 1 07:28:11 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E810515928E8; Wed, 1 May 2019 07:28:10 +0000 (UTC) (envelope-from slava.shwartsman@gmail.com) Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 74D5A8FDA7; Wed, 1 May 2019 07:28:09 +0000 (UTC) (envelope-from slava.shwartsman@gmail.com) Received: by mail-wm1-f66.google.com with SMTP id o25so6307627wmf.5; Wed, 01 May 2019 00:28:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:subject:from:to:references:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=KsIG70QEzPib2ajR8JxPLUGaPyK7qQCfqzwojcXhN6o=; b=HmZUo4SsA7Ms4PGT8zii5DeI/M98Ej/K3i13kNOBwa7H23lTkiIE2w2lBpWO7abXbK Uf1vtdSwvcGjRx1jreFY1wNdAZSmLgFyOOHitMUWgFffzFvj9KBRc1IVS6xB69pQSCSN D5Et/udvGq4NH9ucsiop5xCeRJTEyQofK3DlJIGNuh8MyaQEKoHhcV+AlCirPHdpmcwl zq7L+SXAQP6pRMjSJtphTAzYTaoimcHXvmiVYzxhNYm8Pr16lxQGojTq/vY4icgDUbLT hSYbmcsdi1jL8MDj6jpEHXornnvA41y7abDQGS6ms7GlbkWYSWXuZSMXgr1b1a0pnLny yi4Q== X-Gm-Message-State: APjAAAXMwkfmiDILlJBCMlv8NLSeJryi6Z2OzNS92myvl1SrTF0LobP4 ZUv/NDEaPRTmbMeO5A2u0sH2jqCI X-Google-Smtp-Source: APXvYqxFGsQZFI5R8VOOUG1x7dvH1aZ3iQuuq2LxA8UizZLMWe2jXvGf0X+zxS8cpZOIQHFsO27lsw== X-Received: by 2002:a05:600c:2506:: with SMTP id d6mr3251685wma.106.1556695687584; Wed, 01 May 2019 00:28:07 -0700 (PDT) Received: from [10.223.3.125] ([193.47.165.251]) by smtp.gmail.com with ESMTPSA id d3sm6720116wmf.46.2019.05.01.00.28.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 May 2019 00:28:07 -0700 (PDT) Reply-To: slavash@FreeBSD.org Subject: Re: svn commit: r341586 - head/sys/dev/mlx5/mlx5_en From: Slava Shwartsman To: John Baldwin , Hans Petter Selasky , "Andrey V. Elsukov" , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201812051425.wB5EP38T004562@repo.freebsd.org> <7cea5305-4136-a0b6-487b-51307b1c6db9@FreeBSD.org> <123654bf-59f7-1db8-55ce-36306bdac43d@FreeBSD.org> <67b638e0-8e6f-f960-b263-62eed8ce28b7@FreeBSD.org> <0e80cb1d-20b9-5b8c-330e-5f64a603ff10@FreeBSD.org> Message-ID: <737bfa62-eb3e-7c48-6356-0e0b76bb0593@FreeBSD.org> Date: Wed, 1 May 2019 10:28:05 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <0e80cb1d-20b9-5b8c-330e-5f64a603ff10@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 74D5A8FDA7 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of slavashwartsman@gmail.com designates 209.85.128.66 as permitted sender) smtp.mailfrom=slavashwartsman@gmail.com X-Spamd-Result: default: False [-2.47 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; HAS_REPLYTO(0.00)[slavash@FreeBSD.org]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; REPLYTO_ADDR_EQ_FROM(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; RCVD_COUNT_THREE(0.00)[3]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; FORGED_SENDER(0.30)[slavash@FreeBSD.org,slavashwartsman@gmail.com]; IP_SCORE(-1.23)[ipnet: 209.85.128.0/17(-3.85), asn: 15169(-2.24), country: US(-0.06)]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; MID_RHS_MATCH_FROM(0.00)[]; TAGGED_FROM(0.00)[]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_NEQ_ENVFROM(0.00)[slavash@FreeBSD.org,slavashwartsman@gmail.com]; FROM_HAS_DN(0.00)[]; NEURAL_SPAM_SHORT(0.77)[0.771,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; DMARC_NA(0.00)[FreeBSD.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[66.128.85.209.list.dnswl.org : 127.0.5.0]; RCVD_TLS_LAST(0.00)[] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 May 2019 07:28:11 -0000 On 01-May-19 10:09, Slava Shwartsman wrote: > > > On 30-Apr-19 00:14, John Baldwin wrote: >> On 4/25/19 12:10 AM, Slava Shwartsman wrote: >>> >>> >>> On 17-Apr-19 00:28, John Baldwin wrote: >>>> On 4/16/19 8:32 AM, Hans Petter Selasky wrote: >>>>> On 4/16/19 4:39 PM, Andrey V. Elsukov wrote: >>>>>> On 05.12.2018 17:25, Slava Shwartsman wrote: >>>>>>> Author: slavash >>>>>>> Date: Wed Dec  5 14:25:03 