Convert zio_buf_alloc() consumers

In multiple cases zio_buf_alloc() was used instead of kmem_alloc()
or vmem_alloc().  This was often done because the allocations
could be large and it was easy to use zfs_buf_alloc() for them.

But this isn't ideal for allocations which are small or short
lived.  In these cases it is better to use kmem_alloc() or
vmem_alloc().  If possible we want to avoid the case where
we have slabs allocated for kmem caches which are rarely used.

Note for small allocations vmem_alloc() will be internally
converted to kmem_alloc().  Therefore as long as large
allocations are infrequent and short lived the penalty for
using vmem_alloc() is small.

Reviewed-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #5409 

1 files changed, 2 insertions, 2 deletions

diff --git a/module/zfs/sa.c b/module/zfs/sa.c
index 0df3b4755..d4f412c2a 100644
--- a/module/zfs/sa.c
+++ b/module/zfs/sa.c
@@ -1690,7 +1690,7 @@ sa_modify_attrs(sa_handle_t *hdl, sa_attr_type_t newattr,
 
 	if ((error = sa_get_spill(hdl)) == 0) {
 		spill_data_size = hdl->sa_spill->db_size;
-		old_data[1] = zio_buf_alloc(spill_data_size);
+		old_data[1] = vmem_alloc(spill_data_size, KM_SLEEP);
 		bcopy(hdl->sa_spill->db_data, old_data[1],
 		    hdl->sa_spill->db_size);
 		spill_attr_count =
@@ -1773,7 +1773,7 @@ sa_modify_attrs(sa_handle_t *hdl, sa_attr_type_t newattr,
 	if (old_data[0])
 		kmem_free(old_data[0], bonus_data_size);
 	if (old_data[1])
-		zio_buf_free(old_data[1], spill_data_size);
+		vmem_free(old_data[1], spill_data_size);
 	kmem_free(attr_desc, sizeof (sa_bulk_attr_t) * attr_count);
 
 	return (error);