Christoph Lameter wrote: > On Tue, 13 Oct 2009, Tejun Heo wrote: > >> Oh... one question tho. I used __this_cpu_*() as other conversions >> but I think we should be using the version without the underscores. >> The relationship between get_cpu_var() and __get_cpu_var() is >> different from the one between this_cpu_*() and __this_cpu_*(). > > For operations like inc/add/dec/sub you need to use the version with __ > otherwise the arches that do not support these operations will have to > generate useless expensive code that disables / reenables preempt. > > For this_cpu_ptr / __this_cpu_ptr it does not matter. this_cpu_ptr gives > you additional checks. Yes, you're right. The naming scheme in percpu sucks really hard. The subtle differences among [__]get_cpu_var(), [__]this_cpu_ptr() and other this_cpu ops. Arghhhhhh....... -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