2018 >>>>>>> New Revision: 341586 >>>>>>> URL: https://svnweb.freebsd.org/changeset/base/341586 >>>>>>> >>>>>>> Log: >>>>>>>      mlx5en: Implement backpressure indication. >>>>>>>      The backpressure indication is implemented using an >>>>>>> unlimited rate type of >>>>>>>      mbuf send tag. When the upper layers typically the socket >>>>>>> layer has obtained such >>>>>>>      a tag, it can then query the destination driver queue for >>>>>>> the current >>>>>>>      amount of space available in the send queue. >>>>>>>      A single mbuf send tag may be referenced multiple times and >>>>>>> a refcount has been added >>>>>>>      to the mlx5e_priv structure to track its usage. Because the >>>>>>> send tag resides >>>>>>>      in the mlx5e_channel structure, there is no need to wait for >>>>>>> refcounts to reach >>>>>>>      zero until the mlx4en(4) driver is detached. The channels >>>>>>> structure is persistant >>>>>>>      during the lifetime of the mlx5en(4) driver it belongs to >>>>>>> and can so be accessed >>>>>>>      without any need of synchronization. >>>>>>>      The mlx5e_snd_tag structure was extended to contain a type >>>>>>> field, because there are now >>>>>>>      two different tag types which end up in the driver which >>>>>>> need to be distinguished. >>>>>>>      Submitted by:   hselasky@ >>>>>>>      Approved by:    hselasky (mentor) >>>>>>>      MFC after:      1 week >>>>>>>      Sponsored by:   Mellanox Technologies >>>>>>> @@ -587,27 +609,33 @@ mlx5e_xmit(struct ifnet *ifp, struct mbuf *mb) >>>>>>>         struct mlx5e_sq *sq; >>>>>>>         int ret; >>>>>>> -    sq = mlx5e_select_queue(ifp, mb); >>>>>>> -    if (unlikely(sq == NULL)) { >>>>>>> -#ifdef RATELIMIT >>>>>>> -        /* Check for route change */ >>>>>>> -        if (mb->m_pkthdr.snd_tag != NULL && >>>>>>> -            mb->m_pkthdr.snd_tag->ifp != ifp) { >>>>>>> +    if (mb->m_pkthdr.snd_tag != NULL) { >>>>>>> +        sq = mlx5e_select_queue_by_send_tag(ifp, mb); >>>>>>> +        if (unlikely(sq == NULL)) { >>>>>>> +            /* Check for route change */ >>>>>>> +            if (mb->m_pkthdr.snd_tag->ifp != ifp) { >>>>>>> +                /* Free mbuf */ >>>>>>> +                m_freem(mb); >>>>>>> + >>>>>>> +                /* >>>>>>> +                 * Tell upper layers about route >>>>>>> +                 * change and to re-transmit this >>>>>>> +                 * packet: >>>>>>> +                 */ >>>>>>> +                return (EAGAIN); >>>>>>> +            } >>>>>> >>>>>> Hi, >>>>>> >>>>>> I just discovered something strange and found that this commit is the >>>>>> cause. >>>>>> The test system has mlx5en 100G interface. It has two vlans: >>>>>> vlan500 and >>>>>> vlan100. >>>>>> Via vlan500 it receives some packets flows. Then it routes these >>>>>> packets >>>>>> into vlan100. >>>>>> But packets are dropped in mlx5e_xmit() with EAGAIN error code. >>>>>> >>>>>> # dtrace -n 'fbt::ip6_output:return {printf("%d", arg1);}' >>>>>> dtrace: description 'fbt::ip6_output:return ' matched 1 probe >>>>>> CPU     ID                    FUNCTION:NAME >>>>>>     23  54338                ip6_output:return 35 >>>>>>     16  54338                ip6_output:return 35 >>>>>>     21  54338                ip6_output:return 35 >>>>>>     22  54338                ip6_output:return 35 >>>>>>     24  54338                ip6_output:return 35 >>>>>>     23  54338                ip6_output:return 35 >>>>>>     14  54338                ip6_output:return 35 >>>>>> ^C >>>>>> >>>>>> # dtrace -n 'fbt::mlx5e_xmit:return {printf("%d", arg1);}' >>>>>> dtrace: description 'fbt::mlx5e_xmit:return ' matched 1 probe >>>>>> CPU     ID                    FUNCTION:NAME >>>>>>     16  69030                mlx5e_xmit:return 35 >>>>>>     23  69030                