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authorMike Snitzer <snitzer@redhat.com>2013-09-12 18:06:12 -0400
committerMike Snitzer <snitzer@redhat.com>2013-09-23 10:42:24 -0400
commite8603136cb04ec2d0c9b4b5be7a071fc003cb399 (patch)
treee642b195034f281eeb76de62f5bcf3deb2985de1 /drivers/md/dm.c
parentf47908269fb53d522a956b78612a0037f5faf8e7 (diff)
downloadlinux-e8603136cb04ec2d0c9b4b5be7a071fc003cb399.tar.gz
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 <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c17
1 files changed, 16 insertions, 1 deletions
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
@@ -218,6 +218,11 @@ 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.
  */
 static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
@@ -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");