[PATCH 02/10] block: Convert bio_set to mempool_init()

From: Kent Overstreet
Date: Tue May 08 2018 - 21:34:30 EST


Minor performance improvement by getting rid of pointer indirections
from allocation/freeing fastpaths.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
block/bio-integrity.c | 29 ++++++++++++++---------------
block/bio.c | 36 +++++++++++++++++-------------------
include/linux/bio.h | 10 +++++-----
3 files changed, 36 insertions(+), 39 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 9cfdd6c83b..add7c7c853 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -56,12 +56,12 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
struct bio_set *bs = bio->bi_pool;
unsigned inline_vecs;

- if (!bs || !bs->bio_integrity_pool) {
+ if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
bip = kmalloc(sizeof(struct bio_integrity_payload) +
sizeof(struct bio_vec) * nr_vecs, gfp_mask);
inline_vecs = nr_vecs;
} else {
- bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
+ bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
inline_vecs = BIP_INLINE_VECS;
}

@@ -74,7 +74,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
unsigned long idx = 0;

bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
- bs->bvec_integrity_pool);
+ &bs->bvec_integrity_pool);
if (!bip->bip_vec)
goto err;
bip->bip_max_vcnt = bvec_nr_vecs(idx);
@@ -90,7 +90,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,

return bip;
err:
- mempool_free(bip, bs->bio_integrity_pool);
+ mempool_free(bip, &bs->bio_integrity_pool);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(bio_integrity_alloc);
@@ -111,10 +111,10 @@ static void bio_integrity_free(struct bio *bio)
kfree(page_address(bip->bip_vec->bv_page) +
bip->bip_vec->bv_offset);

- if (bs && bs->bio_integrity_pool) {
- bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);
+ if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
+ bvec_free(&bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);

- mempool_free(bip, bs->bio_integrity_pool);
+ mempool_free(bip, &bs->bio_integrity_pool);
} else {
kfree(bip);
}
@@ -465,16 +465,15 @@ EXPORT_SYMBOL(bio_integrity_clone);

int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
- if (bs->bio_integrity_pool)
+ if (mempool_initialized(&bs->bio_integrity_pool))
return 0;

- bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab);
- if (!bs->bio_integrity_pool)
+ if (mempool_init_slab_pool(&bs->bio_integrity_pool,
+ pool_size, bip_slab))
return -1;

- bs->bvec_integrity_pool = biovec_create_pool(pool_size);
- if (!bs->bvec_integrity_pool) {
- mempool_destroy(bs->bio_integrity_pool);
+ if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
+ mempool_exit(&bs->bio_integrity_pool);
return -1;
}

@@ -484,8 +483,8 @@ EXPORT_SYMBOL(bioset_integrity_create);

void bioset_integrity_free(struct bio_set *bs)
{
- mempool_destroy(bs->bio_integrity_pool);
- mempool_destroy(bs->bvec_integrity_pool);
+ mempool_exit(&bs->bio_integrity_pool);
+ mempool_exit(&bs->bvec_integrity_pool);
}
EXPORT_SYMBOL(bioset_integrity_free);

diff --git a/block/bio.c b/block/bio.c
index e1708db482..360e9bcea5 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -254,7 +254,7 @@ static void bio_free(struct bio *bio)
bio_uninit(bio);

if (bs) {
- bvec_free(bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));
+ bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));

/*
* If we have front padding, adjust the bio pointer before freeing
@@ -262,7 +262,7 @@ static void bio_free(struct bio *bio)
p = bio;
p -= bs->front_pad;

- mempool_free(p, bs->bio_pool);
+ mempool_free(p, &bs->bio_pool);
} else {
/* Bio was allocated by bio_kmalloc() */
kfree(bio);
@@ -454,7 +454,8 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
inline_vecs = nr_iovecs;
} else {
/* should not use nobvec bioset for nr_iovecs > 0 */
- if (WARN_ON_ONCE(!bs->bvec_pool && nr_iovecs > 0))
+ if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) &&
+ nr_iovecs > 0))
return NULL;
/*
* generic_make_request() converts recursion to iteration; this
@@ -483,11 +484,11 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
bs->rescue_workqueue)
gfp_mask &= ~__GFP_DIRECT_RECLAIM;

