Date: Mon, 2 Jul 2001 14:24:17 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: Alfred Perlstein <bright@sneakerz.org> Cc: "Michael C . Wu" <keichii@peorth.iteration.net>, "E.B. Dreger" <eddy+public+spam@noc.everquick.net>, smp@FreeBSD.ORG Subject: Re: per cpu runqueues, cpu affinity and cpu binding. Message-ID: <Pine.BSF.4.21.0107021420570.13213-100000@InterJet.elischer.org> In-Reply-To: <20010702141113.Q84523@sneakerz.org>
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On Mon, 2 Jul 2001, Alfred Perlstein wrote: > * Julian Elischer <julian@elischer.org> [010702 13:38] wrote: > > > > At USENIX we decided to proceed with the KSE work. > > yay! > > > > > As a side issue I plan on NOT ALLOWING multiple KSEs (thread carriers?) > > from the same thread group in the same process to be on the same > > processor. SO load balancing and processor affinity will not > > apply to the thread-carrying entities (KSEs). Of course the userland > > thread scheduler has the ultimate say as to which processor > > a thread is scheduled on. > > Actually, this may cause some performance problems, when you have > a shared address space you can avoid tlb shootdowns when a process's > address space changes, you also share the cache, lastly there's > some rumor about a new CPU archetecture that runs multple threads > on the same CPU at the same time. Just food for thought. If you select to run 2 thread carriers (see other mail on nomenclature)> (KSEs) then you have specifically asked for 2 processors worth of concurrency so we ASSUME you know what you are doing.. If you want to run all the threads on a single processor to get better cache activity, then you should't ASK to run on 2 (or more) processors. :-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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