On Fri, 2004-10-15 at 03:18, matrix reloaded wrote: > I don't understand here what is wrong with my notion. What I said is > very clear, the > OS can't access user-level thread, right ? so schedular can't schedule > them ... I > may be missing something, but this point is not wrong... > > if you can jot down some basic points for a user-level thread, then > surely there is > only thing at the top, and that's noting but the fact that "OS doesn't > know about the > user-level threads and thas why it can't schedule them seperately on > multiple > processors on SMP"... > > Please tell me where exactly I am wrong... You are wrong with the assumption that NPTL is a user space implementation. The kernel does keep track of the userland threads. Check out http://people.redhat.com/drepper/nptl-design.pdf Specifically section 5.1 (1-on-1 vs. M-on-N): "It need not be mentioned that kernel threads are used; a pure user-level implementation could not take advantage of multi-processor machines which was one of the goals listed previously." -- Florin Malita <florin.malita@xxxxxxxxxxxx> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
