From: Alexei Starovoitov <ast@plumgrid.com>
To: Cong Wang <cwang@twopensource.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jamal Hadi Salim <jhs@mojatatu.com>,
John Fastabend <john.r.fastabend@intel.com>,
netdev <netdev@vger.kernel.org>
Subject: Re: [RFC 1/3] tc: fix return values of ingress qdisc
Date: Wed, 22 Apr 2015 15:04:03 -0700 [thread overview]
Message-ID: <55381AD3.30209@plumgrid.com> (raw)
In-Reply-To: <CAHA+R7NwAdc81bFSoqvXsTpzod0vzT-PV38_Q0N0WTUVGFUY-g@mail.gmail.com>
On 4/21/15 9:59 PM, Cong Wang wrote:
> On Tue, Apr 21, 2015 at 12:27 PM, Alexei Starovoitov <ast@plumgrid.com> wrote:
>> ingress qdisc should return NET_XMIT_* values just like all other qdiscs.
>>
>
> XMIT already means egress...
may be then it should be renamed as well.
from include/linux/netdevice.h:
/* qdisc ->enqueue() return codes. */
#define NET_XMIT_SUCCESS 0x00
...
the point is that qdisc->enqeue() must return NET_XMIT_* values.
ingress qdisc is violating this and therefore should be fixed.
>> Since it's invoked via qdisc_enqueue_root() (which suppose to return
>> only NET_XMIT_* values as well), it was working by accident,
>> since TC_ACT_* values fit within NET_XMIT_MASK.
>>
>
> Why not just add a BUILD_BUG_ON() to capture this?
ingress qdisc returning TC_ACT_* values is an obvious layering
violation. I'm puzzled why it's been this way for so long.
Adding BUILD_BUG_ON is not an option.
next prev parent reply other threads:[~2015-04-22 22:04 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-21 19:27 [RFC 0/3] tc cleanup? Alexei Starovoitov
2015-04-21 19:27 ` [RFC 1/3] tc: fix return values of ingress qdisc Alexei Starovoitov
2015-04-22 4:59 ` Cong Wang
2015-04-22 22:04 ` Alexei Starovoitov [this message]
2015-04-22 23:29 ` Cong Wang
2015-04-23 8:46 ` Thomas Graf
2015-04-21 19:27 ` [RFC 2/3] tc: deprecate TC_ACT_QUEUED Alexei Starovoitov
2015-04-22 5:02 ` Cong Wang
2015-04-22 7:43 ` Daniel Borkmann
2015-04-22 22:22 ` Alexei Starovoitov
2015-04-22 23:39 ` Cong Wang
2015-04-23 2:46 ` Alexei Starovoitov
2015-04-23 7:13 ` Daniel Borkmann
2015-04-23 18:12 ` Cong Wang
2015-04-23 18:21 ` Daniel Borkmann
2015-04-23 18:30 ` Cong Wang
2015-04-23 20:45 ` Jamal Hadi Salim
2015-04-23 21:20 ` Florian Westphal
2015-04-23 22:13 ` Alexei Starovoitov
2015-04-23 22:33 ` Cong Wang
2015-04-23 22:51 ` Jamal Hadi Salim
2015-04-24 0:59 ` Alexei Starovoitov
2015-04-24 3:37 ` Cong Wang
2015-04-24 8:12 ` Daniel Borkmann
2015-04-27 12:31 ` Jamal Hadi Salim
2015-04-21 19:27 ` [RFC 3/3] tc: cleanup tc_classify Alexei Starovoitov
2015-04-22 5:05 ` Cong Wang
2015-04-22 22:27 ` Alexei Starovoitov
2015-04-22 23:38 ` Cong Wang
2015-04-23 8:49 ` Thomas Graf
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