[dm-devel] [PATCH 5/7] dm mpath: use dm_get_reserved_rq_based_ios to size mempool

Mikulas Patocka mpatocka at redhat.com
Thu Sep 12 22:48:36 UTC 2013


Acked-by: Mikulas Patocka <mpatocka at redhat.com>

On Thu, 12 Sep 2013, Mike Snitzer wrote:

> Switch dm-mpath over to sizing its mempool using DM core's configurable
> 'reserved_rq_based_ios'.
> 
> Export dm_get_reserved_rq_based_ios() for use by DM targets and core
> code.
> 
> Signed-off-by: Mike Snitzer <snitzer at redhat.com>
> ---
>  drivers/md/dm-mpath.c |  6 +++---
>  drivers/md/dm.c       | 12 ++++++++++++
>  drivers/md/dm.h       |  1 +
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
> index 5adede1..ddef91f 100644
> --- a/drivers/md/dm-mpath.c
> +++ b/drivers/md/dm-mpath.c
> @@ -7,6 +7,7 @@
>  
>  #include <linux/device-mapper.h>
>  
> +#include "dm.h"
>  #include "dm-path-selector.h"
>  #include "dm-uevent.h"
>  
> @@ -116,8 +117,6 @@ struct dm_mpath_io {
>  
>  typedef int (*action_fn) (struct pgpath *pgpath);
>  
> -#define MIN_IOS 256	/* Mempool size */
> -
>  static struct kmem_cache *_mpio_cache;
>  
>  static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
> @@ -190,6 +189,7 @@ static void free_priority_group(struct priority_group *pg,
>  static struct multipath *alloc_multipath(struct dm_target *ti)
>  {
>  	struct multipath *m;
> +	unsigned min_ios = dm_get_reserved_rq_based_ios();
>  
>  	m = kzalloc(sizeof(*m), GFP_KERNEL);
>  	if (m) {
> @@ -202,7 +202,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
>  		INIT_WORK(&m->trigger_event, trigger_event);
>  		init_waitqueue_head(&m->pg_init_wait);
>  		mutex_init(&m->work_mutex);
> -		m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
> +		m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache);
>  		if (!m->mpio_pool) {
>  			kfree(m);
>  			return NULL;
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index 3f96c86..186f77d 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -287,6 +287,18 @@ static void __reserved_request_based_ios_refresh(void)
>  	}
>  }
>  
> +unsigned dm_get_reserved_rq_based_ios(void)
> +{
> +	unsigned ios;
> +
> +	mutex_lock(&dm_mempools_lock);
> +	ios = reserved_rq_based_ios_latch;
> +	mutex_unlock(&dm_mempools_lock);
> +
> +	return (ios ? : RESERVED_REQUEST_BASED_IOS);
> +}
> +EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
> +
>  static int __init local_init(void)
>  {
>  	int r = -ENOMEM;
> diff --git a/drivers/md/dm.h b/drivers/md/dm.h
> index e1982eb..1d1ad7b 100644
> --- a/drivers/md/dm.h
> +++ b/drivers/md/dm.h
> @@ -185,6 +185,7 @@ 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)
>  {
> -- 
> 1.8.1.4
> 




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