zram/xvmalloc: free bit block insertion optimization

This change is in a conditional block which is entered only when there is
an existing data block on the freelist where the insert has taken place.

The new block is pushed onto the freelist stack and this conditional block
is updating links in the prior stack head to point to the new stack head.
After this conditional block the first-/second-level indices are updated
to indicate that there is a free block at this location.

This patch adds an immediate return from the conditional block to avoid
setting bits again to indicate a free block on this freelist. The bits
would already be set because there was an existing free block on this
freelist.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/zram/xvmalloc.c b/drivers/staging/zram/xvmalloc.c
index 3ed744ba7ba01c8bbce3a993d868ec632854000c..9cbe04a496e1b88a895bf632a595fd34ee83b5e6 100644 (file)
--- a/drivers/staging/zram/xvmalloc.c
+++ b/drivers/staging/zram/xvmalloc.c
@@ -200,6 +200,8 @@ static void insert_block(struct xv_pool *pool, struct page *page, u32 offset,
                nextblock->link.prev_page = page;
                nextblock->link.prev_offset = offset;
                put_ptr_atomic(nextblock, KM_USER1);
+               /* If there was a next page then the free bits are set. */
+               return;
        }
 
        __set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]);