From: Cong Wang <xiyou.wangcong@gmail.com>
To: Josh Hunt <johunt@akamai.com>
Cc: jonas.bonn@netrounds.com, Paolo Abeni <pabeni@redhat.com>,
Michael Zhivich <mzhivich@akamai.com>,
David Miller <davem@davemloft.net>,
John Fastabend <john.fastabend@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux Kernel Network Developers <netdev@vger.kernel.org>
Subject: Re: Packet gets stuck in NOLOCK pfifo_fast qdisc
Date: Wed, 1 Jul 2020 12:58:45 -0700 [thread overview]
Message-ID: <CAM_iQpWjQiG-zVs+e-V=8LvTFbRwgC4y4eoGERjezfAT0Fmm8g@mail.gmail.com> (raw)
In-Reply-To: <CAM_iQpX1+dHB0kJF8gRfuDeAb9TsA9mB9H_Og8n8Hr19+EMLJA@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 379 bytes --]
On Wed, Jul 1, 2020 at 9:05 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> On Tue, Jun 30, 2020 at 2:08 PM Josh Hunt <johunt@akamai.com> wrote:
> > Do either of you know if there's been any development on a fix for this
> > issue? If not we can propose something.
>
> If you have a reproducer, I can look into this.
Does the attached patch fix this bug completely?
Thanks.
[-- Attachment #2: qdisc_run.diff --]
[-- Type: text/x-patch, Size: 1202 bytes --]
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 9092e697059e..5a03cded3054 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -123,7 +123,7 @@ bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
void __qdisc_run(struct Qdisc *q);
-static inline void qdisc_run(struct Qdisc *q)
+static inline bool qdisc_run(struct Qdisc *q)
{
if (qdisc_run_begin(q)) {
/* NOLOCK qdisc must check 'state' under the qdisc seqlock
@@ -133,7 +133,9 @@ static inline void qdisc_run(struct Qdisc *q)
likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
__qdisc_run(q);
qdisc_run_end(q);
+ return true;
}
+ return false;
}
static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
diff --git a/net/core/dev.c b/net/core/dev.c
index 90b59fc50dc9..c7e48356132a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3744,7 +3744,8 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
if (q->flags & TCQ_F_NOLOCK) {
rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
- qdisc_run(q);
+ if (!qdisc_run(q) && rc == NET_XMIT_SUCCESS)
+ __netif_schedule(q);
if (unlikely(to_free))
kfree_skb_list(to_free);
next prev parent reply other threads:[~2020-07-01 19:59 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-09 6:46 Packet gets stuck in NOLOCK pfifo_fast qdisc Jonas Bonn
2019-10-09 19:14 ` Paolo Abeni
2019-10-10 6:27 ` Jonas Bonn
2019-10-11 0:39 ` Jonas Bonn
2020-06-23 13:42 ` Michael Zhivich
2020-06-30 19:14 ` Josh Hunt
2020-07-01 7:53 ` Jonas Bonn
2020-07-01 16:05 ` Cong Wang
2020-07-01 19:58 ` Cong Wang [this message]
2020-07-01 22:02 ` Josh Hunt
2020-07-02 6:14 ` Jonas Bonn
2020-07-02 9:45 ` Paolo Abeni
2020-07-02 18:08 ` Josh Hunt
2020-07-07 14:18 ` Paolo Abeni
2020-07-08 20:16 ` Cong Wang
2020-07-09 9:20 ` Paolo Abeni
2020-07-08 20:33 ` Zhivich, Michael
2020-08-20 7:43 ` Jike Song
2020-08-20 18:13 ` Josh Hunt
[not found] ` <20200822032800.16296-1-hdanton@sina.com>
2020-08-25 2:18 ` Fengkehuan Feng
[not found] ` <20200825032312.11776-1-hdanton@sina.com>
2020-08-25 7:14 ` Fengkehuan Feng
[not found] ` <20200825162329.11292-1-hdanton@sina.com>
2020-08-26 2:38 ` Kehuan Feng
[not found] ` <CACS=qqKptAQQGiMoCs1Zgs9S4ZppHhasy1AK4df2NxnCDR+vCw@mail.gmail.com>
[not found] ` <5f46032e.1c69fb81.9880c.7a6cSMTPIN_ADDED_MISSING@mx.google.com>
2020-08-27 6:56 ` Kehuan Feng
[not found] ` <20200827125747.5816-1-hdanton@sina.com>
2020-08-28 1:45 ` Kehuan Feng
2020-09-03 5:01 ` Cong Wang
2020-09-03 8:39 ` Paolo Abeni
2020-09-03 17:43 ` Cong Wang
2020-09-04 5:07 ` John Fastabend
2020-09-10 20:15 ` Cong Wang
2020-09-10 21:07 ` John Fastabend
2020-09-10 21:40 ` Paolo Abeni
2021-04-02 19:25 ` Jiri Kosina
2021-04-02 19:33 ` Josh Hunt
[not found] ` <20210403003537.2032-1-hdanton@sina.com>
2021-04-03 12:23 ` Jiri Kosina
2021-04-06 0:55 ` Yunsheng Lin
2021-04-06 7:06 ` Michal Kubecek
2021-04-06 10:13 ` Juergen Gross
2021-04-06 12:17 ` Yunsheng Lin
2021-04-06 1:49 ` Cong Wang
2021-04-06 2:46 ` Yunsheng Lin
2021-04-06 7:31 ` Michal Kubecek
2021-04-06 12:24 ` Yunsheng Lin
[not found] ` <20200903101957.428-1-hdanton@sina.com>
2020-09-04 3:20 ` Kehuan Feng
2020-09-10 20:19 ` Cong Wang
2020-09-14 2:10 ` Yunsheng Lin
2020-09-17 19:52 ` Cong Wang
2020-09-18 2:06 ` Kehuan Feng
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