From e8603136cb04ec2d0c9b4b5be7a071fc003cb399 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Sep 2013 18:06:12 -0400 Subject: [PATCH] dm: add reserved_bio_based_ios module parameter Allow user to change the number of IOs that are reserved by bio-based DM's mempools by writing to this file: /sys/module/dm_mod/parameters/reserved_bio_based_ios The default value is RESERVED_BIO_BASED_IOS (16). The maximum allowed value is RESERVED_MAX_IOS (1024). Export dm_get_reserved_bio_based_ios() for use by DM targets and core code. Switch to sizing dm-io's mempool and bioset using DM core's configurable 'reserved_bio_based_ios'. Signed-off-by: Mike Snitzer Signed-off-by: Frank Mayhar --- drivers/md/dm-io.c | 7 +++---- drivers/md/dm.c | 17 ++++++++++++++++- drivers/md/dm.h | 1 + 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index ea49834377c8..2a20986a2fec 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -19,8 +19,6 @@ #define DM_MSG_PREFIX "io" #define DM_IO_MAX_REGIONS BITS_PER_LONG -#define MIN_IOS 16 -#define MIN_BIOS 16 struct dm_io_client { mempool_t *pool; @@ -50,16 +48,17 @@ static struct kmem_cache *_dm_io_cache; struct dm_io_client *dm_io_client_create(void) { struct dm_io_client *client; + unsigned min_ios = dm_get_reserved_bio_based_ios(); client = kmalloc(sizeof(*client), GFP_KERNEL); if (!client) return ERR_PTR(-ENOMEM); - client->pool = mempool_create_slab_pool(MIN_IOS, _dm_io_cache); + client->pool = mempool_create_slab_pool(min_ios, _dm_io_cache); if (!client->pool) goto bad; - client->bios = bioset_create(MIN_BIOS, 0); + client->bios = bioset_create(min_ios, 0); if (!client->bios) goto bad; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 1e85f1da1ef3..b3e26c7d1417 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -217,6 +217,11 @@ struct dm_md_mempools { static struct kmem_cache *_io_cache; static struct kmem_cache *_rq_tio_cache; +/* + * Bio-based DM's mempools' reserved IOs set by the user. + */ +static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; + /* * Request-based DM's mempools' reserved IOs set by the user. */ @@ -241,6 +246,13 @@ static unsigned __dm_get_reserved_ios(unsigned *reserved_ios, return ios; } +unsigned dm_get_reserved_bio_based_ios(void) +{ + return __dm_get_reserved_ios(&reserved_bio_based_ios, + RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS); +} +EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); + unsigned dm_get_reserved_rq_based_ios(void) { return __dm_get_reserved_ios(&reserved_rq_based_ios, @@ -2906,7 +2918,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, u if (type == DM_TYPE_BIO_BASED) { cachep = _io_cache; - pool_size = RESERVED_BIO_BASED_IOS; + pool_size = dm_get_reserved_bio_based_ios(); front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone); } else if (type == DM_TYPE_REQUEST_BASED) { cachep = _rq_tio_cache; @@ -2969,6 +2981,9 @@ module_exit(dm_exit); module_param(major, uint, 0); MODULE_PARM_DESC(major, "The major number of the device mapper"); +module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); + module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools"); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 15396501e0b3..1d1ad7b7e527 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -184,6 +184,7 @@ void dm_free_md_mempools(struct dm_md_mempools *pools); /* * Helpers that are used by DM core */ +unsigned dm_get_reserved_bio_based_ios(void); unsigned dm_get_reserved_rq_based_ios(void); static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) -- 2.20.1