From 0f9af6dcd9fc3d752a546dbd20a9b3cd6a94a4eb Mon Sep 17 00:00:00 2001 From: Christian Marangi Date: Tue, 29 Apr 2025 18:55:19 +0200 Subject: [PATCH] generic: drop extra-old-deprecated pending fix patch for sch codel Patch 620-net_sched-codel-do-not-defer-queue-length-update.patch is actually an ancient patch that somehow manage to be ported for 7 solid years. This comes from [1] where a fix patch was proposed. Nobody notice that the proposed patch was actually rejected upstream in favor of [2]. And the upstream fix patch is present in kernel from version 4.18. This means that we were actually fixing for a non existant bug and maybe introducing regression down the line. Drop the patch for good as we already have a fix for it in flace for a long time. [1] https://bugzilla.kernel.org/show_bug.cgi?id=109581 [2] https://github.com/torvalds/linux/commit/35b42da69e35536da603a50e40aa6c41b2f7b0f8 Signed-off-by: Christian Marangi --- ...del-do-not-defer-queue-length-update.patch | 86 ------------------- 1 file changed, 86 deletions(-) delete mode 100644 target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch diff --git a/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch b/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch deleted file mode 100644 index 4b4825ae3b9..00000000000 --- a/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch +++ /dev/null @@ -1,86 +0,0 @@ -From: Konstantin Khlebnikov -Date: Mon, 21 Aug 2017 11:14:14 +0300 -Subject: [PATCH] net_sched/codel: do not defer queue length update - -When codel wants to drop last packet in ->dequeue() it cannot call -qdisc_tree_reduce_backlog() right away - it will notify parent qdisc -about zero qlen and HTB/HFSC will deactivate class. The same class will -be deactivated second time by caller of ->dequeue(). Currently codel and -fq_codel defer update. This triggers warning in HFSC when it's qlen != 0 -but there is no active classes. - -This patch update parent queue length immediately: just temporary increase -qlen around qdisc_tree_reduce_backlog() to prevent first class deactivation -if we have skb to return. - -This might open another problem in HFSC - now operation peek could fail and -deactivate parent class. - -Signed-off-by: Konstantin Khlebnikov -Link: https://bugzilla.kernel.org/show_bug.cgi?id=109581 ---- - ---- a/net/sched/sch_codel.c -+++ b/net/sched/sch_codel.c -@@ -95,11 +95,17 @@ static struct sk_buff *codel_qdisc_deque - &q->stats, qdisc_pkt_len, codel_get_enqueue_time, - drop_func, dequeue_func); - -- /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, -- * or HTB crashes. Defer it for next round. -+ /* If our qlen is 0 qdisc_tree_reduce_backlog() will deactivate -+ * parent class, dequeue in parent qdisc will do the same if we -+ * return skb. Temporary increment qlen if we have skb. - */ -- if (q->stats.drop_count && sch->q.qlen) { -- qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len); -+ if (q->stats.drop_count) { -+ if (skb) -+ sch->q.qlen++; -+ qdisc_tree_reduce_backlog(sch, q->stats.drop_count, -+ q->stats.drop_len); -+ if (skb) -+ sch->q.qlen--; - q->stats.drop_count = 0; - q->stats.drop_len = 0; - } ---- a/net/sched/sch_fq_codel.c -+++ b/net/sched/sch_fq_codel.c -@@ -304,6 +304,21 @@ begin: - &flow->cvars, &q->cstats, qdisc_pkt_len, - codel_get_enqueue_time, drop_func, dequeue_func); - -+ /* If our qlen is 0 qdisc_tree_reduce_backlog() will deactivate -+ * parent class, dequeue in parent qdisc will do the same if we -+ * return skb. Temporary increment qlen if we have skb. -+ */ -+ if (q->cstats.drop_count) { -+ if (skb) -+ sch->q.qlen++; -+ qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, -+ q->cstats.drop_len); -+ if (skb) -+ sch->q.qlen--; -+ q->cstats.drop_count = 0; -+ q->cstats.drop_len = 0; -+ } -+ - if (!skb) { - /* force a pass through old_flows to prevent starvation */ - if ((head == &q->new_flows) && !list_empty(&q->old_flows)) -@@ -314,15 +329,6 @@ begin: - } - qdisc_bstats_update(sch, skb); - flow->deficit -= qdisc_pkt_len(skb); -- /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, -- * or HTB crashes. Defer it for next round. -- */ -- if (q->cstats.drop_count && sch->q.qlen) { -- qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, -- q->cstats.drop_len); -- q->cstats.drop_count = 0; -- q->cstats.drop_len = 0; -- } - return skb; - } -