[PATCH 3/3] block: shrink bio size again
From: Christoph Hellwig <hch@lst.de>
Date: 2016-07-19 09:28:43
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
The recent ops split grew the bio by adding the new ioprio field. Shrink it again by using a 16-bit field for the bi_flags value and filling the holes near the beginning of the structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <redacted> Reviewed-by: Mike Christie <redacted> --- include/linux/blk_types.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 4494b6c..f254eb2 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h@@ -26,11 +26,11 @@ typedef void (bio_destructor_t) (struct bio *); struct bio { struct bio *bi_next; /* request queue link */ struct block_device *bi_bdev; - unsigned int bi_flags; /* status, command, etc */ int bi_error; unsigned int bi_rw; /* bottom bits req flags, * top bits REQ_OP */ + unsigned short bi_flags; /* status, command, etc */ unsigned short bi_ioprio; struct bvec_iter bi_iter;
@@ -116,7 +116,7 @@ struct bio { * Flags starting here get preserved by bio_reset() - this includes * BVEC_POOL_IDX() */ -#define BIO_RESET_BITS 13 +#define BIO_RESET_BITS 10 /* * We support 6 different bvec pools, the last one is magic in that it
@@ -131,7 +131,7 @@ struct bio { * freed. */ #define BVEC_POOL_BITS (4) -#define BVEC_POOL_OFFSET (32 - BVEC_POOL_BITS) +#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS) #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET) #endif /* CONFIG_BLOCK */
--
2.1.4