On Tue, 06 Feb 2007 16:53:27 +0100, Franck Bui-Huu <vagabon.xyz@xxxxxxxxx> wrote: > This patch makes these routines a lot more readable whatever > the value of CONFIG_PREEMPT. > > It also moves one branch instruction from ret_from_irq() > to ret_from_exception(). Therefore we favour the return > from irq path which should be more common than the other > one. After this patch, entry.S becomes: FEXPORT(ret_from_exception) #ifndef CONFIG_PREEMPT local_irq_disable # preempt stop #endif b _ret_from_irq FEXPORT(ret_from_irq) LONG_S s0, TI_REGS($28) FEXPORT(_ret_from_irq) Apparently your patch add an additional branch in critical path in CONFIG_PREEMPT=y case. Maybe this would be better? #ifdef CONFIG_PREEMPT FEXPORT(ret_from_irq) LONG_S s0, TI_REGS($28) FEXPORT(ret_from_exception) #else FEXPORT(ret_from_exception) local_irq_disable # preempt stop b _ret_from_irq FEXPORT(ret_from_irq) LONG_S s0, TI_REGS($28) #endif FEXPORT(_ret_from_irq) --- Atsushi Nemoto
