Subject: Re: [PATCH] RDS: Simplify code

From: Leon Romanovsky <[email-masked]>
Date: Sun, 4 Sep 2016 21:23:54 +0300

On Sun, Sep 04, 2016 at 05:57:20PM +0200, Christophe JAILLET wrote:
> Le 04/09/2016 à 14:20, Leon Romanovsky a écrit :
> >On Sat, Sep 03, 2016 at 07:33:29AM +0200, Christophe JAILLET wrote:
> >>Calling 'list_splice' followed by 'INIT_LIST_HEAD' is equivalent to
> >>'list_splice_init'.
> >It is not 100% accurate
> >
> >list_splice(y, z)
> >INIT_LIST_HEAD(y)
> >
> >==>
> >
> >if (!list_empty(y))
> >      __list_splice(y, z, z>next);
> >INIT_LIST_HEAD(y)
> >
> >and not
> >
> >if (!list_empty(y)) {
> >      __list_splice(y, z, z>next);
> >      INIT_LIST_HEAD(y)
> >}
> >
> >as list_splice_init will do.
> >
> You are right but if you dig further you will see that calling
> INIT_LIST_HEAD on an empty list is a no-op (AFAIK).
> And if this list was not already correctly initialized, then you would have
> some other troubles.

Thank you for the suggestion,
It looks like the code after that can be skipped in case of loop_conns
list is empty, the tmp_list will be empty too.

174         list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {
175                 WARN_ON(lc->conn->c_passive);
176                 rds_conn_destroy(lc->conn);
177         }

> CJ