Date: Sat, 17 Feb 2007 12:02:10 +0200 From: Cheffo <cheffo@FreeBSD-BG.org> To: garcol@postino.it Cc: freebsd-performance@freebsd.org Subject: Re: bizarre performance issues in 6.2 release Message-ID: <45D6D2A2.8090000@FreeBSD-BG.org> In-Reply-To: <002801c75271$0afa5af0$1df522d4@elitel> References: <002801c75271$0afa5af0$1df522d4@elitel>
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Hi all, garcol@postino.it wrote: > See kern/83406: [smp] em/bge drivers: severe performance loss under SMP > > > sysctl machdep.cpu_idle_hlt=0 > (sysctl machdep.hyperthreading_allowed=1) What actually do this ? (sysctl machdep.cpu_idle_hlt=0) From this PR (kern/83406) it seems that if you want full performance you need machdep.cpu_idle_hlt=0 and machdep.hyperthreading_allowed=0 or machdep.cpu_idle_hlt=1 and machdep.hyperthreading_allowed=1, and others combination drop performance .. Am I getting it right ? And if yes why by default HT is disable, but machdep.cpu_idle_hlt is enabled ? I'm little confused :) > > Regards > Alessandro > >> Try disabling hyperthreading on the 6.2-server. In some cases you get >> a moderate performance-increase, in most cases this setting is >> counter-productive. >> >> regards >> Claus > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" > > -- Best Wishes, Stefan Lambrev ICQ# 24134177help
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