dm: improve performance by moving dm_io structure to per-bio-data
Eliminates need for a separate mempool to allocate 'struct dm_io' objects from. As such, it saves an extra mempool allocation for each original bio that DM core is issued. This complicates the per-bio-data accessor functions by needing to conditonally add extra padding to get to a target's per-bio-data. But in the end this provides a decent performance improvement for all bio-based DM devices. On an NVMe-loop based testbed to a ramdisk (~3100 MB/s): bio-based DM linear performance improved by 2% (went from 2665 to 2777 MB/s). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer
Родитель
745dc570b2
Коммит
64f52b0e31
|
|
@ -91,6 +91,7 @@ struct mapped_device {
|
|||
/*
|
||||
* io objects are allocated from here.
|
||||
*/
|
||||
struct bio_set *io_bs;
|
||||
mempool_t *io_pool;
|
||||
|
||||
struct bio_set *bs;
|
||||
|
|
|
|||
171
drivers/md/dm.c
171
drivers/md/dm.c
|
|
@ -60,9 +60,38 @@ void dm_issue_global_event(void)
|
|||
}
|
||||
|
||||
/*
|
||||
* One of these is allocated per original bio.
|
||||
* One of these is allocated (on-stack) per original bio.
|
||||
*/
|
||||
struct clone_info {
|
||||
struct mapped_device *md;
|
||||
struct dm_table *map;
|
||||
struct bio *bio;
|
||||
struct dm_io *io;
|
||||
sector_t sector;
|
||||
unsigned sector_count;
|
||||
};
|
||||
|
||||
/*
|
||||
* One of these is allocated per clone bio.
|
||||
*/
|
||||
#define DM_TIO_MAGIC 7282014
|
||||
struct dm_target_io {
|
||||
unsigned magic;
|
||||
struct dm_io *io;
|
||||
struct dm_target *ti;
|
||||
unsigned target_bio_nr;
|
||||
unsigned *len_ptr;
|
||||
bool inside_dm_io;
|
||||
struct bio clone;
|
||||
};
|
||||
|
||||
/*
|
||||
* One of these is allocated per original bio.
|
||||
* It contains the first clone used for that original.
|
||||
*/
|
||||
#define DM_IO_MAGIC 5191977
|
||||
struct dm_io {
|
||||
unsigned magic;
|
||||
struct mapped_device *md;
|
||||
blk_status_t status;
|
||||
atomic_t io_count;
|
||||
|
|
@ -70,8 +99,35 @@ struct dm_io {
|
|||
unsigned long start_time;
|
||||
spinlock_t endio_lock;
|
||||
struct dm_stats_aux stats_aux;
|
||||
/* last member of dm_target_io is 'struct bio' */
|
||||
struct dm_target_io tio;
|
||||
};
|
||||
|
||||
void *dm_per_bio_data(struct bio *bio, size_t data_size)
|
||||
{
|
||||
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
|
||||
if (!tio->inside_dm_io)
|
||||
return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
|
||||
return (char *)bio - offsetof(struct dm_target_io, clone) - offsetof(struct dm_io, tio) - data_size;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(dm_per_bio_data);
|
||||
|
||||
struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
|
||||
{
|
||||
struct dm_io *io = (struct dm_io *)((char *)data + data_size);
|
||||
if (io->magic == DM_IO_MAGIC)
|
||||
return (struct bio *)((char *)io + offsetof(struct dm_io, tio) + offsetof(struct dm_target_io, clone));
|
||||
BUG_ON(io->magic != DM_TIO_MAGIC);
|
||||
return (struct bio *)((char *)io + offsetof(struct dm_target_io, clone));
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
|
||||
|
||||
unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
|
||||
{
|
||||
return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
|
||||
|
||||
#define MINOR_ALLOCED ((void *)-1)
|
||||
|
||||
/*
|
||||
|
|
@ -95,6 +151,7 @@ static int dm_numa_node = DM_NUMA_NODE;
|
|||
struct dm_md_mempools {
|
||||
mempool_t *io_pool;
|
||||
struct bio_set *bs;
|
||||
struct bio_set *io_bs;
|
||||
};
|
||||
|
||||
struct table_device {
|
||||
|
|
@ -488,16 +545,58 @@ out:
|
|||
|
||||
static struct dm_io *alloc_io(struct mapped_device *md)
|
||||
{
|
||||
return mempool_alloc(md->io_pool, GFP_NOIO);
|
||||
struct dm_io *io;
|
||||
struct dm_target_io *tio;
|
||||
struct bio *clone;
|
||||
|
||||
clone = bio_alloc_bioset(GFP_NOIO, 0, md->io_bs);
|
||||
if (!clone)
|
||||
return NULL;
|
||||
|
||||
tio = container_of(clone, struct dm_target_io, clone);
|
||||
tio->inside_dm_io = true;
|
||||
tio->io = NULL;
|
||||
|
||||
io = container_of(tio, struct dm_io, tio);
|
||||
io->magic = DM_IO_MAGIC;
|
||||
|
