Messages in this thread |  | | Date | Wed, 18 Sep 2002 03:05:23 -0400 | From | Jakub Jelinek <> | Subject | Re: Hardware limits on numbers of threads? |
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On Wed, Sep 18, 2002 at 09:37:58AM -0200, Denis Vlasenko wrote: > 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.
That page has been written way before set_thread_area(2) (and other kernel threading changes) were written.
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