From: Yu Kuai blkcg_bio_issue_init() is called for every bio, while initialized bio_issue_time is only used by io-latency. Add a new queue_flag and only set this flag when io-latency is initialized, so that extra blk_time_get_ns() from blkcg_bio_issue_init() can be saved for disks that io-latency is not enabled. Signed-off-by: Yu Kuai --- block/blk-cgroup.h | 5 ++++- block/blk-iolatency.c | 1 + block/blk-mq-debugfs.c | 1 + include/linux/blkdev.h | 1 + 4 files changed, 7 insertions(+), 1 deletion(-) diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index d73204d27d72..93e8a9fa76fe 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -372,7 +372,10 @@ static inline void blkg_put(struct blkcg_gq *blkg) static inline void blkcg_bio_issue_init(struct bio *bio) { - bio->issue_time_ns = blk_time_get_ns(); + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + + if (test_bit(QUEUE_FLAG_BIO_ISSUE, &q->queue_flags)) + bio->issue_time_ns = blk_time_get_ns(); } static inline void blkcg_use_delay(struct blkcg_gq *blkg) diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 554b191a6892..c9b3bd12c87c 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -767,6 +767,7 @@ static int blk_iolatency_init(struct gendisk *disk) if (ret) goto err_qos_del; + blk_queue_flag_set(QUEUE_FLAG_BIO_ISSUE, disk->queue); timer_setup(&blkiolat->timer, blkiolatency_timer_fn, 0); INIT_WORK(&blkiolat->enable_work, blkiolatency_enable_work_fn); diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 32c65efdda46..b192647456e1 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -96,6 +96,7 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(DISABLE_WBT_DEF), QUEUE_FLAG_NAME(NO_ELV_SWITCH), QUEUE_FLAG_NAME(QOS_ENABLED), + QUEUE_FLAG_NAME(BIO_ISSUE), }; #undef QUEUE_FLAG_NAME diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index fe1797bbec42..ca1dcf59cb32 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -657,6 +657,7 @@ enum { QUEUE_FLAG_DISABLE_WBT_DEF, /* for sched to disable/enable wbt */ QUEUE_FLAG_NO_ELV_SWITCH, /* can't switch elevator any more */ QUEUE_FLAG_QOS_ENABLED, /* qos is enabled */ + QUEUE_FLAG_BIO_ISSUE, /* track bio issue time */ QUEUE_FLAG_MAX }; -- 2.39.2