On Tue, Sep 04, 2012 at 05:46:19PM -0700, Josh Triplett wrote: > > It actually does depend on SMP. There has to be at least one CPU taking > > scheduling-clock interrupts in order to keep time computation accurate, > > so a de-facto UP system cannot adaptive-dynticks its sole CPU. > > Ah. That seems like a removable limitation, albeit a difficult one. > Nonetheless, it makes sense to avoid providing the option when it won't > help. > > However, once a config symbol for adaptive dynticks exists, perhaps that > symbol should depend on SMP and RCU_USER_QS should depend on that > instead, documenting the limitation in the right place and making it > easier to find and change eventually.
Right! And in fact CONFIG_RCU_USER_QS is a temporary config. Once we'll have CONFIG_NO_HZ_FULL, we won't need intermediate configs like this. And CONFIG_NO_HZ_FULL will depend on SMP anyway. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
