Messages in this thread | | | From | Denis Vlasenko <> | Subject | Re: Hardware limits on numbers of threads? | Date | Wed, 18 Sep 2002 09:37:58 -0200 |
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On 18 September 2002 04:43, Dan Kegel wrote: > http://people.redhat.com/drepper/glibcthreads.html says: > > Hardware restrictions put hard limits on the number of > > threads the kernel can support for each process. > > Specifically this applies to IA-32 (and AMD x86_64) where the thread > > register is a segment register. The processor architecture > > puts an upper limit on the number of segment register values > > which can be used (8192 in this case). > > Is this true? Where does the limit come from?
It is true that on x86 you have only 8192 different segment selectors at a time. Nobody says you can't modify segment descriptors on demand.
If I'm not mistaken, Linux kernel does precisely this. It has per-CPU allocated GDT entries, not per-task. So there is no limitation unless you happen to have more than 1024 CPUs ;-). -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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