Date: Fri, 16 Jan 2004 10:00:30 -0000 From: "Hall J D (ISeLS)" <jdhall@glam.ac.uk> To: 'John Baldwin' <jhb@FreeBSD.org>, "'freebsd-smp@freebsd.org'" <freebsd-smp@freebsd.org> Subject: RE: machdep.hlt_logical_cpus missing in 4.9-Release? Message-ID: <EF1C49A3F569D41186C900508B6DDC991359356B@ems3.glam.ac.uk>
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> -----Original Message----- > From: John Baldwin > Sent: 15 January 2004 18:06 > > On Thursday 15 January 2004 05:48 am, Hall J D (ISeLS) wrote: > > I've recently installed 4.9-Release (from the ISOs) on a > twin Xeon system > > and compiled a generic SMP kernel (GENERIC with SMP and > APIC_IO enabled). > > > > The problem I'm having is the system is using the logical > HyperThreading > > CPUs even though I don't want it to. > > > > The errata for 4.9-Release says that the logical CPUs are > prevented from > > executing user processes by default, they are not on my > system. It also > > says you can control this behaviour by change the value of the > > machdep.hlt_logical_cpus sysctl(8) variable. My sysctl > doesn't seem to know > > about this variable. > > > > Well, you can do 'sysctl machdep.hlt_cpus=10 to get the same > effect to turn > off CPU's 1and 3. I am not sure why you are not getting the > sysctls. Are > you familiar with C? I am not familiar with C, but I'm happy to check what I can if you point me in the right direction. The machine I was using for these tests has now gone into production so I'll have to build another before I can test the machdep.hlt_cpus option. I'll do that in the next few days and let you know how it goes. Thanks, Jonathan
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