Yinghai Lu <[EMAIL PROTECTED]> writes: > we don't need copy too. already have x86_cpu_to_node_map
That's a regression (probably from Mike's patches?). Until recently it was used. The reason the node number was put in there is that it generates far shorter code to just fetch the local node number from the PDA than to first go through a array lookup from the cpu number. It also saves a costly cache line miss on the array if you're unlucky. It is far better to fix it than to remove it. I know Mike/Christoph want to get rid of the PDA and make per cpu data as efficient as the PDA. If that happens the right fix is to create a new per CPU data variable for the node number again. Here's a quick patch (tested on kvm with numa emulation only) It should be ok because PDA is set up early and the early node is always 0 and there is a 0 in there at early boot. Saves about 1.6k of text on a vmlinux here. Signed-off-by: Andi Kleen <[EMAIL PROTECTED]> Index: linux/include/asm-x86/topology.h =================================================================== --- linux.orig/include/asm-x86/topology.h +++ linux/include/asm-x86/topology.h @@ -34,11 +34,12 @@ extern int cpu_to_node_map[]; #else +#include <asm/pda.h> DECLARE_PER_CPU(int, x86_cpu_to_node_map); extern int x86_cpu_to_node_map_init[]; extern void *x86_cpu_to_node_map_early_ptr; /* Returns the number of the current Node. */ -#define numa_node_id() (early_cpu_to_node(raw_smp_processor_id())) +#define numa_node_id() (read_pda(nodenumber)) #endif extern cpumask_t node_to_cpumask_map[]; -- 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/
