From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
To: linux-block@vger.kernel.org
Cc: hch@lst.de, axboe@kernel.dk,
Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Subject: [PATCH V3 2/6] null_blk: create a helper for throttling
Date: Tue, 20 Aug 2019 23:13:10 -0700 [thread overview]
Message-ID: <20190821061314.3262-3-chaitanya.kulkarni@wdc.com> (raw)
In-Reply-To: <20190821061314.3262-1-chaitanya.kulkarni@wdc.com>
This patch creates a helper for handling throttling code in the
null_handle_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/block/null_blk_main.c | 39 ++++++++++++++++++++++-------------
1 file changed, 25 insertions(+), 14 deletions(-)
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 7277f2db8ec9..751679fadc9d 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1133,28 +1133,39 @@ static void null_restart_queue_async(struct nullb *nullb)
blk_mq_start_stopped_hw_queues(q, true);
}
+static inline blk_status_t null_handle_throttled(struct nullb_cmd *cmd)
+{
+ struct nullb_device *dev = cmd->nq->dev;
+ struct nullb *nullb = dev->nullb;
+ blk_status_t sts = BLK_STS_OK;
+ struct request *rq = cmd->rq;
+
+ if (!hrtimer_active(&nullb->bw_timer))
+ hrtimer_restart(&nullb->bw_timer);
+
+ if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) {
+ null_stop_queue(nullb);
+ /* race with timer */
+ if (atomic_long_read(&nullb->cur_bytes) > 0)
+ null_restart_queue_async(nullb);
+ /* requeue request */
+ sts = BLK_STS_DEV_RESOURCE;
+ }
+ return sts;
+}
+
static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector,
sector_t nr_sectors, enum req_opf op)
{
struct nullb_device *dev = cmd->nq->dev;
struct nullb *nullb = dev->nullb;
+ blk_status_t sts;
int err = 0;
if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
- struct request *rq = cmd->rq;
-
- if (!hrtimer_active(&nullb->bw_timer))
- hrtimer_restart(&nullb->bw_timer);
-
- if (atomic_long_sub_return(blk_rq_bytes(rq),
- &nullb->cur_bytes) < 0) {
- null_stop_queue(nullb);
- /* race with timer */
- if (atomic_long_read(&nullb->cur_bytes) > 0)
- null_restart_queue_async(nullb);
- /* requeue request */
- return BLK_STS_DEV_RESOURCE;
- }
+ sts = null_handle_throttled(cmd);
+ if (sts != BLK_STS_OK)
+ return sts;
}
if (op == REQ_OP_FLUSH) {
--
2.17.0
next prev parent reply other threads:[~2019-08-21 6:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 6:13 [PATCH V3 0/6] null_blk: simplify null_handle_cmd() Chaitanya Kulkarni
2019-08-21 6:13 ` [PATCH V3 1/6] null_blk: move duplicate code to callers Chaitanya Kulkarni
2019-08-22 0:55 ` Christoph Hellwig
2019-08-21 6:13 ` Chaitanya Kulkarni [this message]
2019-08-22 0:55 ` [PATCH V3 2/6] null_blk: create a helper for throttling Christoph Hellwig
2019-08-21 6:13 ` [PATCH V3 3/6] null_blk: create a helper for badblocks Chaitanya Kulkarni
2019-08-22 0:55 ` Christoph Hellwig
2019-08-21 6:13 ` [PATCH V3 4/6] null_blk: create a helper for mem-backed ops Chaitanya Kulkarni
2019-08-22 0:56 ` Christoph Hellwig
2019-08-21 6:13 ` [PATCH V3 5/6] null_blk: create a helper for zoned devices Chaitanya Kulkarni
2019-08-22 0:58 ` Christoph Hellwig
2019-08-22 2:23 ` Chaitanya Kulkarni
2019-08-21 6:13 ` [PATCH V3 6/6] null_blk: create a helper for req completion Chaitanya Kulkarni
2019-08-22 0:59 ` Christoph Hellwig
2019-08-22 2:17 ` Chaitanya Kulkarni
2019-08-22 2:23 ` Chaitanya Kulkarni
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