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Commit bcb2107f authored by Tejun Heo's avatar Tejun Heo
Browse files

sparc64: use embedding percpu first chunk allocator 



sparc64 currently allocates a large page for each cpu and partially
remap them into vmalloc area much like what lpage first chunk
allocator did.  As a 4M page is used for each cpu, this results in
very large unit size and also adds TLB pressure due to the double
mapping of pages in the first chunk.

This patch converts sparc64 to use the embedding percpu first chunk
allocator which now knows how to handle NUMA configurations.  This
simplifies the code a lot, doesn't incur any extra TLB pressure and
results in better utilization of address space.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e933a73f

arch/sparc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -95,6 +95,9 @@ config AUDIT_ARCH 
config HAVE_SETUP_PER_CPU_AREA

	def_bool y if SPARC64



config NEED_PER_CPU_EMBED_FIRST_CHUNK

	def_bool y if SPARC64



config GENERIC_HARDIRQS_NO__DO_IRQ

	bool

	def_bool y if SPARC64

arch/sparc/kernel/smp_64.c

+18 −110
Original line number Diff line number Diff line
@@ -1389,8 +1389,8 @@ void smp_send_stop(void) 
 * RETURNS:

 * Pointer to the allocated area on success, NULL on failure.

 */

static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,

					unsigned long align)

static void * __init pcpu_alloc_bootmem(unsigned int cpu, size_t size,

					size_t align)

{

	const unsigned long goal = __pa(MAX_DMA_ADDRESS);

#ifdef CONFIG_NEED_MULTIPLE_NODES
@@ -1415,123 +1415,31 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, 
#endif

}



#define PCPU_CHUNK_SIZE (4UL * 1024UL * 1024UL)



static void __init pcpu_map_range(unsigned long start, unsigned long end,

				  struct page *page)

static void __init pcpu_free_bootmem(void *ptr, size_t size)

{

	unsigned long pfn = page_to_pfn(page);

	unsigned long pte_base;



	BUG_ON((pfn<<PAGE_SHIFT)&(PCPU_CHUNK_SIZE - 1UL));



	pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4U |

		    _PAGE_CP_4U | _PAGE_CV_4U |

		    _PAGE_P_4U | _PAGE_W_4U);

	if (tlb_type == hypervisor)

		pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4V |

			    _PAGE_CP_4V | _PAGE_CV_4V |

			    _PAGE_P_4V | _PAGE_W_4V);



	while (start < end) {

		pgd_t *pgd = pgd_offset_k(start);

		unsigned long this_end;

		pud_t *pud;

		pmd_t *pmd;

		pte_t *pte;



		pud = pud_offset(pgd, start);

		if (pud_none(*pud)) {

			pmd_t *new;



			new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);

			pud_populate(&init_mm, pud, new);

	free_bootmem(__pa(ptr), size);

}



		pmd = pmd_offset(pud, start);

		if (!pmd_present(*pmd)) {

			pte_t *new;



			new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);

			pmd_populate_kernel(&init_mm, pmd, new);

		}



		pte = pte_offset_kernel(pmd, start);

		this_end = (start + PMD_SIZE) & PMD_MASK;

		if (this_end > end)

			this_end = end;



		while (start < this_end) {

			unsigned long paddr = pfn << PAGE_SHIFT;



			pte_val(*pte) = (paddr | pte_base);



			start += PAGE_SIZE;

			pte++;

			pfn++;

		}

	}

static int pcpu_cpu_distance(unsigned int from, unsigned int to)

{

	if (cpu_to_node(from) == cpu_to_node(to))

		return LOCAL_DISTANCE;

	else

		return REMOTE_DISTANCE;

}



void __init setup_per_cpu_areas(void)

{

	static struct vm_struct vm;

	struct pcpu_alloc_info *ai;

	unsigned long delta, cpu;

	size_t size_sum;

	size_t ptrs_size;

	void **ptrs;

	unsigned long delta;

	unsigned int cpu;

	int rc;



	ai = pcpu_alloc_alloc_info(1, nr_cpu_ids);



	ai->static_size = __per_cpu_end - __per_cpu_start;

	ai->reserved_size = PERCPU_MODULE_RESERVE;



	size_sum = PFN_ALIGN(ai->static_size + ai->reserved_size +

			     PERCPU_DYNAMIC_RESERVE);



	ai->dyn_size = size_sum - ai->static_size - ai->reserved_size;

	ai->unit_size = PCPU_CHUNK_SIZE;

	ai->atom_size = PCPU_CHUNK_SIZE;

	ai->alloc_size = PCPU_CHUNK_SIZE;

	ai->groups[0].nr_units = nr_cpu_ids;



	for_each_possible_cpu(cpu)

		ai->groups[0].cpu_map[cpu] = cpu;



	ptrs_size = PFN_ALIGN(nr_cpu_ids * sizeof(ptrs[0]));

	ptrs = alloc_bootmem(ptrs_size);



	for_each_possible_cpu(cpu) {

		ptrs[cpu] = pcpu_alloc_bootmem(cpu, PCPU_CHUNK_SIZE,

					       PCPU_CHUNK_SIZE);



		free_bootmem(__pa(ptrs[cpu] + size_sum),

			     PCPU_CHUNK_SIZE - size_sum);



		memcpy(ptrs[cpu], __per_cpu_load, ai->static_size);

	}



	/* allocate address and map */

	vm.flags = VM_ALLOC;

	vm.size = nr_cpu_ids * PCPU_CHUNK_SIZE;

	vm_area_register_early(&vm, PCPU_CHUNK_SIZE);



	for_each_possible_cpu(cpu) {

		unsigned long start = (unsigned long) vm.addr;

		unsigned long end;



		start += cpu * PCPU_CHUNK_SIZE;

		end = start + PCPU_CHUNK_SIZE;

		pcpu_map_range(start, end, virt_to_page(ptrs[cpu]));

	}



	rc = pcpu_setup_first_chunk(ai, vm.addr);

	rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,

				    PERCPU_DYNAMIC_RESERVE, 4 << 20,

				    pcpu_cpu_distance, pcpu_alloc_bootmem,

				    pcpu_free_bootmem);

	if (rc)

		panic("failed to setup percpu first chunk (%d)", rc);



	free_bootmem(__pa(ptrs), ptrs_size);

		panic("failed to initialize first chunk (%d)", rc);



	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;

	for_each_possible_cpu(cpu)