From mboxrd@z Thu Jan 1 00:00:00 1970 From: martin.petersen@oracle.com (Martin K. Petersen) Date: Tue, 21 Jul 2015 02:02:57 -0400 Subject: [PATCH 3/5] block: Reduce the size of struct blk_integrity In-Reply-To: <1437458579-18706-1-git-send-email-martin.petersen@oracle.com> References: <20150716091957.GA18310@infradead.org> <1437458579-18706-1-git-send-email-martin.petersen@oracle.com> Message-ID: <1437458579-18706-4-git-send-email-martin.petersen@oracle.com> The per-device properties in the blk_integrity structure were previously unsigned short. However, most of the values fit inside a char. The only exception is the data interval size and we can work around that by storing it as a power of two. This cuts the size of the dynamic portion of blk_integrity in half. Signed-off-by: Martin K. Petersen Reported-by: Christoph Hellwig --- block/bio-integrity.c | 4 ++-- block/blk-integrity.c | 6 +++--- include/linux/blkdev.h | 8 ++++---- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/block/bio-integrity.c b/block/bio-integrity.c index f09531130cff..4da7fbc28845 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -197,7 +197,7 @@ EXPORT_SYMBOL(bio_integrity_enabled); static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi, unsigned int sectors) { - return sectors >> (ilog2(bi->interval) - 9); + return sectors >> (bi->interval_exp - 9); } static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi, @@ -224,7 +224,7 @@ static int bio_integrity_process(struct bio *bio, bip->bip_vec->bv_offset; iter.disk_name = bio->bi_bdev->bd_disk->disk_name; - iter.interval = bi->interval; + iter.interval = 1 << bi->interval_exp; iter.seed = bip_get_seed(bip); iter.prot_buf = prot_buf; diff --git a/block/blk-integrity.c b/block/blk-integrity.c index 5e5280d58c61..70ba9389d0dd 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -155,10 +155,10 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2) if (!b1 || !b2) return -1; - if (b1->interval != b2->interval) { + if (b1->interval_exp != b2->interval_exp) { pr_err("%s: %s/%s protection interval %u != %u\n", __func__, gd1->disk_name, gd2->disk_name, - b1->interval, b2->interval); + 1 << b1->interval_exp, 1 << b2->interval_exp); return -1; } @@ -437,7 +437,7 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template) kobject_uevent(&disk->integrity_kobj, KOBJ_ADD); bi->flags |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE; - bi->interval = queue_logical_block_size(disk->queue); + bi->interval_exp = ilog2(queue_logical_block_size(disk->queue)); disk->integrity = bi; } else bi = disk->integrity; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4fbb3b9f7f2e..c01ce2f7168b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1435,10 +1435,10 @@ struct blk_integrity_profile { struct blk_integrity { struct blk_integrity_profile *profile; - unsigned short flags; - unsigned short tuple_size; - unsigned short interval; - unsigned short tag_size; + unsigned char flags; + unsigned char tuple_size; + unsigned char interval_exp; + unsigned char tag_size; }; extern bool blk_integrity_is_initialized(struct gendisk *); -- 2.4.3