Commit d2d481d0 authored by Jeff Moyer's avatar Jeff Moyer Committed by Jens Axboe
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cfq-iosched: Expose microsecond interfaces 



Expose interfaces to tune time slices of CFQ IO scheduler in
microseconds.

Signed-off-by: default avatarJeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 9a7f38c4

block/cfq-iosched.c

+40 −0
Original line number Diff line number Diff line
@@ -4690,6 +4690,21 @@ SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); 
SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1);

#undef SHOW_FUNCTION



#define USEC_SHOW_FUNCTION(__FUNC, __VAR)				\

static ssize_t __FUNC(struct elevator_queue *e, char *page)		\

{									\

	struct cfq_data *cfqd = e->elevator_data;			\

	u64 __data = __VAR;						\

	__data = div_u64(__data, NSEC_PER_USEC);			\

	return cfq_var_show(__data, (page));				\

}

USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle);

USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle);

USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]);

USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]);

USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency);

#undef USEC_SHOW_FUNCTION



#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\

static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\

{									\
@@ -4724,6 +4739,26 @@ STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); 
STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1);

#undef STORE_FUNCTION



#define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX)			\

static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\

{									\

	struct cfq_data *cfqd = e->elevator_data;			\

	unsigned int __data;						\

	int ret = cfq_var_store(&__data, (page), count);		\

	if (__data < (MIN))						\

		__data = (MIN);						\

	else if (__data > (MAX))					\

		__data = (MAX);						\

	*(__PTR) = (u64)__data * NSEC_PER_USEC;				\

	return ret;							\

}

USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX);

USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX);

USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX);

USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX);

USEC_STORE_FUNCTION(cfq_target_latency_us_store, &cfqd->cfq_target_latency, 1, UINT_MAX);

#undef USEC_STORE_FUNCTION



#define CFQ_ATTR(name) \

	__ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store)
@@ -4734,12 +4769,17 @@ static struct elv_fs_entry cfq_attrs[] = { 
	CFQ_ATTR(back_seek_max),

	CFQ_ATTR(back_seek_penalty),

	CFQ_ATTR(slice_sync),

	CFQ_ATTR(slice_sync_us),

	CFQ_ATTR(slice_async),

	CFQ_ATTR(slice_async_us),

	CFQ_ATTR(slice_async_rq),

	CFQ_ATTR(slice_idle),

	CFQ_ATTR(slice_idle_us),

	CFQ_ATTR(group_idle),

	CFQ_ATTR(group_idle_us),

	CFQ_ATTR(low_latency),

	CFQ_ATTR(target_latency),

	CFQ_ATTR(target_latency_us),

	__ATTR_NULL

};