Date: Wed, 30 Aug 2006 10:46:54 -0700 From: Skylar Thompson <skylar@cs.earlham.edu> To: Jordi Carrillo <jordilin@gmail.com> Cc: freebsd-questions@freebsd.org Subject: Re: SMP detection Message-ID: <44F5CF0E.9020700@cs.earlham.edu> In-Reply-To: <94ff3700608301020l34251166nbdb4d72842e1bb86@mail.gmail.com> References: <94ff3700608301020l34251166nbdb4d72842e1bb86@mail.gmail.com>
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[-- Attachment #1 --] Jordi Carrillo wrote: > I've read that SMP should be disabled for performance issues (I did > not know > that before installing freebsd). I have a P4 3GHz with hyperthreading > technology. I have the SMP-GENERIC kernel and it only launches one > cpu. So, > I've decided to disable SMP from BIOS. Is that ok?, knowing that I have a > Smp enabled kernel? or should I install one without smp? If so, is > there a > way to install one already precompiled? > Thanks in advance > I believe that HTT was disabled in FreeBSD per security report FreeBSD-SA-05:09.htt (http://security.freebsd.org/advisories/FreeBSD-SA-05:09.htt.asc). If you want to enable, I believe you can set the loader.conf option machdep.hlt_logical_cpus to 2. Having SMP enabled on a uniprocessor box shouldn't give you any stability problems, but SMP does use a different locking mechanism that can affect performance. You will probably get slightly better performance if you run with an SMP-disabled kernel. -- -- Skylar Thompson (skylar@cs.earlham.edu) -- http://www.cs.earlham.edu/~skylar/ [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (SunOS) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFE9c8Qsc4yyULgN4YRAjmuAJ97hk0s6o3hvZwW0w7mnlhXd61slwCggxE/ QTa2GUOmwlPdHMXsJ4W+dmg= =PBGK -----END PGP SIGNATURE-----help
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