Hi,
On 2019/3/11 21:51, Damien Le Moal wrote:
On 2019/03/11 6:31, yuyufen wrote:
ping?
On 2019/3/1 9:28, Yufen Yu wrote:
For q->poll_nsec == -1, means doing classic poll, not hybrid poll.
We introduce a new flag BLK_MQ_POLL_CLASSIC to replace -1, which
may make code much easier to read.
Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
---
block/blk-mq.c | 4 ++--
block/blk-sysfs.c | 4 ++--
include/linux/blkdev.h | 3 +++
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9437a5eb07cf..e70202e3b378 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2857,7 +2857,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
/*
* Default to classic polling
*/
- q->poll_nsec = -1;
+ q->poll_nsec = BLK_MQ_POLL_CLASSIC;
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
blk_mq_add_queue_tag_set(set, q);
@@ -3389,7 +3389,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
{
struct request *rq;
- if (q->poll_nsec == -1)
+ if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
return false;
if (!blk_qc_t_is_internal(cookie))
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 590d1ef2f961..8639e135687e 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -360,7 +360,7 @@ static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
{
int val;
- if (q->poll_nsec == -1)
+ if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
val = -1;
else
val = q->poll_nsec / 1000;
@@ -381,7 +381,7 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
return err;
if (val == -1)
Since val is an int obtained with kstrtoint(), val can be a negative value other
than -1. So what about something like:
if (val == BLK_MQ_POLL_CLASSIC)
q->poll_nsec = BLK_MQ_POLL_CLASSIC;
else if (val >= 0)
q->poll_nsec = val * 1000;
else
return -EINVAL;
That would avoid problems with negative values other than -1.
I agree with you. This may be more reasonable.
Thanks a lot for your suggestion.
Yufen.
Thanks
- q->poll_nsec = -1;
+ q->poll_nsec = BLK_MQ_POLL_CLASSIC;
else
q->poll_nsec = val * 1000;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 338604dff7d0..f9c2ebf5e621 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -50,6 +50,9 @@ struct blk_stat_callback;
/* Must be consistent with blk_mq_poll_stats_bkt() */
#define BLK_MQ_POLL_STATS_BKTS 16
+/* Doing classic polling */
+#define BLK_MQ_POLL_CLASSIC -1
+
/*
* Maximum number of blkcg policies allowed to be registered concurrently.
* Defined here to simplify include dependency.
