dm: lower bio-based mempool reservation (6cfa5857) · Commits · 戴 / test

Bio-based device mapper processing doesn't need larger mempools (like request-based DM does), so lower the number of reserved entries for bio-based operation. 16 was already used for bio-based DM's bioset but mistakenly wasn't used for it's _io_cache. Formalize difference between bio-based and request-based defaults by introducing RESERVED_BIO_BASED_IOS and RESERVED_REQUEST_BASED_IOS. (based on older code from Mikulas Patocka) Signed-off-by:

Mike Snitzer <snitzer@redhat.com> Signed-off-by:

Frank Mayhar <fmayhar@google.com> Acked-by:

Mikulas Patocka <mpatocka@redhat.com>

drivers/md/dm.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -211,7 +211,8 @@ struct dm_md_mempools {
		struct bio_set *bs;
		};

		#define MIN_IOS 256
		#define RESERVED_BIO_BASED_IOS 16
		#define RESERVED_REQUEST_BASED_IOS 256
		static struct kmem_cache *_io_cache;
		static struct kmem_cache *_rq_tio_cache;

		@@ -2873,18 +2874,18 @@ struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, u

		if (type == DM_TYPE_BIO_BASED) {
		cachep = _io_cache;
		pool_size = 16;
		pool_size = 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;
		pool_size = MIN_IOS;
		pool_size = RESERVED_REQUEST_BASED_IOS;
		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
		/* per_bio_data_size is not used. See __bind_mempools(). */
		WARN_ON(per_bio_data_size != 0);
		} else
		goto out;

		pools->io_pool = mempool_create_slab_pool(MIN_IOS, cachep);
		pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
		if (!pools->io_pool)
		goto out;

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