From: David Ahern <dsahern@kernel.org>
To: Mina Almasry <almasrymina@google.com>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, virtualization@lists.linux.dev,
kvm@vger.kernel.org, linux-kselftest@vger.kernel.org,
"Donald Hunter" <donald.hunter@gmail.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Simon Horman" <horms@kernel.org>,
"Jonathan Corbet" <corbet@lwn.net>,
"Andrew Lunn" <andrew+netdev@lunn.ch>,
"Jeroen de Borst" <jeroendb@google.com>,
"Harshitha Ramamurthy" <hramamurthy@google.com>,
"Kuniyuki Iwashima" <kuniyu@amazon.com>,
"Willem de Bruijn" <willemb@google.com>,
"Neal Cardwell" <ncardwell@google.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Stefano Garzarella" <sgarzare@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
"Xuan Zhuo" <xuanzhuo@linux.alibaba.com>,
"Eugenio Pérez" <eperezma@redhat.com>,
"Shuah Khan" <shuah@kernel.org>,
sdf@fomichev.me, asml.silence@gmail.com, dw@davidwei.uk,
"Jamal Hadi Salim" <jhs@mojatatu.com>,
"Victor Nogueira" <victor@mojatatu.com>,
"Pedro Tammela" <pctammela@mojatatu.com>,
"Samiullah Khawaja" <skhawaja@google.com>,
"Kaiyuan Zhang" <kaiyuanz@google.com>
Subject: Re: [PATCH net-next v5 3/9] net: devmem: Implement TX path
Date: Tue, 25 Feb 2025 11:03:27 -0700 [thread overview]
Message-ID: <a003b144-0abf-4274-abff-a6e391a3e20b@kernel.org> (raw)
In-Reply-To: <CAHS8izNfNJLrMtdR0je3DsXDAvP2Hs8HfKf5Jq7_kQJsVUbrzg@mail.gmail.com>
On 2/25/25 10:41 AM, Mina Almasry wrote:
> On Tue, Feb 25, 2025 at 5:04 AM Paolo Abeni <pabeni@redhat.com> wrote:
>>
>> On 2/22/25 8:15 PM, Mina Almasry wrote:
>> [...]
>>> @@ -119,6 +122,13 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding)
>>> unsigned long xa_idx;
>>> unsigned int rxq_idx;
>>>
>>> + xa_erase(&net_devmem_dmabuf_bindings, binding->id);
>>> +
>>> + /* Ensure no tx net_devmem_lookup_dmabuf() are in flight after the
>>> + * erase.
>>> + */
>>> + synchronize_net();
>>
>> Is the above statement always true? can the dmabuf being stuck in some
>> qdisc? or even some local socket due to redirect?
>>
>
> Yes, we could have have netmems in the TX path in the qdisc or waiting
> for retransmits that still have references to the dmabuf, and that's
> fine here I think.
skbs with references to netmem from a dmabuf can get stuck in retransmit
queues for a long time. The comment should at least acknowledge that.
next prev parent reply other threads:[~2025-02-25 18:03 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-22 19:15 [PATCH net-next v5 0/9] Device memory TCP TX Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 1/9] net: add get_netmem/put_netmem support Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 2/9] net: devmem: TCP tx netlink api Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 3/9] net: devmem: Implement TX path Mina Almasry
2025-02-24 17:38 ` Stanislav Fomichev
2025-02-25 13:04 ` Paolo Abeni
2025-02-25 17:41 ` Mina Almasry
2025-02-25 18:03 ` David Ahern [this message]
2025-02-25 18:54 ` Mina Almasry
2025-02-26 15:20 ` David Ahern
2025-02-22 19:15 ` [PATCH net-next v5 4/9] net: devmem: make dmabuf unbinding scheduled work Mina Almasry
2025-02-25 13:08 ` Paolo Abeni
2025-02-22 19:15 ` [PATCH net-next v5 5/9] net: add devmem TCP TX documentation Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 6/9] net: enable driver support for netmem TX Mina Almasry
2025-02-24 17:15 ` Stanislav Fomichev
2025-02-22 19:15 ` [PATCH net-next v5 7/9] gve: add netmem TX support to GVE DQO-RDA mode Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 8/9] net: check for driver support in netmem TX Mina Almasry
2025-02-22 19:15 ` [PATCH net-next v5 9/9] selftests: ncdevmem: Implement devmem TCP TX Mina Almasry
2025-02-24 17:15 ` Stanislav Fomichev
2025-02-24 17:19 ` Mina Almasry
2025-02-24 17:54 ` Stanislav Fomichev
2025-02-25 2:53 ` [PATCH net-next v5 0/9] Device memory " Lei Yang
2025-02-25 3:19 ` Mina Almasry
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