Date: Sat, 22 Sep 2007 01:41:42 +0200 From: Kris Kennaway <kris@FreeBSD.org> To: Jack Vogel <jfvogel@gmail.com> Cc: Artem Kuchin <matrix@itlegion.ru>, freebsd-current@freebsd.org Subject: Re: TSP on em makes send of streams very slow Message-ID: <46F456B6.5060509@FreeBSD.org> In-Reply-To: <2a41acea0709211359w37ba779dsec94de504a9f4a9c@mail.gmail.com> References: <01c801c7fc7a$696ab900$0c00a8c0@Artem> <2a41acea0709211359w37ba779dsec94de504a9f4a9c@mail.gmail.com>
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Jack Vogel wrote: > On 9/21/07, Artem Kuchin <matrix@itlegion.ru> wrote: >> Hello! >> >> Here is what i have experienced today. >> >> I just installed 7.0-CURRENT (cvsed and build on 2007/09/20) >> on a PRODUCTION web server >> (because, IHMO, this current is stable enough and i like >> too much :) >> >> This is intel MB with two built-in em intefaces. >> >> I sshed to the server. >> While i was in plain shell everything was fine, but when i >> stared midnight commander i saw how it very slowly draws >> scren part by part. It took about 3 monutes to almost >> completely draw a screen when i got disconnected. I tied again >> - the same. Then i connected via ftp and uploaded 10MB file >> at 900KB/sec. When i tried to download it back i got about >> 500 *BYTES*/sec and the got disconnected in a couple of minutes. >> >> Ping was just find, even flood ping from the server on the save >> switch with 15000 packets was fine (just one dot on the left). >> >> I went also crazy already when i desided to compare interface params >> with another server with em NICs. >> >> The dfference is that this is has the following options (by DEFAULT, >> i did not turn it on): >> >> VLAN_HWCSUM,TSO4 >> >> I've read about TSO on 'man ifconfig' and just for kicks decided >> to turn it off. VOILA!!! In a seconds send speed was up to 10 MBYTES/sec! >> >> I have googled about 'em tso slow ' etc.. and found a couple of seemingly >> the same problem dated back 2006. Is it supposed to be solved by now? >> What IS the problem with TSO? > > TSO is for some environments, it isn't gonna be useful at 100Mb (which you > are), it can be useful at 1Gb but not always, when you get to 10G its > a HUGE benefit. > > Just cuz you can shoot yourself in the foot doesn't mean the gun has a > problem :) So the card can't handle it? Note that the OP says it was enabled automatically. I wouldn't necessarily expect it to give a performance benefit, but it shouldn't destroy performance to that extent either. There seems to be a real problem to be addressed here. Kris
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