Re: [patch] block layer: kmemcheck fixes

Linus Torvalds
2008-02-07T17:44:00Z

On Thu, 7 Feb 2008, Ingo Molnar wrote:
> INIT_HLIST_NODE(&rq->hash);
> RB_CLEAR_NODE(&rq->rb_node);
> - rq->ioprio = 0;
> - rq->buffer = NULL;
> - rq->ref_count = 1;
> - rq->q = q;
> - rq->special = NULL;
> - rq->data_len = 0;
> - rq->data = NULL;
> - rq->nr_phys_segments = 0;
> - rq->sense = NULL;
> - rq->end_io = NULL;
> - rq->end_io_data = NULL;
> - rq->completion_data = NULL;
> - rq->next_rq = NULL;
> + rq->completion_data = NULL;
> + /* rq->elevator_private */
> + /* rq->elevator_private2 */
> + /* rq->rq_disk */
> + /* rq->start_time */
> + rq->nr_phys_segments = 0;
> + /* rq->nr_hw_segments */
> + rq->ioprio = 0;
> + rq->special = NULL;
> + rq->buffer = NULL;
...

Can we please just stop doing these one-by-one assignments, and just do
something like

memset(rq, 0, sizeof(*rq));
rq->q = q;
rq->ref_count = 1;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);

instead?

The memset() is likely faster and smaller than one-by-one assignments
anyway, even if the one-by-ones can avoid initializing some field or there
ends up being a double initialization..

Linus