Messages in this thread | | | Subject | Re: Severe IRQ problems on Foster (P4 Xeon) system | Date | Wed, 13 Mar 2002 22:51:46 +0000 (GMT) | From | Alan Cox <> |
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> If several processors are idle, say CPU0 busy and CPU[123] idle, does it > preferentially use a "CPU" on another chip? And does that make any > difference? It's not clear to me if the HT CPUs share cache or not, they > obviously share bandwidth from L2 to RAM.
The scheduler changes try to schedule onto a new true CPU rather than a sibling first. Typically you only gain 10-30% via the HT feature so you want to load the "real" CPU's properly.
> I'm looking at P4 chips and boards, my 2Q02 budget has some $$ for a > system. I also will be getting some laptops 3Q02, does the new P4-M mobile > chip by any chance have HT? If so a good reason to go Intel, assuming that > either the BIOS or Linux can get it to use the feature ;-)
At the moment HT is Xeon only. Linux can do the right thing with it as of 2.4.18 + acpismp=force. Autodetect should be in soon. I don't know about Intel's future product plans for HT.
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