Steffen Klassert said, at 2012/11/13 15:21: > > This should just fetch the tfm pointer, so why exactly __this_cpu_read > is better than __this_cpu_ptr? Please keep in mind that performance is > not the most important thing here. It's much more important that it > works in any case. [0/9] describes why we should submit this series patches. you are not included in original mail.
this_cpu_ptr relocates and address. this_cpu_read() relocates the address and performs the fetch. If you want to operate on rda(defined as per_cpu) then you can only use this_cpu_ptr. this_cpu_read() saves you more instructions since it can do the relocation and the fetch in one instruction. More info, please refer to http://www.spinics.net/lists/kernel/msg1435153.html -- 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/