- p = mempool_alloc(bs->bio_pool, gfp_mask);
+ p = mempool_alloc(&bs->bio_pool, gfp_mask);
if (!p && gfp_mask != saved_gfp) {
punt_bios_to_rescuer(bs);
gfp_mask = saved_gfp;
- p = mempool_alloc(bs->bio_pool, gfp_mask);
+ p = mempool_alloc(&bs->bio_pool, gfp_mask);
}

front_pad = bs->front_pad;
@@ -503,11 +504,11 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
if (nr_iovecs > inline_vecs) {
unsigned long idx = 0;

- bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool);
if (!bvl && gfp_mask != saved_gfp) {
punt_bios_to_rescuer(bs);
gfp_mask = saved_gfp;
- bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool);
}

if (unlikely(!bvl))
@@ -524,7 +525,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
return bio;

err_free:
- mempool_free(p, bs->bio_pool);
+ mempool_free(p, &bs->bio_pool);
return NULL;
}
EXPORT_SYMBOL(bio_alloc_bioset);
@@ -1848,11 +1849,11 @@ EXPORT_SYMBOL_GPL(bio_trim);
* create memory pools for biovec's in a bio_set.
* use the global biovec slabs created for general use.
*/
-mempool_t *biovec_create_pool(int pool_entries)
+int biovec_init_pool(mempool_t *pool, int pool_entries)
{
struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;

- return mempool_create_slab_pool(pool_entries, bp->slab);
+ return mempool_init_slab_pool(pool, pool_entries, bp->slab);
}

void bioset_free(struct bio_set *bs)
@@ -1860,8 +1861,8 @@ void bioset_free(struct bio_set *bs)
if (bs->rescue_workqueue)
destroy_workqueue(bs->rescue_workqueue);

- mempool_destroy(bs->bio_pool);
- mempool_destroy(bs->bvec_pool);
+ mempool_exit(&bs->bio_pool);
+ mempool_exit(&bs->bvec_pool);

bioset_integrity_free(bs);
bio_put_slab(bs);
@@ -1913,15 +1914,12 @@ struct bio_set *bioset_create(unsigned int pool_size,
return NULL;
}

- bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab);
- if (!bs->bio_pool)
+ if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab))
goto bad;

- if (flags & BIOSET_NEED_BVECS) {
- bs->bvec_pool = biovec_create_pool(pool_size);
- if (!bs->bvec_pool)
- goto bad;
- }
+ if ((flags & BIOSET_NEED_BVECS) &&
+ biovec_init_pool(&bs->bvec_pool, pool_size))
+ goto bad;

if (!(flags & BIOSET_NEED_RESCUER))
return bs;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ce547a25e8..720f7261d0 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -412,7 +412,7 @@ enum {
BIOSET_NEED_RESCUER = BIT(1),
};
extern void bioset_free(struct bio_set *);
-extern mempool_t *biovec_create_pool(int pool_entries);
+extern int biovec_init_pool(mempool_t *pool, int pool_entries);

extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
extern void bio_put(struct bio *);
@@ -722,11 +722,11 @@ struct bio_set {
struct kmem_cache *bio_slab;
unsigned int front_pad;

- mempool_t *bio_pool;
- mempool_t *bvec_pool;
+ mempool_t bio_pool;
+ mempool_t bvec_pool;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
- mempool_t *bio_integrity_pool;
- mempool_t *bvec_integrity_pool;
+ mempool_t bio_integrity_pool;
+ mempool_t bvec_integrity_pool;
#endif

/*
--
2.17.0