From: David Miller <davem@davemloft.net>
To: jasowang@redhat.com
Cc: netdev@vger.kernel.org, mst@redhat.com, yuehaibing@huawei.com,
xiyou.wangcong@gmail.com, weiyongjun1@huawei.com,
eric.dumazet@gmail.com
Subject: Re: [PATCH net V2] tuntap: synchronize through tfiles array instead of tun->numqueues
Date: Wed, 08 May 2019 10:36:13 -0700 (PDT) [thread overview]
Message-ID: <20190508.103613.1782548019381525988.davem@davemloft.net> (raw)
In-Reply-To: <1557201816-19945-1-git-send-email-jasowang@redhat.com>
From: Jason Wang <jasowang@redhat.com>
Date: Tue, 7 May 2019 00:03:36 -0400
> @@ -1313,6 +1315,10 @@ static int tun_xdp_xmit(struct net_device *dev, int n,
>
> tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
> numqueues]);
> + if (!tfile) {
> + rcu_read_unlock();
> + return -ENXIO; /* Caller will free/return all frames */
> + }
>
> spin_lock(&tfile->tx_ring.producer_lock);
> for (i = 0; i < n; i++) {
The only way we can see a NULL here is if a detach happened in parallel,
and if that happens we should retry the tfile[] indexing after resampling
numqueues rather than dropping the packet.
next prev parent reply other threads:[~2019-05-08 17:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-07 4:03 [PATCH net V2] tuntap: synchronize through tfiles array instead of tun->numqueues Jason Wang
2019-05-07 4:54 ` Cong Wang
2019-05-07 6:19 ` Jason Wang
2019-05-07 14:41 ` Cong Wang
2019-05-08 2:54 ` Jason Wang
2019-05-09 5:34 ` Cong Wang
2019-05-09 12:55 ` Jason Wang
2019-05-08 4:16 ` Michael S. Tsirkin
2019-05-08 4:30 ` Jason Wang
2019-05-08 17:36 ` David Miller [this message]
2019-05-09 3:16 ` Jason Wang
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