[openwrt/openwrt] kernel: merge a pending fix for HFSC warnings/slowdowns (fixes FS#1136)
LEDE Commits
lede-commits at lists.infradead.org
Sun Mar 11 00:29:03 PST 2018
nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/9306bdf31c0b536389f79d66cee3dcc2d97735c1
commit 9306bdf31c0b536389f79d66cee3dcc2d97735c1
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Sat Mar 10 10:09:07 2018 +0100
kernel: merge a pending fix for HFSC warnings/slowdowns (fixes FS#1136)
Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
.../generic/hack-4.14/660-fq_codel_defaults.patch | 2 +-
.../hack-4.14/661-use_fq_codel_by_default.patch | 4 +-
.../generic/hack-4.9/660-fq_codel_defaults.patch | 2 +-
.../hack-4.9/661-use_fq_codel_by_default.patch | 4 +-
...ed-codel-do-not-defer-queue-length-update.patch | 86 ++++++++++++++++++++++
...ed-codel-do-not-defer-queue-length-update.patch | 86 ++++++++++++++++++++++
.../pending-4.4/660-fq_codel_defaults.patch | 2 +-
.../pending-4.4/662-use_fq_codel_by_default.patch | 4 +-
...ed-codel-do-not-defer-queue-length-update.patch | 86 ++++++++++++++++++++++
9 files changed, 267 insertions(+), 9 deletions(-)
diff --git a/target/linux/generic/hack-4.14/660-fq_codel_defaults.patch b/target/linux/generic/hack-4.14/660-fq_codel_defaults.patch
index 3e27351..b923a2d 100644
--- a/target/linux/generic/hack-4.14/660-fq_codel_defaults.patch
+++ b/target/linux/generic/hack-4.14/660-fq_codel_defaults.patch
@@ -13,7 +13,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -465,7 +465,11 @@ static int fq_codel_init(struct Qdisc *s
+@@ -471,7 +471,11 @@ static int fq_codel_init(struct Qdisc *s
sch->limit = 10*1024;
q->flows_cnt = 1024;
diff --git a/target/linux/generic/hack-4.14/661-use_fq_codel_by_default.patch b/target/linux/generic/hack-4.14/661-use_fq_codel_by_default.patch
index e1eee00..5b61d74 100644
--- a/target/linux/generic/hack-4.14/661-use_fq_codel_by_default.patch
+++ b/target/linux/generic/hack-4.14/661-use_fq_codel_by_default.patch
@@ -55,7 +55,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
register_qdisc(&pfifo_head_drop_qdisc_ops);
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -694,7 +694,7 @@ static const struct Qdisc_class_ops fq_c
+@@ -700,7 +700,7 @@ static const struct Qdisc_class_ops fq_c
.walk = fq_codel_walk,
};
@@ -64,7 +64,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
.cl_ops = &fq_codel_class_ops,
.id = "fq_codel",
.priv_size = sizeof(struct fq_codel_sched_data),
-@@ -709,6 +709,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
+@@ -715,6 +715,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
.dump_stats = fq_codel_dump_stats,
.owner = THIS_MODULE,
};
diff --git a/target/linux/generic/hack-4.9/660-fq_codel_defaults.patch b/target/linux/generic/hack-4.9/660-fq_codel_defaults.patch
index 3e64730..ea461e1 100644
--- a/target/linux/generic/hack-4.9/660-fq_codel_defaults.patch
+++ b/target/linux/generic/hack-4.9/660-fq_codel_defaults.patch
@@ -13,7 +13,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -479,7 +479,11 @@ static int fq_codel_init(struct Qdisc *s
+@@ -485,7 +485,11 @@ static int fq_codel_init(struct Qdisc *s
sch->limit = 10*1024;
q->flows_cnt = 1024;
diff --git a/target/linux/generic/hack-4.9/661-use_fq_codel_by_default.patch b/target/linux/generic/hack-4.9/661-use_fq_codel_by_default.patch
index 7a249e3..981170c 100644
--- a/target/linux/generic/hack-4.9/661-use_fq_codel_by_default.patch
+++ b/target/linux/generic/hack-4.9/661-use_fq_codel_by_default.patch
@@ -55,7 +55,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
register_qdisc(&pfifo_head_drop_qdisc_ops);
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -709,7 +709,7 @@ static const struct Qdisc_class_ops fq_c
+@@ -715,7 +715,7 @@ static const struct Qdisc_class_ops fq_c
.walk = fq_codel_walk,
};
@@ -64,7 +64,7 @@ Signed-off-by: Felix Fietkau <nbd at nbd.name>
.cl_ops = &fq_codel_class_ops,
.id = "fq_codel",
.priv_size = sizeof(struct fq_codel_sched_data),
-@@ -724,6 +724,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
+@@ -730,6 +730,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
.dump_stats = fq_codel_dump_stats,
.owner = THIS_MODULE,
};
diff --git a/target/linux/generic/pending-4.14/620-net_sched-codel-do-not-defer-queue-length-update.patch b/target/linux/generic/pending-4.14/620-net_sched-codel-do-not-defer-queue-length-update.patch
