On Mon, 8 Aug 2005, Alexander Nyberg wrote: > > IRQ_PER_CPU is not used by all architectures. > > This patch introduces the macros > > ARCH_HAS_IRQ_PER_CPU and CHECK_IRQ_PER_CPU() to avoid the generation of > > dead code in __do_IRQ(). > > > > ARCH_HAS_IRQ_PER_CPU is defined by architectures using > > IRQ_PER_CPU in their > > include/asm_ARCH/irq.h > > file. > > > > Through grepping the tree I found the following > > architectures currently use IRQ_PER_CPU: > > > > cris, ia64, ppc, ppc64 and parisc. > > > > There are many places where one could replace run-time tests with > #ifdef's but it makes reading more difficult (and in longer terms > maintainence). Have you benchmarked any workload that benefits > from this?
I doubt you'd be able to collect convincing benchmark data, but skipping a branch (possibly mispredicted) is worth it IMO. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
