On 02/11/2013 01:26 AM, Paul E. McKenney wrote: > On Mon, Feb 11, 2013 at 01:11:29AM +0530, Srivatsa S. Bhat wrote: >> On 02/09/2013 05:37 AM, Paul E. McKenney wrote: >>> On Tue, Jan 22, 2013 at 01:05:10PM +0530, Srivatsa S. Bhat wrote: >>>> Once stop_machine() is gone from the CPU offline path, we won't be able to >>>> depend on preempt_disable() to prevent CPUs from going offline from under >>>> us. >>>> >>>> Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going >>>> offline, >>>> while invoking from atomic context. >>>> >>>> Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com> >>> >>> Would it make sense for get_online_cpus_atomic() to return the current >>> CPU number? >> >> Hmm, I'm not so sure. I tried to model it after get_online_cpus(), which >> doesn't >> return anything (for other reasons, of course..) >> >> Moreover, a function name like *_cpu_* returning the CPU number would be >> intuitive. >> But a name such as *_cpus_* (plural) returning a CPU number might appear >> confusing.. >> >> And also I don't think it'll make a huge improvement in the callers.. (We >> might >> be better off avoiding an smp_processor_id() if possible, since this >> function could >> be called in very hot paths).. So I don't see a strong case for returning the >> CPU number. But let me know if you think it'll still be worth it for some >> reason... > > I just noted a lot of two-line code sequences in your patch that would be > one line if the CPU number was returned.
Ah, in that case, I'll reconsider your suggestion while working on the next version. Thanks! Regards, Srivatsa S. Bhat > But I don't feel strongly about > it, so if people are OK with the current version, no problem. > > Thanx, Paul > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
