Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu

#define PCPU_MIN_ALLOC_SHIFT		2

#define PCPU_MIN_ALLOC_SIZE		(1 << PCPU_MIN_ALLOC_SHIFT)

/* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */

#define PCPU_BITS_PER_PAGE		(PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)

/*

 * This determines the size of each metadata block.  There are several subtle

 * constraints around this constant.  The reserved region must be a multiple of

 * PCPU_BITMAP_BLOCK_SIZE.  Additionally, PCPU_BITMAP_BLOCK_SIZE must be a

 * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of

 * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size

 * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.

 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the

 * updating of hints is used to manage the nr_empty_pop_pages in both

 * the chunk and globally.

 */

#define PCPU_BITMAP_BLOCK_SIZE		PAGE_SIZE

#define PCPU_BITMAP_BLOCK_BITS		(PCPU_BITMAP_BLOCK_SIZE >>	\

 * pcpu_block_md is the metadata block struct.

 * Each chunk's bitmap is split into a number of full blocks.

 * All units are in terms of bits.

 *

 * The scan hint is the largest known contiguous area before the contig hint.

 * It is not necessarily the actual largest contig hint though.  There is an

 * invariant that the scan_hint_start > contig_hint_start iff

 * scan_hint == contig_hint.  This is necessary because when scanning forward,

 * we don't know if a new contig hint would be better than the current one.

 */

struct pcpu_block_md {

	int			scan_hint;	/* scan hint for block */

	int			scan_hint_start; /* block relative starting

						    position of the scan hint */

	int                     contig_hint;    /* contig hint for block */

	int                     contig_hint_start; /* block relative starting

						      position of the contig hint */

	int                     right_free;     /* size of free space along

						   the right side of the block */

	int                     first_free;     /* block position of first free */

	int			nr_bits;	/* total bits responsible for */

};

struct pcpu_chunk {

	struct list_head	list;		/* linked to pcpu_slot lists */

	int			free_bytes;	/* free bytes in the chunk */

	int			contig_bits;	/* max contiguous size hint */

	int			contig_bits_start; /* contig_bits starting

						      offset */

	struct pcpu_block_md	chunk_md;

	void			*base_addr;	/* base address of this chunk */

	unsigned long		*alloc_map;	/* allocation map */

	struct pcpu_block_md	*md_blocks;	/* metadata blocks */

	void			*data;		/* chunk data */

	int			first_bit;	/* no free below this */

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

	int			start_offset;	/* the overlap with the previous

						   region to have a page aligned

	chunk->base_addr = page_address(pages);

	spin_lock_irqsave(&pcpu_lock, flags);

	pcpu_chunk_populated(chunk, 0, nr_pages, false);

	pcpu_chunk_populated(chunk, 0, nr_pages);

	spin_unlock_irqrestore(&pcpu_lock, flags);

	pcpu_stats_chunk_alloc();

static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,

			    int *buffer)

{

	struct pcpu_block_md *chunk_md = &chunk->chunk_md;

	int i, last_alloc, as_len, start, end;

	int *alloc_sizes, *p;

	/* statistics */

	P("nr_alloc", chunk->nr_alloc);

	P("max_alloc_size", chunk->max_alloc_size);

	P("empty_pop_pages", chunk->nr_empty_pop_pages);

	P("first_bit", chunk->first_bit);

	P("first_bit", chunk_md->first_free);

	P("free_bytes", chunk->free_bytes);

	P("contig_bytes", chunk->contig_bits * PCPU_MIN_ALLOC_SIZE);

	P("contig_bytes", chunk_md->contig_hint * PCPU_MIN_ALLOC_SIZE);

	P("sum_frag", sum_frag);

	P("max_frag", max_frag);

	P("cur_min_alloc", cur_min_alloc);