Re: [patch] block layer: kmemcheck fixes

Jens Axboe
2008-02-07T17:55:58Z

On Thu, Feb 07 2008, Linus Torvalds wrote:
>
>
> 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..

I completely agree, the fidgeting with single members quickly loses
appeal. Ingo, I'll merge and integrate your fixes before leaving, I'll
be here all day tomorrow as well.

--
Jens Axboe