From: Jakub Kicinski <kuba@kernel.org>
To: Mina Almasry <almasrymina@google.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
linaro-mm-sig@lists.linaro.org,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Paolo Abeni" <pabeni@redhat.com>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
"Arnd Bergmann" <arnd@arndb.de>,
"David Ahern" <dsahern@kernel.org>,
"Willem de Bruijn" <willemdebruijn.kernel@gmail.com>,
"Shuah Khan" <shuah@kernel.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Christian König" <christian.koenig@amd.com>,
"Shakeel Butt" <shakeelb@google.com>,
"Jeroen de Borst" <jeroendb@google.com>,
"Praveen Kaligineedi" <pkaligineedi@google.com>,
"Stanislav Fomichev" <sdf@google.com>
Subject: Re: [RFC PATCH v3 12/12] selftests: add ncdevmem, netcat for devmem TCP
Date: Fri, 10 Nov 2023 18:35:56 -0800 [thread overview]
Message-ID: <20231110183556.2b7b7502@kernel.org> (raw)
In-Reply-To: <CAHS8izNFnE8RGgBhKzxhVoKXtXgZGVQCLSdm4_dWNeH9Gx-WDQ@mail.gmail.com>
On Fri, 10 Nov 2023 18:27:08 -0800 Mina Almasry wrote:
> Thanks for the clear requirement. I clearly had something different in mind.
>
> Might be dumb suggestions, but instead of creating a new ndo that we
> maybe end up wanting to deprecate once the queue API is ready, how
> about we use either of those existing APIs?
>
> +void netdev_reset(struct net_device *dev)
> +{
> + int flags = ETH_RESET_ALL;
> + int err;
> +
> +#if 1
> + __dev_close(dev);
> + err = __dev_open(dev, NULL);
> +#else
> + err = dev->ethtool_ops->reset(dev, &flags);
> +#endif
> +}
> +
>
> I've tested both of these to work with GVE on both bind via the
> netlink API and unbind via the netlink socket close, but I'm not
> enough of an expert to tell if there is some bad side effect that can
> happen or something.
We generally don't accept drivers doing device reconfiguration with
full close() + open() because if the open() fails your machine
may be cut off.
There are drivers which do it, but they are either old... or weren't
reviewed hard enough.
The driver should allocate memory and whether else it can without
stopping the queues first. Once it has all those, stop the queues,
reconfigure with already allocated resources, start queues, free old.
Even without the queue API in place, good drivers do full device
reconfig this way. Hence my mind goes towards a new (temporary?)
ndo. It will be replaced by the queue API, but whoever implements
it for now has to follow this careful reconfig strategy...
WARNING: multiple messages have this Message-ID (diff)
From: Jakub Kicinski <kuba@kernel.org>
To: Mina Almasry <almasrymina@google.com>
Cc: dri-devel@lists.freedesktop.org,
"Eric Dumazet" <edumazet@google.com>,
"Stanislav Fomichev" <sdf@google.com>,
linux-kselftest@vger.kernel.org, "Shuah Khan" <shuah@kernel.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
linux-arch@vger.kernel.org,
"Willem de Bruijn" <willemdebruijn.kernel@gmail.com>,
"Jeroen de Borst" <jeroendb@google.com>,
"Paolo Abeni" <pabeni@redhat.com>,
linux-media@vger.kernel.org,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"Arnd Bergmann" <arnd@arndb.de>,
linaro-mm-sig@lists.linaro.org,
"Shakeel Butt" <shakeelb@google.com>,
netdev@vger.kernel.org, "David Ahern" <dsahern@kernel.org>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
"Praveen Kaligineedi" <pkaligineedi@google.com>,
"Christian König" <christian.koenig@amd.com>
Subject: Re: [RFC PATCH v3 12/12] selftests: add ncdevmem, netcat for devmem TCP
Date: Fri, 10 Nov 2023 18:35:56 -0800 [thread overview]
Message-ID: <20231110183556.2b7b7502@kernel.org> (raw)
In-Reply-To: <CAHS8izNFnE8RGgBhKzxhVoKXtXgZGVQCLSdm4_dWNeH9Gx-WDQ@mail.gmail.com>
On Fri, 10 Nov 2023 18:27:08 -0800 Mina Almasry wrote:
> Thanks for the clear requirement. I clearly had something different in mind.
>
> Might be dumb suggestions, but instead of creating a new ndo that we
> maybe end up wanting to deprecate once the queue API is ready, how
> about we use either of those existing APIs?
>
> +void netdev_reset(struct net_device *dev)
> +{
> + int flags = ETH_RESET_ALL;
> + int err;
> +
> +#if 1
> + __dev_close(dev);
> + err = __dev_open(dev, NULL);
> +#else
> + err = dev->ethtool_ops->reset(dev, &flags);
> +#endif
> +}
> +
>
> I've tested both of these to work with GVE on both bind via the
> netlink API and unbind via the netlink socket close, but I'm not
> enough of an expert to tell if there is some bad side effect that can
> happen or something.
