From owner-svn-src-head@freebsd.org Mon Apr 29 21:14:23 2019 Return-Path: Delivered-To: svn-src-head@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 4802B159E443; Mon, 29 Apr 2019 21:14:23 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E2C5275978; Mon, 29 Apr 2019 21:14:22 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from John-Baldwins-MacBook-Pro-3.local (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id E82B411244; Mon, 29 Apr 2019 21:14:21 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Subject: Re: svn commit: r341586 - head/sys/dev/mlx5/mlx5_en To: slavash@FreeBSD.org, 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> From: John Baldwin Openpgp: preference=signencrypt Autocrypt: addr=jhb@FreeBSD.org; keydata= mQGiBETQ+XcRBADMFybiq69u+fJRy/0wzqTNS8jFfWaBTs5/OfcV7wWezVmf9sgwn8TW0Dk0 c9MBl0pz+H01dA2ZSGZ5fXlmFIsee1WEzqeJzpiwd/pejPgSzXB9ijbLHZ2/E0jhGBcVy5Yo /Tw5+U/+laeYKu2xb0XPvM0zMNls1ah5OnP9a6Ql6wCgupaoMySb7DXm2LHD1Z9jTsHcAQMD /1jzh2BoHriy/Q2s4KzzjVp/mQO5DSm2z14BvbQRcXU48oAosHA1u3Wrov6LfPY+0U1tG47X 1BGfnQH+rNAaH0livoSBQ0IPI/8WfIW7ub4qV6HYwWKVqkDkqwcpmGNDbz3gfaDht6nsie5Z pcuCcul4M9CW7Md6zzyvktjnbz61BADGDCopfZC4of0Z3Ka0u8Wik6UJOuqShBt1WcFS8ya1 oB4rc4tXfSHyMF63aPUBMxHR5DXeH+EO2edoSwViDMqWk1jTnYza51rbGY+pebLQOVOxAY7k do5Ordl3wklBPMVEPWoZ61SdbcjhHVwaC5zfiskcxj5wwXd2E9qYlBqRg7QeSm9obiBCYWxk d2luIDxqaGJARnJlZUJTRC5vcmc+iGAEExECACAFAkTQ+awCGwMGCwkIBwMCBBUCCAMEFgID AQIeAQIXgAAKCRBy3lIGd+N/BI6RAJ9S97fvbME+3hxzE3JUyUZ6vTewDACdE1stFuSfqMvM jomvZdYxIYyTUpC5Ag0ERND5ghAIAPwsO0B7BL+bz8sLlLoQktGxXwXQfS5cInvL17Dsgnr3 1AKa94j9EnXQyPEj7u0d+LmEe6CGEGDh1OcGFTMVrof2ZzkSy4+FkZwMKJpTiqeaShMh+Goj XlwIMDxyADYvBIg3eN5YdFKaPQpfgSqhT+7El7w+wSZZD8pPQuLAnie5iz9C8iKy4/cMSOrH YUK/tO+Nhw8Jjlw94Ik0T80iEhI2t+XBVjwdfjbq3HrJ0ehqdBwukyeJRYKmbn298KOFQVHO EVbHA4rF/37jzaMadK43FgJ0SAhPPF5l4l89z5oPu0b/+5e2inA3b8J3iGZxywjM+Csq1tqz hltEc7Q+E08AAwUIAL+15XH8bPbjNJdVyg2CMl10JNW2wWg2Q6qdljeaRqeR6zFus7EZTwtX sNzs5bP8y51PSUDJbeiy2RNCNKWFMndM22TZnk3GNG45nQd4OwYK0RZVrikalmJY5Q6m7Z16 4yrZgIXFdKj2t8F+x613/SJW1lIr9/bDp4U9tw0V1g3l2dFtD3p3ZrQ3hpoDtoK70ioIAjjH aIXIAcm3FGZFXy503DOA0KaTWwvOVdYCFLm3zWuSOmrX/GsEc7ovasOWwjPn878qVjbUKWwx Q4QkF4OhUV9zPtf9tDSAZ3x7QSwoKbCoRCZ/xbyTUPyQ1VvNy/mYrBcYlzHodsaqUDjHuW+I SQQYEQIACQUCRND5ggIbDAAKCRBy3lIGd+N/BCO8AJ9j1dWVQWxw/YdTbEyrRKOY8YZNwwCf afMAg8QvmOWnHx3wl8WslCaXaE8= Message-ID: <67b638e0-8e6f-f960-b263-62eed8ce28b7@FreeBSD.org> Date: Mon, 29 Apr 2019 14:14:19 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <123654bf-59f7-1db8-55ce-36306bdac43d@FreeBSD.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E2C5275978 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.92 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.92)[-0.918,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Apr 2019 21:14:23 -0000 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. -- John Baldwin