This is a note to let you know that I've just added the patch titled
net_sched: sch_fq: properly set sk->sk_pacing_status
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net_sched-sch_fq-properly-set-sk-sk_pacing_status.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed 01 Jan 2020 10:35:31 PM CET
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Mon, 23 Dec 2019 11:13:24 -0800
Subject: net_sched: sch_fq: properly set sk->sk_pacing_status
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit bb3d0b8bf5be61ab1d6f472c43cbf34de17e796b ]
If fq_classify() recycles a struct fq_flow because
a socket structure has been reallocated, we do not
set sk->sk_pacing_status immediately, but later if the
flow becomes detached.
This means that any flow requiring pacing (BBR, or SO_MAX_PACING_RATE)
might fallback to TCP internal pacing, which requires a per-socket
high resolution timer, and therefore more cpu cycles.
Fixes: 218af599fa63 ("tcp: internal implementation for pacing")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Cc: Neal Cardwell <ncardwell@xxxxxxxxxx>
Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/sch_fq.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -301,6 +301,9 @@ static struct fq_flow *fq_classify(struc
f->socket_hash != sk->sk_hash)) {
f->credit = q->initial_quantum;
f->socket_hash = sk->sk_hash;
+ if (q->rate_enable)
+ smp_store_release(&sk->sk_pacing_status,
+ SK_PACING_FQ);
if (fq_flow_is_throttled(f))
fq_flow_unset_throttled(q, f);
f->time_next_packet = 0ULL;
@@ -322,8 +325,12 @@ static struct fq_flow *fq_classify(struc
fq_flow_set_detached(f);
f->sk = sk;
- if (skb->sk == sk)
+ if (skb->sk == sk) {
f->socket_hash = sk->sk_hash;
+ if (q->rate_enable)
+ smp_store_release(&sk->sk_pacing_status,
+ SK_PACING_FQ);
+ }
f->credit = q->initial_quantum;
rb_link_node(&f->fq_node, parent, p);
@@ -428,17 +435,9 @@ static int fq_enqueue(struct sk_buff *sk
f->qlen++;
qdisc_qstats_backlog_inc(sch, skb);
if (fq_flow_is_detached(f)) {
- struct sock *sk = skb->sk;
-
fq_flow_add_tail(&q->new_flows, f);
if (time_after(jiffies, f->age + q->flow_refill_delay))
f->credit = max_t(u32, f->credit, q->quantum);
- if (sk && q->rate_enable) {
- if (unlikely(smp_load_acquire(&sk->sk_pacing_status) !=
- SK_PACING_FQ))
- smp_store_release(&sk->sk_pacing_status,
- SK_PACING_FQ);
- }
q->inactive_flows--;
}
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-5.4/net_sched-sch_fq-properly-set-sk-sk_pacing_status.patch
queue-5.4/net-icmp-fix-data-race-in-cmp_global_allow.patch
queue-5.4/dma-debug-add-a-schedule-point-in-debug_dma_dump_map.patch
queue-5.4/tcp-dccp-fix-possible-race-__inet_lookup_established.patch
queue-5.4/net-add-a-read_once-in-skb_peek_tail.patch
queue-5.4/inetpeer-fix-data-race-in-inet_putpeer-inet_putpeer.patch
queue-5.4/tcp-do-not-send-empty-skb-from-tcp_write_xmit.patch
queue-5.4/netfilter-bridge-make-sure-to-pull-arp-header-in-br_nf_forward_arp.patch
queue-5.4/6pack-mkiss-fix-possible-deadlock.patch
queue-5.4/tcp-fix-highest_sack-and-highest_sack_seq.patch
queue-5.4/hrtimer-annotate-lockless-access-to-timer-state.patch
