On 6/27/05, Jan Hudec <bulb@xxxxxx> wrote: > On Mon, Jun 27, 2005 at 10:59:39 +0900, NAHieu wrote: > > On 6/27/05, Tetsuo Handa <from-kernelnewbies@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > I am writing a kernel module, and I want to get the number of CPU. If > > > > > the machine is UP, the value returned will be 1, but if the machine is > > > > > SMP, the value returned will be the number of CPU available. > > > > > > > > I think NR_CPUS give the number of the cpu in the system. You can use it > > > > > > NR_CPUS is the max number that kernel supports. > > > I think num_online_cpus() is what you want. > > > http://lxr.linux.no/source/include/linux/cpumask.h#L349 > > > > Looks like num_online_cpus() is not exported, so it is impossible to > > use it from a module, isnt it? > > Did you even bother to look at the link above ?!?! > > If you did, you'd know that it is a preprocessor macro, so it does not > have a symbol that'd need exporting. Also you'd learn that it actually > uses a function underneath, which is exported. Jan, i see that. Another question: if I want to get the number of CPU from userspace, it is possible to find it in /proc/cpu. Is there any other way (using library, syscall,...) to do that? Thank you, Hieu -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
