>From e2693136fa64d5c9dde73d2d663bde84f8326877 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@xxxxxxxxxx>
Date: Wed, 10 Jul 2019 14:18:12 -0700
request->pre_start_time is currently only used by the iocost
controller. Let's omit the field if disabled and avoid wasting space
in struct request.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Suggested-by: Jens Axboe <axboe@xxxxxxxxx>
---
The git branch is updated accordingly.
Thanks.
block/blk-mq.c | 2 ++
include/linux/blkdev.h | 7 +++++++
2 files changed, 9 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 90b46988cc02..ce96bcd7e260 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -325,7 +325,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
RB_CLEAR_NODE(&rq->rb_node);
rq->rq_disk = NULL;
rq->part = NULL;
+#ifdef CONFIG_BLK_CGROUP_IOCOST
rq->pre_start_time_ns = pre_start_time_ns;
+#endif
if (blk_mq_need_time_stamp(rq))
rq->start_time_ns = ktime_get_ns();
else
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4247a9bc44b7..2425af6d3f5e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -194,8 +194,10 @@ struct request {
struct gendisk *rq_disk;
struct hd_struct *part;
+#ifdef CONFIG_BLK_CGROUP_IOCOST
/* Time that the first bio started allocating this request. */
u64 pre_start_time_ns;
+#endif
/* Time that this request was allocated for this IO. */
u64 start_time_ns;
/* Time that I/O was submitted to the device. */
@@ -635,8 +637,13 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
#define blk_queue_pci_p2pdma(q) \
test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
+
+#ifdef CONFIG_BLK_CGROUP_IOCOST
#define blk_queue_rec_prestart(q) \
test_bit(QUEUE_FLAG_REC_PRESTART, &(q)->queue_flags)
+#else
+#define blk_queue_rec_prestart(q) false
+#endif
#define blk_noretry_request(rq) \
((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
--
2.17.1
