Date: Wed, 06 Feb 2008 00:01:58 +0200 From: Stefan Lambrev <stefan.lambrev@moneybookers.com> To: Kris Kennaway <kris@FreeBSD.org> Cc: freebsd-performance@freebsd.org, Andrew Thompson <thompsa@FreeBSD.org> Subject: Re: network performance Message-ID: <47A8DCD6.3060209@moneybookers.com> In-Reply-To: <47A8D233.8020506@FreeBSD.org> References: <4794E6CC.1050107@moneybookers.com> <47A0B023.5020401@moneybookers.com> <m21w7x5ilg.wl%gnn@neville-neil.com> <47A3074A.3040409@moneybookers.com> <47A72EAB.6070602@moneybookers.com> <20080204182945.GA49276@heff.fud.org.nz> <47A780C0.2060201@moneybookers.com> <47A799A6.3070502@moneybookers.com> <47A84751.8020109@moneybookers.com> <47A8D233.8020506@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Hello, Kris Kennaway wrote: > Stefan Lambrev wrote: > >>>>> Thanks for investigating this. One thing to note is that ip flows >>>>> from >>>>> the same connection always go down the same interface, this is >>>>> because >>>>> Ethernet is not allowed to reorder frames. The hash uses >>>>> src-mac, dst-mac, src-ip and dst-ip (see lagg_hashmbuf), make sure >>>>> when >>>>> performance testing that your traffic varies in these values. Adding >>>>> tcp/udp ports to the hashing may help. >>>>> >>>> The traffic, that I generate is with random/spoofed src part, so it >>>> is split between interfaces for sure :) >>>> >>>> Here you can find results when under load from hwpmc and >>>> lock_profiling: >>>> http://89.186.204.158/lock_profiling-lagg.txt > > OK, this shows the following major problems: > > 39 22375065 1500649 5690741 3 0 119007 > 712359 /usr/src/sys/net/route.c:147 (sleep mutex:radix node head) > 21 3012732 1905704 1896914 1 1 14102 > 496427 /usr/src/sys/netinet/ip_output.c:594 (sleep mutex:rtentry) > 22 120 2073128 47 2 44109 0 > 3 > /usr/src/sys/modules/if_lagg/../../net/ieee8023ad_lacp.c:503 > (rw:if_lagg rwlock) > 39 17857439 4262576 5690740 3 0 95072 > 1484738 /usr/src/sys/net/route.c:197 (sleep mutex:rtentry) > > It looks like the if_lagg one has been fixed already in 8.0, it could > probably be backported but requires some other infrastructure that > might not be in 7.0. > > The others are to do with concurrent transmission of packets (it is > doing silly things with route lookups). kmacy has a WIP that fixes > this. If you are interested in testing an 8.0 kernel with the fixes > let me know. Well those servers are only for tests so I can test everything, but at some point I'll have to make final decision what to use in production :) > >>>> http://89.186.204.158/lagg-gprof.txt >>>> >>> http://89.186.204.158/lagg2-gprof.txt I forget this file :) >>> >> I found that MD5Transform aways uses ~14% (with rx/txcsum enabled or >> disabled). > > Yeah, these don't have anything to do with MD5. Well I didn't find from where MD5Transform() is called, so I guess it's a some 'magic', that I still do not understand ;) > >> And when using without lagg MD5Transform pick up to 20% of the time. >> Is this normal? > > It is probably from the syncache. You could disable it > (net.inet.tcp.syncookies_only) if you don't need strong protection > against SYN flooding. > > Kris How the server perform during SYN flooding is exactly what I test at the moment :) So I can't disable this. Just for information, if someone is interested - I looked how linux (2.6.22-14-generic ubuntu) perform in the same situation .. by default it doesn't perform at all - it hardly replays to 100-200 packets/s, with syncookies enabled it can handle up to 70-90,000 pps (250-270,000 compared to freebsd), but the server is very loaded and not very responsible. Of course this doesn't mean that FreeBSD can't perform better ;) I plan to test iptables, newer kernel, various options, and may be few others distros.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?47A8DCD6.3060209>