mlx5e_xmit:return 35 >>>>>>     26  69030                mlx5e_xmit:return 35 >>>>>>     25  69030                mlx5e_xmit:return 35 >>>>>>     24  69030                mlx5e_xmit:return 35 >>>>>>     21  69030                mlx5e_xmit:return 35 >>>>>>     26  69030                mlx5e_xmit:return 35 >>>>>> ^C >>>>>> >>>>>> The kernel config is GENERIC. >>>>>> 13.0-CURRENT #9 r345758+82f3d57(svn_head)-dirty >>>>>> >>>>> >>>>> Hi, >>>>> >>>>> This might be a case where rcvif in the mbuf's pktheader is not >>>>> cleared >>>>> before the packet is fed back on the wire. >>>>> >>>>> John Baldwin is working on the send tags implementation, to eliminate >>>>> the EAGAIN handling in the network drivers. >>>> >>>> I will try to push this branch sooner then since it affects more >>>> than just >>>> TLS.  Part of the change includes a new flag we can use to assert >>>> that we >>> Thanks John! >>>> aren't just getting a stale rcvif (though there are also now >>>> assertions in >>>> ip_output that should catch this case I think). >>>> >>> >>> >>> >>> Hi Andrey, >>> >>> Yes, we were able to reproduce this issue in house. If you don't mind, I >>> prefer to wait for John's update - where he eliminates the EAGAIN >>> handling in the network drivers. >> >> I have rebased the branch for this, but for now it will just panic sooner >> I believe by tripping an assertion.  Can you grab the diff (or just >> the branch) >> from the 'send_tags' branch at github/bsdjhb/freebsd and reproduce >> under a >> kernel with INVARIANTS?  I think we will have to explicitly clear the >> 'rcvif' >> pointer somewhere, but I want to see what the stack trace looks like >> so I can >> think about the "right" place to clear it. >> > > Hi John, > > I grabbed your branch (which doesn't build BTW due to libbe(3): Fix > mis-application of patch (SHLIBDIR) so I just reverted it). > > The kernel doesn't panic in this scenario - it just that the packets are > being dropped. So I added a kdb_backtrace right before the return > (EAGAIN) in mlx5e_xmit: > > KDB: stack backtrace: > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > 0xfffffe0000547d90 > mlx5e_xmit() at mlx5e_xmit+0x3d/frame 0xfffffe0000548160 > vlan_transmit() at vlan_transmit+0xdc/frame 0xfffffe00005481d0 > ether_output_frame() at ether_output_frame+0xa2/frame 0xfffffe0000548200 > ether_output() at ether_output+0x689/frame 0xfffffe00005482a0 > ip_output() at ip_output+0x13a4/frame 0xfffffe00005483f0 > ip_forward() at ip_forward+0x344/frame 0xfffffe00005484b0 > ip_input() at ip_input+0x7f5/frame 0xfffffe0000548560 > netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe00005485d0 > ether_demux() at ether_demux+0x147/frame 0xfffffe0000548600 > ether_nh_input() at ether_nh_input+0x403/frame 0xfffffe0000548660 > netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe00005486d0 > ether_input() at ether_input+0x73/frame 0xfffffe0000548700 > vlan_input() at vlan_input+0x1e7/frame 0xfffffe0000548750 > ether_demux() at ether_demux+0x12d/frame 0xfffffe0000548780 > ether_nh_input() at ether_nh_input+0x403/frame 0xfffffe00005487e0 > netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe0000548850 > ether_input() at ether_input+0x73/frame 0xfffffe0000548880 > mlx5e_rx_cq_comp() at mlx5e_rx_cq_comp+0x8b4/frame 0xfffffe00005489a0 > mlx5_cq_completion() at mlx5_cq_completion+0x5e/frame 0xfffffe00005489d0 > mlx5_msix_handler() at mlx5_msix_handler+0x1ba/frame 0xfffffe0000548a10 > ithread_loop() at ithread_loop+0x187/frame 0xfffffe0000548a70 > fork_exit() at fork_exit+0x84/frame 0xfffffe0000548ab0 > fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0000548ab0 > --- trap 0, rip = 0, rsp = 0, rbp = 0 --- > > > Please ping me if you want me to try anything else. > > > Slava My bad - tested with master. Re-testing now. Slava