Date: Thu, 28 Apr 2011 08:39:57 -0400 From: Adam Stylinski <kungfujesus06@gmail.com> To: freebsd-net@freebsd.org Subject: Re: em0 performance subpar Message-ID: <BANLkTim1OdpK83YtkeoXKP_j=K99A-BD6A@mail.gmail.com> In-Reply-To: <20110428123847.GA85701@freebsdbox.adamsnet> References: <20110428072946.GA11391@zephyr.adamsnet> <4DB946CE.4030901@rdtc.ru> <20110428123847.GA85701@freebsdbox.adamsnet>
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--00151747b8d8d6bba204a1f9da06 Content-Type: text/plain; charset=ISO-8859-1 ---------- Forwarded message ---------- From: Adam Stylinski <kungfujesus06@gmail.com> Date: Thu, Apr 28, 2011 at 8:38 AM Subject: Re: em0 performance subpar To: Eugene Grosbein <egrosbein@rdtc.ru> On Thu, Apr 28, 2011 at 05:51:58PM +0700, Eugene Grosbein wrote: > On 28.04.2011 14:29, Adam Stylinski wrote: > > Hello, > > > > I have an intel gigabit network adapter (the 1000 GT w/chipset 82541PI) which performs poorly in Freebsd compared to the same card in Linux. I've tried this card in two different freebsd boxes and for whatever reason I get poor transmit performance. I've done all of the tweaking specified in just about every guide out there (the usual TCP window scaling, larger nmbclusters, delayed acks, etc) and still I get only around 600mbps. I'm using jumbo frames, with an MTU of 9000. I'm testing this with iperf. While I realize that this may not be the most realistic test, linux hosts with the same card can achieve 995Mbit/s to another host running this. When the Freebsd box is the server, Linux hosts can transmit to it at around 800 something Mbit/s. I've increased the transmit descriptors as specified in the if_em man page, and while that gave me 20 or 30 more mbit/s, my transmit performance is still below normal. > > > > sysctl stats report that the card is trigger a lot of tx_desc_fail2: > > dev.em.0.tx_desc_fail2: 3431 > > > > Looking at a comment in the source code this indicates that the card was not able to obtain enough transmit descriptors (but I've given the card the maximum of 4096 in my loader.conf tunable). Is this a bug or a performance regression of some kind? Does anybody have a fix for this? I tried another card with the same chip in a different box on 8-STABLE to no avail (the box I'm trying to improve performance on is on 8.2-RELEASE-p1). > > > > Anybody manage to make this card push above 600mbps in ideal network benchmarks? Any help would be gladly appreciated. > > Please show output of "vmstat -z|egrep 'ITEM|mbuf'" command after the test. > > Eugene Grosbein ITEM SIZE LIMIT USED FREE REQUESTS FAILURES mbuf_packet: 256, 0, 4096, 896, 531481, 0 mbuf: 256, 0, 1026, 10497, 3882824, 0 mbuf_cluster: 2048, 65768, 4992, 2998, 105908, 0 mbuf_jumbo_page: 4096, 12800, 0, 4462, 1261679, 0 mbuf_jumbo_9k: 9216, 6400, 0, 0, 0, 0 mbuf_jumbo_16k: 16384, 3200, 0, 0, 0, 0 mbuf_ext_refcnt: 4, 0, 0, 168, 1, 0 I'm willing to try compiling the module with EM_MULTIQUEUE on the test box to see if it makes a difference, but I read it can have issues with UDP traffic. -- Adam Stylinski PGP Key: http://pohl.ececs.uc.edu/~adam/publickey.pub Blog: http://technicallyliving.blogspot.com --00151747b8d8d6bba204a1f9da06 Content-Type: application/pgp-signature Content-Disposition: attachment Content-Transfer-Encoding: base64 X-Attachment-Id: d83242f6e3f9e33_0.1 LS0tLS1CRUdJTiBQR1AgU0lHTkFUVVJFLS0tLS0KVmVyc2lvbjogR251UEcgdjIuMC4xNyAoRnJl ZUJTRCkKCmlRSWNCQUVCQWdBR0JRSk51Vi9QQUFvSkVENnNSSEU2VHZtbmRZOFFBSzVvNWFXdlY1 VVJlWkluU1dRTWR6MmEKWmpOb2d3R3I2eEVCV3Z3dmZmYllhWHljSkgxTnhDU0dYWGFVRVpIbFRs RFk0R240dEs2eWhkaDhpa0VuN28wYwpjRGsrSy9ONUhXMlFqQnVvNTIxY2pPOG52MElSWnpmNk82 ZnRyamQvM0FtVFViSXhTdU9LNHFHdXZycE55UXpTCm5rQVVmUmJnaDMxcElINEpMN0JqaTNZczBH ZHdWUm1PSEl5b3k4cWVDQTlyQ3p2WDRSYS9CVDFycG5oWjgwdHMKMnpjWXdQc3lYd0JrZy9qUDZM VGh5bSt6Qlp1QTBPcW1EN1RERnRWYTlaYzRMcENVb2xoZDZjN3dXTTdxZjBoVQplOU1ULzNFVHkr UXBUaDVkRCtaOU9HcmdqbGxlWXZKUm1CVWNPQmtuVW51ZHF4SVJqQlM4N1FzSmN4eFhpOHAvCk94 b21MTFVoR244eTNCUnV0R2lhdXdncmpyOEd3bWxHN0JYV1NXV0hsQUducVdnSkxKQWJ4SkNPN3Rj d2ZkcXgKcGd3VWx6eW1wYVFKcFI2UHpuMTlXVDBZOENFektPMCtUSHg0NzBxbVV1RHpnbkJUNFRQ bWVDSnQxVkdBLzkyWQplZnYzMGFYM2VUcXlDdDE0RU1OaGx0S0VyajVQVW1raGdUYWVWOGRwNlR6 Q0phYmUvWWRPU3V6M3pnS0lIckE5ClNFUWtIYVZiOEJaSFUvWHFTYWhFUVB1c3gxYzVsMnhZcVND WGQrUytsWk91Lzl1cDdBSnlmYTBJc2ZGTTlkaTgKb2VPcDRYN2tRM0pOU0N5OVJLeVVsdHM2allo c0cvTlJYV3kwRnI4SnFwTGRDR2MvVWRndGxBMFExanVNeGR2SgprUURubnJXcnVRbHdLd3VVN1M0 SQo9NWV1WAotLS0tLUVORCBQR1AgU0lHTkFUVVJFLS0tLS0K --00151747b8d8d6bba204a1f9da06--
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