Re: [PATCH 2.6 3/5]: Use double-linked list for dev->qdisc_list

[Patrick McHardy <kaber@xxxxxxxxx>]

David S. Miller wrote:

> On Tue, 03 Aug 2004 17:24:50 +0200
> Patrick McHardy <kaber@xxxxxxxxx> wrote:
>
>  
>
> > This patch changes dev->qdisc_list to a double-linked list. This solves
> > the performance problems when destroying qdiscs with large number of inner
> > qdiscs.
> >    
> I don't see how this bit is correct:
>  
You're right. This patch on top fixes the problem.

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2004/08/04 21:51:04+02:00 kaber@xxxxxxxxxxxx 
#   [PKT_SCHED]: Fix q_idx calculation in tc_dump_qdisc
#   
#   Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
# 
# net/sched/sch_api.c
#   2004/08/04 21:50:44+02:00 kaber@xxxxxxxxxxxx +5 -2
#   [PKT_SCHED]: Fix q_idx calculation in tc_dump_qdisc
# 
diff -Nru a/net/sched/sch_api.c b/net/sched/sch_api.c
--- a/net/sched/sch_api.c       2004-08-04 21:55:13 +02:00
+++ b/net/sched/sch_api.c       2004-08-04 21:55:13 +02:00
@@ -817,13 +817,16 @@
                read_lock_bh(&qdisc_tree_lock);
                q_idx = 0;
                list_for_each_entry(q, &dev->qdisc_list, list) {
-                       if (q_idx++ < s_q_idx)
+                       if (q_idx < s_q_idx) {
+                               q_idx++;
                                continue;
+                       }
                        if (tc_fill_qdisc(skb, q, 0, NETLINK_CB(cb->skb).pid,
                                          cb->nlh->nlmsg_seq, NLM_F_MULTI, 
RTM_NEWQDISC) <= 0) {
                                read_unlock_bh(&qdisc_tree_lock);
                                goto done;
                        }
+                       q_idx++;
                }
                read_unlock_bh(&qdisc_tree_lock);
        }
@@ -832,7 +835,7 @@
        read_unlock(&dev_base_lock);
 
        cb->args[0] = idx;
-       cb->args[1] = q_idx - 1;
+       cb->args[1] = q_idx;
 
        return skb->len;
 }