sparc64: Only allocate per-cpu areas for possible cpus. (0c243ad8) · Commits · 戴 / test

This gets us real close to the generic implementation of setup_per_cpu_areas() except: 1) We store the per-cpu offset into the trap_block[], whereas the generic code has it's own static array. 2) We have to initialize the %g5 register to hold the boot cpu's per-cpu area offset. 3) The OBP/MDESC cpu info scan is performed at the end. Signed-off-by:

David S. Miller <davem@davemloft.net>

arch/sparc/kernel/smp_64.c

+6 −16

Original line number	Diff line number	Diff line
		@@ -1373,27 +1373,17 @@ void smp_send_stop(void)

		void __init setup_per_cpu_areas(void)
		{
		unsigned long base, shift, goal, size, i;
		unsigned long size, i, nr_possible_cpus = num_possible_cpus();
		char *ptr;

		/* Copy section for each CPU (we discard the original) */
		goal = PERCPU_ENOUGH_ROOM;
		size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
		ptr = alloc_bootmem_pages(size * nr_possible_cpus);

		shift = PAGE_SHIFT;
		for (size = PAGE_SIZE; size < goal; size <<= 1UL)
		shift++;

		ptr = __alloc_bootmem(size * NR_CPUS, PAGE_SIZE, 0);
		if (!ptr) {
		prom_printf("Cannot allocate per-cpu memory.\n");
		prom_halt();
		}

		base = ptr - __per_cpu_start;

		for (i = 0; i < NR_CPUS; i++, ptr += size) {
		__per_cpu_offset(i) = base + (i * size);
		for_each_possible_cpu(i) {
		__per_cpu_offset(i) = ptr - __per_cpu_start;
		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
		ptr += size;
		}

		/* Setup %g5 for the boot cpu. */

Admin message