new file mode 100644
index 0000000..b3c35ee
--- /dev/null
+++ b/target/linux/generic/pending-4.14/620-net_sched-codel-do-not-defer-queue-length-update.patch
@@ -0,0 +1,86 @@
+From: Konstantin Khlebnikov <khlebnikov at yandex-team.ru>
+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 <khlebnikov at yandex-team.ru>
+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
+@@ -316,6 +316,21 @@ begin:
+ flow->dropped += q->cstats.drop_count - prev_drop_count;
+ flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
+
++ /* 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))
+@@ -326,15 +341,6 @@ 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;
+ }
+
diff --git a/target/linux/generic/pending-4.4/620-net_sched-codel-do-not-defer-queue-length-update.patch b/target/linux/generic/pending-4.4/620-net_sched-codel-do-not-defer-queue-length-update.patch
new file mode 100644
index 0000000..2ec9c7a
--- /dev/null
+++ b/target/linux/generic/pending-4.4/620-net_sched-codel-do-not-defer-queue-length-update.patch
@@ -0,0 +1,86 @@
+From: Konstantin Khlebnikov <khlebnikov at yandex-team.ru>
+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 <khlebnikov at yandex-team.ru>
+Link: https://bugzilla.kernel.org/show_bug.cgi?id=109581
+---
+
+--- a/net/sched/sch_codel.c
++++ b/net/sched/sch_codel.c
+@@ -79,11 +79,17 @@ static struct sk_buff *codel_qdisc_deque
+
+ skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats, dequeue);
+
+- /* 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
+@@ -311,6 +311,21 @@ begin:
+ flow->dropped += q->cstats.drop_count - prev_drop_count;
+ flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
+
++ /* 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))
+@@ -321,15 +336,6 @@ 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;
+ }
+
diff --git a/target/linux/generic/pending-4.4/660-fq_codel_defaults.patch b/target/linux/generic/pending-4.4/660-fq_codel_defaults.patch
index 46fceff..fbe9008 100644
--- a/target/linux/generic/pending-4.4/660-fq_codel_defaults.patch
+++ b/target/linux/generic/pending-4.4/660-fq_codel_defaults.patch
@@ -1,6 +1,6 @@
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -471,7 +471,7 @@ static int fq_codel_init(struct Qdisc *s
+@@ -477,7 +477,7 @@ static int fq_codel_init(struct Qdisc *s
sch->limit = 10*1024;
q->flows_cnt = 1024;
diff --git a/target/linux/generic/pending-4.4/662-use_fq_codel_by_default.patch b/target/linux/generic/pending-4.4/662-use_fq_codel_by_default.patch
index 9d1962c..8d70b82 100644
--- a/target/linux/generic/pending-4.4/662-use_fq_codel_by_default.patch
+++ b/target/linux/generic/pending-4.4/662-use_fq_codel_by_default.patch
@@ -13,7 +13,7 @@
device, it has to decide which ones to send first, which ones to
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
-@@ -688,7 +688,7 @@ static const struct Qdisc_class_ops fq_c
+@@ -694,7 +694,7 @@ static const struct Qdisc_class_ops fq_c
.walk = fq_codel_walk,
};
@@ -22,7 +22,7 @@
.cl_ops = &fq_codel_class_ops,
.id = "fq_codel",
.priv_size = sizeof(struct fq_codel_sched_data),
-@@ -704,6 +704,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
+@@ -710,6 +710,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
.dump_stats = fq_codel_dump_stats,
.owner = THIS_MODULE,
};
diff --git a/target/linux/generic/pending-4.9/620-net_sched-codel-do-not-defer-queue-length-update.patch b/target/linux/generic/pending-4.9/620-net_sched-codel-do-not-defer-queue-length-update.patch
new file mode 100644
index 0000000..6fe863a
--- /dev/null
+++ b/target/linux/generic/pending-4.9/620-net_sched-codel-do-not-defer-queue-length-update.patch
@@ -0,0 +1,86 @@
+From: Konstantin Khlebnikov <khlebnikov at yandex-team.ru>
+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 <khlebnikov at yandex-team.ru>
+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
+@@ -318,6 +318,21 @@ begin:
+ flow->dropped += q->cstats.drop_count - prev_drop_count;
+ flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
+
++ /* 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))
+@@ -328,15 +343,6 @@ 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;
+ }
+
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