||||
return io;
|
||||
}
|
||||
|
||||
static void free_io(struct mapped_device *md, struct dm_io *io)
|
||||
{
|
||||
mempool_free(io, md->io_pool);
|
||||
bio_put(&io->tio.clone);
|
||||
}
|
||||
|
||||
static struct dm_target_io *alloc_tio(struct clone_info *ci, struct dm_target *ti,
|
||||
unsigned target_bio_nr, gfp_t gfp_mask)
|
||||
{
|
||||
struct dm_target_io *tio;
|
||||
|
||||
if (!ci->io->tio.io) {
|
||||
/* the dm_target_io embedded in ci->io is available */
|
||||
tio = &ci->io->tio;
|
||||
} else {
|
||||
struct bio *clone = bio_alloc_bioset(gfp_mask, 0, ci->md->bs);
|
||||
if (!clone)
|
||||
return NULL;
|
||||
|
||||
tio = container_of(clone, struct dm_target_io, clone);
|
||||
tio->inside_dm_io = false;
|
||||
}
|
||||
|
||||
tio->magic = DM_TIO_MAGIC;
|
||||
tio->io = ci->io;
|
||||
tio->ti = ti;
|
||||
tio->target_bio_nr = target_bio_nr;
|
||||
|
||||
return tio;
|
||||
}
|
||||
|
||||
static void free_tio(struct dm_target_io *tio)
|
||||
{
|
||||
if (tio->inside_dm_io)
|
||||
return;
|
||||
bio_put(&tio->clone);
|
||||
}
|
||||
|
||||
|
|
@ -1110,6 +1209,7 @@ static void __map_bio(struct dm_target_io *tio)
|
|||
int r;
|
||||
sector_t sector;
|
||||
struct bio *clone = &tio->clone;
|
||||
struct dm_io *io = tio->io;
|
||||
struct dm_target *ti = tio->ti;
|
||||
|
||||
clone->bi_end_io = clone_endio;
|
||||
|
|
@ -1119,7 +1219,7 @@ static void __map_bio(struct dm_target_io *tio)
|
|||
* anything, the target has assumed ownership of
|
||||
* this io.
|
||||
*/
|
||||
atomic_inc(&tio->io->io_count);
|
||||
atomic_inc(&io->io_count);
|
||||
sector = clone->bi_iter.bi_sector;
|
||||
|
||||
r = ti->type->map(ti, clone);
|
||||
|
|
@ -1129,16 +1229,16 @@ static void __map_bio(struct dm_target_io *tio)
|
|||
case DM_MAPIO_REMAPPED:
|
||||
/* the bio has been remapped so dispatch it */
|
||||
trace_block_bio_remap(clone->bi_disk->queue, clone,
|
||||
bio_dev(tio->io->orig_bio), sector);
|
||||
bio_dev(io->orig_bio), sector);
|
||||
generic_make_request(clone);
|
||||
break;
|
||||
case DM_MAPIO_KILL:
|
||||
dec_pending(tio->io, BLK_STS_IOERR);
|
||||
free_tio(tio);
|
||||
dec_pending(io, BLK_STS_IOERR);
|
||||
break;
|
||||
case DM_MAPIO_REQUEUE:
|
||||
dec_pending(tio->io, BLK_STS_DM_REQUEUE);
|
||||
free_tio(tio);
|
||||
dec_pending(io, BLK_STS_DM_REQUEUE);
|
||||
break;
|
||||
default:
|
||||
DMWARN("unimplemented target map return value: %d", r);
|
||||
|
|
@ -1146,15 +1246,6 @@ static void __map_bio(struct dm_target_io *tio)
|
|||
}
|
||||
}
|
||||
|
||||
struct clone_info {
|
||||
struct mapped_device *md;
|
||||
struct dm_table *map;
|
||||
struct bio *bio;
|
||||
struct dm_io *io;
|
||||
sector_t sector;
|
||||
unsigned sector_count;
|
||||
};
|
||||
|
||||
static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
|
||||
{
|
||||
bio->bi_iter.bi_sector = sector;
|
||||
|
|
@ -1197,24 +1288,6 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static struct dm_target_io *alloc_tio(struct clone_info *ci, struct dm_target *ti,
|
||||
unsigned target_bio_nr, gfp_t gfp_mask)
|
||||
{
|
||||
struct dm_target_io *tio;
|
||||
struct bio *clone;
|
||||
|
||||
clone = bio_alloc_bioset(gfp_mask, 0, ci->md->bs);
|
||||
if (!clone)
|
||||
return NULL;
|
||||
|
||||
tio = container_of(clone, struct dm_target_io, clone);
|
||||
tio->io = ci->io;
|
||||
tio->ti = ti;
|
||||
tio->target_bio_nr = target_bio_nr;
|
||||
|
||||
return tio;
|
||||
}
|
||||
|
||||
static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
|
||||
struct dm_target *ti, unsigned num_bios)
|
||||
{
|
||||
|
|
@ -1628,6 +1701,8 @@ static void cleanup_mapped_device(struct mapped_device *md)
|
|||
mempool_destroy(md->io_pool);
|
||||
if (md->bs)
|
||||
bioset_free(md->bs);
|
||||
if (md->io_bs)
|
||||
bioset_free(md->io_bs);
|
||||
|
||||
if (md->dax_dev) {
|
||||
kill_dax(md->dax_dev);
|
||||
|
|
@ -1793,15 +1868,19 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
|
|||
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
|
||||
|
||||
if (dm_table_bio_based(t)) {
|
||||
/* The md may already have mempools that need changing. */
|
||||
/*
|
||||
* The md may already have mempools that need changing.
