Messages in this thread | | | From | Con Kolivas <> | Subject | Re: isolcpus weirdness | Date | Thu, 23 Feb 2006 22:37:13 +1100 |
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On Thursday 23 February 2006 21:51, Emmanuel Pacaud wrote: > Le jeudi 23 février 2006 à 21:00 +1100, Con Kolivas a écrit : > > On Thursday 23 February 2006 20:55, Emmanuel Pacaud wrote: > > > Le mercredi 22 février 2006 à 22:18 +0100, Frederik Deweerdt a écrit : > > > > On Wed, Feb 22, 2006 at 02:21:27PM +0100, Emmanuel Pacaud wrote: > > > > > What's wrong ? > > > > > > > > Are you able to reproduce the same behaviour after disabling HT in > > > > the kernel config? > > > > > > I think HT is disabled in kernel config, since I only see 2 cpus. > > > > > > In fact, I've tried to enable HT, but did'nt succeed. HT is enabled in > > > BIOS, but I'm not sure about exact things I must set at kernel config > > > level for hyperthreading. I've tried to set/unset CONFIG_SCHED_SMT, but > > > that changes nothing (no hyperthreading, isolated cpu is always cpu0). > > > > > > Here's attached my config file. > > > > CONFIG_ACPI is not set > > > > You need ACPI to enumerate hyperthread siblings. That's why HT never gets > > enabled for you. > > Following your advice, I've set CONFIG_ACPI, and now, isolcpus works > fine, when hyperthreading is activated. > > But, I'm trying to build a real time system where hyperthreading is not > desired. So, I've tried to disable HT in BIOS, and the result is the > same as when ACPI is not enabled in kernel config: isolated cpu is > always cpu0. > > On the same machine, which is originally a Scientific Linux 4, I've > tried with distribution supplied kernel (a customized 2.6.9 with smp/HT > enabled): isolcpus works fine, even with HT disabled at BIOS level.
Sorry I was only explaining why hyperthreading wasn't working with your config. I don't know anything about your problem specifically.
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