From owner-svn-src-all@freebsd.org Wed May 1 08:06:07 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 75C371598AA5; Wed, 1 May 2019 08:06:07 +0000 (UTC) (envelope-from slava.shwartsman@gmail.com) Received: from mail-wr1-f65.google.com (mail-wr1-f65.google.com [209.85.221.65]) (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 025D96A889; Wed, 1 May 2019 08:06:05 +0000 (UTC) (envelope-from slava.shwartsman@gmail.com) Received: by mail-wr1-f65.google.com with SMTP id o4so11852778wra.3; Wed, 01 May 2019 01:06:05 -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=pYpzvyvmGs4c9zK5kbcxmuwABTB2cM9SVj3k4V1GTEc=; b=mB6LNcFZ6+nCNuqycex25hZzWz4EsK4S1/PWDK55o8uirR6R86Ox2vY4w6TDZl5Kx/ FfltUENRwuKfsZIcaQEWBFpO4HoIiiFu3oG1hEqRUJWo3UBBrya2guzubP8Xg1BuMZuj BDScFOOuhdP0cbUjyrJvEp9iOR95Rs12eo6HAtiMEIbZ8zjtwr3sAhSrT6AqWRDIe8hU EVn32wUNM4TFYyF6zzsKcKOq2yFZdymEJWhBjiHYv1RYEBN+kC9DpUPYjPsFwa11zdZu X+Z5b/2ejz7ZRsPJjE4J6Ia0wbPUlwFQQaQ+otAi7WxuXhLFMHexgTOOMBuCv2r0DLOj JkMA== X-Gm-Message-State: APjAAAXzShPTgy51s+yFEW2potKTcqIOI1iSJ+RT5EmBKniPIZVQtwkX 25UHdWevDcjo5L764Fa8AyppVgcP X-Google-Smtp-Source: APXvYqzt/8cvyaWEl4Fks1gLuC9gMca7xILJKY6V7KQhYykjC5Rpl2iQT58726REevZYtd7kM+GiXw== X-Received: by 2002:adf:dcc7:: with SMTP id x7mr12370052wrm.197.1556697958472; Wed, 01 May 2019 01:05:58 -0700 (PDT) Received: from [10.223.3.125] ([193.47.165.251]) by smtp.gmail.com with ESMTPSA id i30sm7305802wrc.8.2019.05.01.01.05.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 May 2019 01:05:57 -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> <737bfa62-eb3e-7c48-6356-0e0b76bb0593@FreeBSD.org> Message-ID: <76a05c08-b851-c50a-16fa-ac42c872413c@FreeBSD.org> Date: Wed, 1 May 2019 11:05:56 +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: <737bfa62-eb3e-7c48-6356-0e0b76bb0593@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 025D96A889 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of slavashwartsman@gmail.com designates 209.85.221.65 as permitted sender) smtp.mailfrom=slavashwartsman@gmail.com X-Spamd-Result: default: False [-4.07 / 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]; NEURAL_HAM_SHORT(-0.82)[-0.825,0]; 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]; FROM_NEQ_ENVFROM(0.00)[slavash@FreeBSD.org,slavashwartsman@gmail.com]; MID_RHS_MATCH_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]; TAGGED_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; 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)[65.221.85.209.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 08:06:07 -0000 On 01-May-19 10:28, Slava Shwartsman wrote: > > > 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 Got it now: panic: Assertion m->m_pkthdr.snd_tag == NULL failed at /usr/src/sys/netinet/ip_output.c:213 cpuid = 0 time = 1556697834 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00005ac1f0 vpanic() at vpanic+0x19d/frame 0xfffffe00005ac240 panic() at panic+0x43/frame 0xfffffe00005ac2a0 ip_output() at ip_output+0x159f/frame 0xfffffe00005ac3f0 ip_forward() at ip_forward+0x38c/frame 0xfffffe00005ac4b0 ip_input() at ip_input+0x7f5/frame 0xfffffe00005ac560 netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe00005ac5d0 ether_demux() at ether_demux+0x147/frame 0xfffffe00005ac600 ether_nh_input() at ether_nh_input+0x403/frame 0xfffffe00005ac660 netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe00005ac6d0 ether_input() at ether_input+0x7d/frame 0xfffffe00005ac700 vlan_input() at vlan_input+0x1e7/frame 0xfffffe00005ac750 ether_demux() at ether_demux+0x12d/frame 0xfffffe00005ac780 ether_nh_input() at ether_nh_input+0x403/frame 0xfffffe00005ac7e0 netisr_dispatch_src() at netisr_dispatch_src+0xa2/frame 0xfffffe00005ac850 ether_input() at ether_input+0x7d/frame 0xfffffe00005ac880 mlx5e_rx_cq_comp() at mlx5e_rx_cq_comp+0x8b4/frame 0xfffffe00005ac9a0 mlx5_cq_completion() at mlx5_cq_completion+0x5e/frame 0xfffffe00005ac9d0 mlx5_msix_handler() at mlx5_msix_handler+0x1ba/frame 0xfffffe00005aca10 ithread_loop() at ithread_loop+0x187/frame 0xfffffe00005aca70 fork_exit() at fork_exit+0x84/frame 0xfffffe00005acab0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00005acab0 --- trap 0, rip = 0, rsp = 0, rbp = 0 --- KDB: enter: panic [ thread pid 12 tid 100113 ] Stopped at kdb_enter+0x3b: movq $0,kdb_why I can keep the machine in this state for a while now if you want to take a look at anything specific. Slava