|
||||
* If so, reload bioset because front_pad may have changed
|
||||
* because a different table was loaded.
|
||||
*/
|
||||
if (md->bs) {
|
||||
/*
|
||||
* Reload bioset because front_pad may have changed
|
||||
* because a different table was loaded.
|
||||
*/
|
||||
bioset_free(md->bs);
|
||||
md->bs = NULL;
|
||||
}
|
||||
if (md->io_bs) {
|
||||
bioset_free(md->io_bs);
|
||||
md->io_bs = NULL;
|
||||
}
|
||||
if (md->io_pool) {
|
||||
/*
|
||||
* Reload io_pool because pool_size may have changed
|
||||
|
|
@ -1823,12 +1902,14 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
|
|||
goto out;
|
||||
}
|
||||
|
||||
BUG_ON(!p || md->io_pool || md->bs);
|
||||
BUG_ON(!p || md->io_pool || md->bs || md->io_bs);
|
||||
|
||||
md->io_pool = p->io_pool;
|
||||
p->io_pool = NULL;
|
||||
md->bs = p->bs;
|
||||
p->bs = NULL;
|
||||
md->io_bs = p->io_bs;
|
||||
p->io_bs = NULL;
|
||||
out:
|
||||
/* mempool bind completed, no longer need any mempools in the table */
|
||||
dm_table_free_md_mempools(t);
|
||||
|
|
@ -2719,7 +2800,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_qu
|
|||
{
|
||||
struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
|
||||
unsigned int pool_size = 0;
|
||||
unsigned int front_pad;
|
||||
unsigned int front_pad, io_front_pad;
|
||||
|
||||
if (!pools)
|
||||
return NULL;
|
||||
|
|
@ -2729,6 +2810,12 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_qu
|
|||
case DM_TYPE_DAX_BIO_BASED:
|
||||
pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
|
||||
front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
|
||||
io_front_pad = roundup(front_pad, __alignof__(struct dm_io)) + offsetof(struct dm_io, tio);
|
||||
pools->io_bs = bioset_create(pool_size, io_front_pad, 0);
|
||||
if (!pools->io_bs)
|
||||
goto out;
|
||||
if (integrity && bioset_integrity_create(pools->io_bs, pool_size))
|
||||
goto out;
|
||||
pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
|
||||
if (!pools->io_pool)
|
||||
goto out;
|
||||
|
|
@ -2767,6 +2854,8 @@ void dm_free_md_mempools(struct dm_md_mempools *pools)
|
|||
|
||||
if (pools->bs)
|
||||
bioset_free(pools->bs);
|
||||
if (pools->io_bs)
|
||||
bioset_free(pools->io_bs);
|
||||
|
||||
kfree(pools);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -314,35 +314,9 @@ struct dm_target_callbacks {
|
|||
int (*congested_fn) (struct dm_target_callbacks *, int);
|
||||
};
|
||||
|
||||
/*
|
||||
* For bio-based dm.
|
||||
* One of these is allocated for each bio.
|
||||
* This structure shouldn't be touched directly by target drivers.
|
||||
* It is here so that we can inline dm_per_bio_data and
|
||||
* dm_bio_from_per_bio_data
|
||||
*/
|
||||
struct dm_target_io {
|
||||
struct dm_io *io;
|
||||
struct dm_target *ti;
|
||||
unsigned target_bio_nr;
|
||||
unsigned *len_ptr;
|
||||
struct bio clone;
|
||||
};
|
||||
|
||||
static inline void *dm_per_bio_data(struct bio *bio, size_t data_size)
|
||||
{
|
||||
return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
|
||||
}
|
||||
|
||||
static inline struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
|
||||
{
|
||||
return (struct bio *)((char *)data + data_size + offsetof(struct dm_target_io, clone));
|
||||
}
|
||||
|
||||
static inline unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
|
||||
{
|
||||
return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
|
||||
}
|
||||
void *dm_per_bio_data(struct bio *bio, size_t data_size);
|
||||
struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
|
||||
unsigned dm_bio_get_target_bio_nr(const struct bio *bio);
|
||||
|
||||
int dm_register_target(struct target_type *t);
|
||||
void dm_unregister_target(struct target_type *t);
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче