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Commit 6563297c authored by Tejun Heo's avatar Tejun Heo
Browse files

percpu: use group information to allocate vmap areas sparsely 



ai->groups[] contains which units need to be put consecutively and at
what offset from the chunk base address.  Compile this information
into pcpu_group_offsets[] and pcpu_group_sizes[] in
pcpu_setup_first_chunk() and use them to allocate sparse vm areas
using pcpu_get_vm_areas().

This will be used to allow directly using sparse NUMA memories as
percpu areas.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
parent ca23e405

mm/percpu.c

+26 −9
Original line number Diff line number Diff line
@@ -98,7 +98,7 @@ struct pcpu_chunk { 
	int			map_used;	/* # of map entries used */

	int			map_alloc;	/* # of map entries allocated */

	int			*map;		/* allocation map */

	struct vm_struct	*vm;		/* mapped vmalloc region */

	struct vm_struct	**vms;		/* mapped vmalloc regions */

	bool			immutable;	/* no [de]population allowed */

	unsigned long		populated[];	/* populated bitmap */

};
@@ -106,7 +106,7 @@ struct pcpu_chunk { 
static int pcpu_unit_pages __read_mostly;

static int pcpu_unit_size __read_mostly;

static int pcpu_nr_units __read_mostly;

static int pcpu_chunk_size __read_mostly;

static int pcpu_atom_size __read_mostly;

static int pcpu_nr_slots __read_mostly;

static size_t pcpu_chunk_struct_size __read_mostly;
@@ -121,6 +121,11 @@ EXPORT_SYMBOL_GPL(pcpu_base_addr); 
static const int *pcpu_unit_map __read_mostly;		/* cpu -> unit */

const unsigned long *pcpu_unit_offsets __read_mostly;	/* cpu -> unit offset */



/* group information, used for vm allocation */

static int pcpu_nr_groups __read_mostly;

static const unsigned long *pcpu_group_offsets __read_mostly;

static const size_t *pcpu_group_sizes __read_mostly;



/*

 * The first chunk which always exists.  Note that unlike other

 * chunks, this one can be allocated and mapped in several different
@@ -988,8 +993,8 @@ static void free_pcpu_chunk(struct pcpu_chunk *chunk) 
{

	if (!chunk)

		return;

	if (chunk->vm)

		free_vm_area(chunk->vm);

	if (chunk->vms)

		pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups);

	pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));

	kfree(chunk);

}
@@ -1006,8 +1011,10 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void) 
	chunk->map_alloc = PCPU_DFL_MAP_ALLOC;

	chunk->map[chunk->map_used++] = pcpu_unit_size;



	chunk->vm = get_vm_area(pcpu_chunk_size, VM_ALLOC);

	if (!chunk->vm) {

	chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,

				       pcpu_nr_groups, pcpu_atom_size,

				       GFP_KERNEL);

	if (!chunk->vms) {

		free_pcpu_chunk(chunk);

		return NULL;

	}
@@ -1015,7 +1022,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void) 
	INIT_LIST_HEAD(&chunk->list);

	chunk->free_size = pcpu_unit_size;

	chunk->contig_hint = pcpu_unit_size;

	chunk->base_addr = chunk->vm->addr;

	chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0];



	return chunk;

}
@@ -1571,6 +1578,8 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 
	size_t dyn_size = ai->dyn_size;

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

	struct pcpu_chunk *schunk, *dchunk = NULL;

	unsigned long *group_offsets;

	size_t *group_sizes;

	unsigned long *unit_off;

	unsigned int cpu;

	int *unit_map;
@@ -1588,7 +1597,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 


	pcpu_dump_alloc_info(KERN_DEBUG, ai);



	/* determine number of units and initialize unit_map and base */

	/* process group information and build config tables accordingly */

	group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));

	group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));

	unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));

	unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
@@ -1599,6 +1610,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 
	for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {

		const struct pcpu_group_info *gi = &ai->groups[group];



		group_offsets[group] = gi->base_offset;

		group_sizes[group] = gi->nr_units * ai->unit_size;



		for (i = 0; i < gi->nr_units; i++) {

			cpu = gi->cpu_map[i];

			if (cpu == NR_CPUS)
@@ -1620,13 +1634,16 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 
	for_each_possible_cpu(cpu)

		BUG_ON(unit_map[cpu] == NR_CPUS);



	pcpu_nr_groups = ai->nr_groups;

	pcpu_group_offsets = group_offsets;

	pcpu_group_sizes = group_sizes;

	pcpu_unit_map = unit_map;

	pcpu_unit_offsets = unit_off;



	/* determine basic parameters */

	pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;

	pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;

	pcpu_chunk_size = pcpu_nr_units * pcpu_unit_size;

	pcpu_atom_size = ai->atom_size;

	pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +

		BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);