Date: Thu, 07 Feb 2008 11:43:18 +0200 From: Stefan Lambrev <stefan.lambrev@moneybookers.com> To: Kris Kennaway <kris@FreeBSD.org> Cc: "freebsd-performance@freebsd.org" <freebsd-performance@freebsd.org> Subject: Re: network performance Message-ID: <47AAD2B6.6070106@moneybookers.com> In-Reply-To: <47AA3DF9.5040109@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> <47A8DCD6.3060209@moneybookers.com> <47A8E1F1.4040309@FreeBSD.org> <47A98CDC.2090407@moneybookers.com> <47A993D0.1060901@FreeBSD.org> <47A99736.8060809@moneybookers.com> <47A99B16.6030305@FreeBSD.org> <47A9B636.3040509@moneybookers.com> <47A9C43A.3030203@moneybookers.com> <47AA1858.3050307@FreeBSD.org> <47AA37CA.8020208@moneybookers.com> <47AA3DF9.5040109@FreeBSD.org>
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Greetings, Kris Kennaway wrote: > Stefan Lambrev wrote: >> Greetings, >> >> Kris Kennaway wrote: >>> Stefan Lambrev wrote: >>> >>>>> I'll use again hwpmc and LOCK_PROFILING to see what's going on. >>>>> And will try the same benchmark on quad core processor as now >>>>> numbers of cores/cpus matter :) >>>>> >>>> Here are promised results - http://89.186.204.158/lock_profiling-8.txt >> Finally I got pmcstat working - http://89.186.204.158/hwpmc-p4.txt >> The stats are gathered during 600kpp incoming. >> I think that syncache or what calls MD5Transform is not SMP able, and >> that's why outgoing 250kpps is the limit that I can't beat. > > It looks like the syncache is using most of the CPU time. However you > are not hitting problems caused by lack of concurrency there. It does > do a *lot* of work with the syncache mutex held (including generation > of the cookie, which involves MD5) so it might be an issue in the > future, but there are other bottlenecks in the way before that is your > main issue. Things may be different with more CPUs. > > Did you compare to what happens to performance when the syncache is > disabled? > > Kris > When I disable syncookies the server respond to more packets - from 250kpps enabled to 320kpps when disabled. Can I disable syncache and how? I'll try to increase syncache limits and will test again. Btw is this expected - net.inet.tcp.syncache.count: -387. I think this number should be always > 0. -- Best Wishes, Stefan Lambrev ICQ# 24134177
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