Commit b94c8afc authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller

pkt_sched: remove unnecessary xchg() in packet schedulers

The use of xchg() hasn't been necessary since 2.2.something when proper
locking was added to packet schedulers.
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c19d0369
......@@ -102,7 +102,8 @@ static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
return -EINVAL;
if (!new)
new = &noop_qdisc;
*old = xchg(&flow->q, new);
*old = flow->q;
flow->q = new;
if (*old)
qdisc_reset(*old);
return 0;
......
......@@ -1635,7 +1635,8 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
#endif
}
sch_tree_lock(sch);
*old = xchg(&cl->q, new);
*old = cl->q;
cl->q = new;
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
sch_tree_unlock(sch);
......@@ -1776,8 +1777,8 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
cbq_deactivate_class(cl);
if (rtab) {
rtab = xchg(&cl->R_tab, rtab);
qdisc_put_rtab(rtab);
qdisc_put_rtab(cl->R_tab);
cl->R_tab = rtab;
}
if (tb[TCA_CBQ_LSSOPT])
......
......@@ -208,7 +208,8 @@ static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
sch_tree_lock(sch);
drr_purge_queue(cl);
*old = xchg(&cl->qdisc, new);
*old = cl->qdisc;
cl->qdisc = new;
sch_tree_unlock(sch);
return 0;
}
......
......@@ -68,7 +68,8 @@ static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
}
sch_tree_lock(sch);
*old = xchg(&p->q, new);
*old = p->q;
p->q = new;
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
sch_tree_unlock(sch);
......
......@@ -1202,7 +1202,8 @@ hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
sch_tree_lock(sch);
hfsc_purge_queue(sch, cl);
*old = xchg(&cl->qdisc, new);
*old = cl->qdisc;
cl->qdisc = new;
sch_tree_unlock(sch);
return 0;
}
......
......@@ -1100,7 +1100,9 @@ static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
== NULL)
return -ENOBUFS;
sch_tree_lock(sch);
if ((*old = xchg(&cl->un.leaf.q, new)) != NULL) {
*old = cl->un.leaf.q;
cl->un.leaf.q = new;
if (*old != NULL) {
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
}
......
......@@ -214,7 +214,8 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
q->bands = qopt->bands;
for (i = q->bands; i < q->max_bands; i++) {
if (q->queues[i] != &noop_qdisc) {
struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
struct Qdisc *child = q->queues[i];
q->queues[i] = &noop_qdisc;
qdisc_tree_decrease_qlen(child, child->q.qlen);
qdisc_destroy(child);
}
......@@ -224,7 +225,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
for (i = 0; i < q->bands; i++) {
if (q->queues[i] == &noop_qdisc) {
struct Qdisc *child;
struct Qdisc *child, *old;
child = qdisc_create_dflt(qdisc_dev(sch),
sch->dev_queue,
&pfifo_qdisc_ops,
......@@ -232,12 +233,13 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
i + 1));
if (child) {
sch_tree_lock(sch);
child = xchg(&q->queues[i], child);
old = q->queues[i];
q->queues[i] = child;
if (child != &noop_qdisc) {
qdisc_tree_decrease_qlen(child,
child->q.qlen);
qdisc_destroy(child);
if (old != &noop_qdisc) {
qdisc_tree_decrease_qlen(old,
old->q.qlen);
qdisc_destroy(old);
}
sch_tree_unlock(sch);
}
......
......@@ -331,10 +331,9 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
root_lock = qdisc_root_sleeping_lock(sch);
spin_lock_bh(root_lock);
d = xchg(&q->delay_dist, d);
kfree(q->delay_dist);
q->delay_dist = d;
spin_unlock_bh(root_lock);
kfree(d);
return 0;
}
......
......@@ -187,7 +187,8 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
struct Qdisc *child = q->queues[i];
q->queues[i] = &noop_qdisc;
if (child != &noop_qdisc) {
qdisc_tree_decrease_qlen(child, child->q.qlen);
qdisc_destroy(child);
......@@ -197,18 +198,19 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
for (i=0; i<q->bands; i++) {
if (q->queues[i] == &noop_qdisc) {
struct Qdisc *child;
struct Qdisc *child, *old;
child = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
&pfifo_qdisc_ops,
TC_H_MAKE(sch->handle, i + 1));
if (child) {
sch_tree_lock(sch);
child = xchg(&q->queues[i], child);
old = q->queues[i];
q->queues[i] = child;
if (child != &noop_qdisc) {
qdisc_tree_decrease_qlen(child,
child->q.qlen);
qdisc_destroy(child);
if (old != &noop_qdisc) {
qdisc_tree_decrease_qlen(old,
old->q.qlen);
qdisc_destroy(old);
}
sch_tree_unlock(sch);
}
......
......@@ -202,7 +202,8 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt)
q->limit = ctl->limit;
if (child) {
qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
qdisc_destroy(xchg(&q->qdisc, child));
qdisc_destroy(q->qdisc);
q->qdisc = child;
}
red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
......@@ -283,7 +284,8 @@ static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
new = &noop_qdisc;
sch_tree_lock(sch);
*old = xchg(&q->qdisc, new);
*old = q->qdisc;
q->qdisc = new;
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
sch_tree_unlock(sch);
......
......@@ -236,6 +236,7 @@ static int tbf_change(struct Qdisc* sch, struct nlattr *opt)
struct tc_tbf_qopt *qopt;
struct qdisc_rate_table *rtab = NULL;
struct qdisc_rate_table *ptab = NULL;
struct qdisc_rate_table *tmp;
struct Qdisc *child = NULL;
int max_size,n;
......@@ -284,7 +285,8 @@ static int tbf_change(struct Qdisc* sch, struct nlattr *opt)
sch_tree_lock(sch);
if (child) {
qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
qdisc_destroy(xchg(&q->qdisc, child));
qdisc_destroy(q->qdisc);
q->qdisc = child;
}
q->limit = qopt->limit;
q->mtu = qopt->mtu;
......@@ -292,8 +294,14 @@ static int tbf_change(struct Qdisc* sch, struct nlattr *opt)
q->buffer = qopt->buffer;
q->tokens = q->buffer;
q->ptokens = q->mtu;
rtab = xchg(&q->R_tab, rtab);
ptab = xchg(&q->P_tab, ptab);
tmp = q->R_tab;
q->R_tab = rtab;
rtab = tmp;
tmp = q->P_tab;
q->P_tab = ptab;
ptab = tmp;
sch_tree_unlock(sch);
err = 0;
done:
......@@ -383,7 +391,8 @@ static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
new = &noop_qdisc;
sch_tree_lock(sch);
*old = xchg(&q->qdisc, new);
*old = q->qdisc;
q->qdisc = new;
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
sch_tree_unlock(sch);
......
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