[dm-devel] Re: [PATCH 02/24] io-controller: Core of the elevator fair queuing

[Gui Jianfeng <guijianfeng cn fujitsu com>]

Vivek Goyal wrote:
...
> +static void update_min_vdisktime(struct io_service_tree *st)
> +{
> +	u64 vdisktime;
> +
> +	if (st->active_entity)
> +		vdisktime = st->active_entity->vdisktime;
> +
> +	if (st->rb_leftmost) {
> +		struct io_entity *entity = rb_entry(st->rb_leftmost,
> +						struct io_entity, rb_node);
> +
> +		if (!st->active_entity)
> +			vdisktime = entity->vdisktime;
> +		else
> +			vdisktime = min_vdisktime(vdisktime, entity->vdisktime);
> +	}
> +
> +	st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime);
> +}

block/elevator-fq.c: In function ‘elv_ioq_slice_expired’:
block/elevator-fq.c:132: warning: ‘vdisktime’ may be used uninitialized in this function
LD      block/built-in.o

We'd better initialize vdisktime at first.

Signed-off-by: Gui Jianfeng <guijianfeng cn fujitsu com>
---
 block/elevator-fq.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/block/elevator-fq.c b/block/elevator-fq.c
index d04e925..a4161c2 100644
--- a/block/elevator-fq.c
+++ b/block/elevator-fq.c
@@ -131,6 +131,8 @@ static void update_min_vdisktime(struct io_service_tree *st)
 {
 	u64 vdisktime;
 
+	vdisktime = st->min_vdisktime;
+
 	if (st->active_entity)
 		vdisktime = st->active_entity->vdisktime;
 
-- 
1.5.4.rc3