From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
To: linux-block@vger.kernel.org
Cc: hch@lst.de, Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Subject: [PATCH V2 2/6] null_blk: create a helper for throttling
Date: Tue, 9 Jul 2019 12:21:28 -0700 [thread overview]
Message-ID: <20190709192132.24723-3-chaitanya.kulkarni@wdc.com> (raw)
In-Reply-To: <20190709192132.24723-1-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 b3be08edea43..4447c9729827 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:[~2019-07-09 19:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 19:21 [PATCH V2 0/6] null_blk: simplify null_handle_cmd() Chaitanya Kulkarni
2019-07-09 19:21 ` [PATCH V2 1/6] null_blk: move duplicate code to callers Chaitanya Kulkarni
2019-07-09 19:21 ` Chaitanya Kulkarni [this message]
2019-07-09 19:21 ` [PATCH V2 3/6] null_blk: create a helper for badblocks Chaitanya Kulkarni
2019-07-09 19:21 ` [PATCH V2 4/6] null_blk: create a helper for mem-backed ops Chaitanya Kulkarni
2019-07-09 19:21 ` [PATCH V2 5/6] null_blk: create a helper for zoned devices Chaitanya Kulkarni
2019-07-09 19:21 ` [PATCH V2 6/6] null_blk: create a helper for req completion Chaitanya Kulkarni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190709192132.24723-3-chaitanya.kulkarni@wdc.com \
--to=chaitanya.kulkarni@wdc.com \
--cc=hch@lst.de \
--cc=linux-block@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.