===================================================================
@@ -80,12 +80,12 @@ struct dm_verity_io {
/* original value of bio->bi_end_io */
bio_end_io_t *orig_bi_end_io;
+ struct bvec_iter iter;
+
sector_t block;
unsigned int n_blocks;
bool in_tasklet;
- struct bvec_iter iter;
-
struct work_struct work;
char *recheck_buffer;
===================================================================
@@ -53,11 +53,11 @@
struct convert_context {
struct completion restart;
struct bio *bio_in;
- struct bio *bio_out;
struct bvec_iter iter_in;
+ struct bio *bio_out;
struct bvec_iter iter_out;
- u64 cc_sector;
atomic_t cc_pending;
+ u64 cc_sector;
union {
struct skcipher_request *req;
struct aead_request *req_aead;
"struct bvec_iter" is defined with the __packed attribute, so it is aligned on a single byte. On X86 (and on other architectures that support unaligned addresses in hardware), "struct bvec_iter" is accessed using the 8-byte and 4-byte memory instructions, however these instructions are less efficient if they operate on unaligned addresses. (on RISC machines that don't have unaligned access in hardware, GCC generates byte-by-byte accesses that are very inefficient - see [1]) This commit reorders the entries in "struct dm_verity_io" and "struct convert_context", so that "struct bvec_iter" is aligned on 8 bytes. [1] https://lore.kernel.org/all/ZcLuWUNRZadJr0tQ@fedora/T/ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> --- drivers/md/dm-crypt.c | 4 ++-- drivers/md/dm-verity.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)