| Message ID | 20170929170951.GA18535@localhost.didichuxing.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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;
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
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)
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(-)