* [PATCH] null_blk: add "no_sched" module parameter
@ 2017-09-29 17:09 weiping zhang
2017-09-29 21:39 ` Jens Axboe
0 siblings, 1 reply; 3+ messages in thread
From: weiping zhang @ 2017-09-29 17:09 UTC (permalink / raw)
To: axboe; +Cc: linux-block
add an option that disable io scheduler for null block device.
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
---
drivers/block/null_blk.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index bd92286..3c63863 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -154,6 +154,10 @@ enum {
NULL_Q_MQ = 2,
};
+static int g_no_sched;
+module_param_named(no_sched, g_no_sched, int, S_IRUGO);
+MODULE_PARM_DESC(no_sched, "No io scheduler");
+
static int g_submit_queues = 1;
module_param_named(submit_queues, g_submit_queues, int, S_IRUGO);
MODULE_PARM_DESC(submit_queues, "Number of submission queues");
@@ -1753,7 +1757,7 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
g_hw_queue_depth;
set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
set->cmd_size = sizeof(struct nullb_cmd);
- set->flags = BLK_MQ_F_SHOULD_MERGE;
+ set->flags = g_no_sched ? BLK_MQ_F_NO_SCHED : BLK_MQ_F_SHOULD_MERGE;
set->driver_data = NULL;
if ((nullb && nullb->dev->blocking) || g_blocking)
--
2.9.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] null_blk: add "no_sched" module parameter
2017-09-29 17:09 [PATCH] null_blk: add "no_sched" module parameter weiping zhang
@ 2017-09-29 21:39 ` Jens Axboe
2017-09-30 1:40 ` weiping zhang
0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2017-09-29 21:39 UTC (permalink / raw)
To: weiping zhang; +Cc: linux-block
On 09/29/2017 07:09 PM, weiping zhang wrote:
> add an option that disable io scheduler for null block device.
>
> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
> ---
> drivers/block/null_blk.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
> index bd92286..3c63863 100644
> --- a/drivers/block/null_blk.c
> +++ b/drivers/block/null_blk.c
> @@ -154,6 +154,10 @@ enum {
> NULL_Q_MQ = 2,
> };
>
> +static int g_no_sched;
> +module_param_named(no_sched, g_no_sched, int, S_IRUGO);
> +MODULE_PARM_DESC(no_sched, "No io scheduler");
> +
> static int g_submit_queues = 1;
> module_param_named(submit_queues, g_submit_queues, int, S_IRUGO);
> MODULE_PARM_DESC(submit_queues, "Number of submission queues");
> @@ -1753,7 +1757,7 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
> g_hw_queue_depth;
> set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
> set->cmd_size = sizeof(struct nullb_cmd);
> - set->flags = BLK_MQ_F_SHOULD_MERGE;
> + set->flags = g_no_sched ? BLK_MQ_F_NO_SCHED : BLK_MQ_F_SHOULD_MERGE;
This should be:
set->flags = BLK_MQ_F_SHOULD_MERGE;
if (g_no_sched)
set->flags |= BLK_MQ_F_NO_SCHED;
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] null_blk: add "no_sched" module parameter
2017-09-29 21:39 ` Jens Axboe
@ 2017-09-30 1:40 ` weiping zhang
0 siblings, 0 replies; 3+ messages in thread
From: weiping zhang @ 2017-09-30 1:40 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-block
On Fri, Sep 29, 2017 at 11:39:03PM +0200, Jens Axboe wrote:
> On 09/29/2017 07:09 PM, weiping zhang wrote:
> > add an option that disable io scheduler for null block device.
> >
> > Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
> > ---
> > drivers/block/null_blk.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
> > index bd92286..3c63863 100644
> > --- a/drivers/block/null_blk.c
> > +++ b/drivers/block/null_blk.c
> > @@ -154,6 +154,10 @@ enum {
> > NULL_Q_MQ = 2,
> > };
> >
> > +static int g_no_sched;
> > +module_param_named(no_sched, g_no_sched, int, S_IRUGO);
> > +MODULE_PARM_DESC(no_sched, "No io scheduler");
> > +
> > static int g_submit_queues = 1;
> > module_param_named(submit_queues, g_submit_queues, int, S_IRUGO);
> > MODULE_PARM_DESC(submit_queues, "Number of submission queues");
> > @@ -1753,7 +1757,7 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
> > g_hw_queue_depth;
> > set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
> > set->cmd_size = sizeof(struct nullb_cmd);
> > - set->flags = BLK_MQ_F_SHOULD_MERGE;
> > + set->flags = g_no_sched ? BLK_MQ_F_NO_SCHED : BLK_MQ_F_SHOULD_MERGE;
>
> This should be:
>
> set->flags = BLK_MQ_F_SHOULD_MERGE;
> if (g_no_sched)
> set->flags |= BLK_MQ_F_NO_SCHED;
>
That's right, I go through these two flags, if no io scheduler,
BLK_MQ_F_SHOULD_MERGE can make sw ctx merge happen. I will send V2.
Thanks
weiping
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-09-29 17:09 [PATCH] null_blk: add "no_sched" module parameter weiping zhang
2017-09-29 21:39 ` Jens Axboe
2017-09-30 1:40 ` weiping zhang
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