Commit de76fd89 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: remove the 1 and 4 vec bvec_slabs entries 



All bios with up to 4 bvecs use the inline bvecs in the bio itself, so
don't bother to define bvec_slabs entries for them.  Also decruftify
the bvec_slabs definition and initialization while we're at it.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f007a3d6

block/bio.c

+16 −37
Original line number Diff line number Diff line
@@ -25,23 +25,17 @@ 
#include "blk.h"

#include "blk-rq-qos.h"



struct biovec_slab {

static struct biovec_slab {

	int nr_vecs;

	char *name;

	struct kmem_cache *slab;

} bvec_slabs[] __read_mostly = {

	{ .nr_vecs = 16, .name = "biovec-16" },

	{ .nr_vecs = 64, .name = "biovec-64" },

	{ .nr_vecs = 128, .name = "biovec-128" },

	{ .nr_vecs = BIO_MAX_PAGES, .name = "biovec-max" },

};



/*

 * if you change this list, also change bvec_alloc or things will

 * break badly! cannot be bigger than what you can fit into an

 * unsigned short

 */

#define BV(x, n) { .nr_vecs = x, .name = "biovec-"#n }

static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {

	BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max),

};

#undef BV



/*

 * fs_bio_set is the bio_set containing bio and iovec memory pools used by

 * IO code that does not need private memory pools.
@@ -176,12 +170,7 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, 
	 * see comment near bvec_array define!

	 */

	switch (nr) {

	case 1:

		*idx = 0;

		break;

	case 2 ... 4:

		*idx = 1;

		break;

	/* smaller bios use inline vecs */

	case 5 ... 16:

		*idx = 2;

		break;
@@ -1613,31 +1602,21 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) 
}

EXPORT_SYMBOL(bioset_init_from_src);



static void __init biovec_init_slabs(void)

static int __init init_bio(void)

{

	int i;



	for (i = 0; i < BVEC_POOL_NR; i++) {

		int size;

		struct biovec_slab *bvs = bvec_slabs + i;

	BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET);



		if (bvs->nr_vecs <= BIO_INLINE_VECS) {

			bvs->slab = NULL;

			continue;

		}

	bio_integrity_init();



	for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) {

		struct biovec_slab *bvs = bvec_slabs + i;



		size = bvs->nr_vecs * sizeof(struct bio_vec);

		bvs->slab = kmem_cache_create(bvs->name, size, 0,

		bvs->slab = kmem_cache_create(bvs->name,

				bvs->nr_vecs * sizeof(struct bio_vec), 0,

				SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);

	}

}



static int __init init_bio(void)

{

	BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET);



	bio_integrity_init();

	biovec_init_slabs();



	if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS))

		panic("bio: can't allocate bios\n");