We generally don't accept drivers doing device reconfiguration with
full close() + open() because if the open() fails your machine
may be cut off.
There are drivers which do it, but they are either old... or weren't
reviewed hard enough.
The driver should allocate memory and whether else it can without
stopping the queues first. Once it has all those, stop the queues,
reconfigure with already allocated resources, start queues, free old.
Even without the queue API in place, good drivers do full device
reconfig this way. Hence my mind goes towards a new (temporary?)
ndo. It will be replaced by the queue API, but whoever implements
it for now has to follow this careful reconfig strategy...
next prev parent reply other threads:[~2023-11-11 2:36 UTC|newest]
Thread overview: 254+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-06 2:43 [RFC PATCH v3 00/12] Device Memory TCP Mina Almasry
2023-11-06 2:43 ` Mina Almasry
2023-11-06 2:44 ` [RFC PATCH v3 01/12] net: page_pool: factor out releasing DMA from releasing the page Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 2:44 ` [RFC PATCH v3 02/12] net: page_pool: create hooks for custom page providers Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-07 7:44 ` Yunsheng Lin
2023-11-07 7:44 ` Yunsheng Lin
2023-11-09 11:09 ` Paolo Abeni
2023-11-09 11:09 ` Paolo Abeni
2023-11-10 23:19 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-13 3:28 ` Mina Almasry
2023-11-13 3:28 ` Mina Almasry
2023-11-13 22:10 ` Jakub Kicinski
2023-11-13 22:10 ` Jakub Kicinski
2023-11-06 2:44 ` [RFC PATCH v3 03/12] net: netdev netlink api to bind dma-buf to a net device Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-10 23:16 ` Jakub Kicinski
2023-11-10 23:16 ` Jakub Kicinski
2023-11-06 2:44 ` [RFC PATCH v3 04/12] netdev: support binding dma-buf to netdevice Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-07 7:46 ` Yunsheng Lin
2023-11-07 7:46 ` Yunsheng Lin
2023-11-07 21:59 ` Mina Almasry
2023-11-07 21:59 ` Mina Almasry
2023-11-08 3:40 ` Yunsheng Lin
2023-11-08 3:40 ` Yunsheng Lin
2023-11-09 2:22 ` Mina Almasry
2023-11-09 2:22 ` Mina Almasry
2023-11-09 9:29 ` Yunsheng Lin
2023-11-09 9:29 ` Yunsheng Lin
2023-11-08 23:47 ` David Wei
2023-11-08 23:47 ` David Wei
2023-11-09 2:25 ` Mina Almasry
2023-11-09 2:25 ` Mina Almasry
2023-11-09 8:29 ` Paolo Abeni
2023-11-09 8:29 ` Paolo Abeni
2023-11-10 2:59 ` Mina Almasry
2023-11-10 2:59 ` Mina Almasry
2023-11-10 7:38 ` Yunsheng Lin
2023-11-10 7:38 ` Yunsheng Lin
2023-11-10 9:45 ` Mina Almasry
2023-11-10 9:45 ` Mina Almasry
2023-11-10 23:19 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-11 2:19 ` Mina Almasry
2023-11-11 2:19 ` Mina Almasry
2023-11-06 2:44 ` [RFC PATCH v3 05/12] netdev: netdevice devmem allocator Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 23:44 ` David Ahern
2023-11-06 23:44 ` David Ahern
2023-11-07 22:10 ` Mina Almasry
2023-11-07 22:10 ` Mina Almasry
2023-11-07 22:55 ` David Ahern
2023-11-07 22:55 ` David Ahern
2023-11-07 23:03 ` Mina Almasry
2023-11-07 23:03 ` Mina Almasry
2023-11-09 1:15 ` David Wei
2023-11-09 1:15 ` David Wei
2023-11-10 14:26 ` Pavel Begunkov
2023-11-10 14:26 ` Pavel Begunkov
2023-11-11 17:19 ` David Ahern
2023-11-11 17:19 ` David Ahern
2023-11-14 16:09 ` Pavel Begunkov
2023-11-14 16:09 ` Pavel Begunkov
2023-11-09 1:00 ` David Wei
2023-11-09 1:00 ` David Wei
2023-11-08 3:48 ` Yunsheng Lin
2023-11-08 3:48 ` Yunsheng Lin
2023-11-09 1:41 ` Mina Almasry
2023-11-09 1:41 ` Mina Almasry
2023-11-07 7:45 ` Yunsheng Lin
2023-11-07 7:45 ` Yunsheng Lin
2023-11-09 8:44 ` Paolo Abeni
2023-11-09 8:44 ` Paolo Abeni
2023-11-06 2:44 ` [RFC PATCH v3 06/12] memory-provider: dmabuf devmem memory provider Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 21:02 ` Stanislav Fomichev
2023-11-06 21:02 ` Stanislav Fomichev
2023-11-06 23:49 ` David Ahern
2023-11-06 23:49 ` David Ahern
2023-11-08 0:02 ` Mina Almasry
2023-11-08 0:02 ` Mina Almasry
2023-11-08 0:10 ` David Ahern
2023-11-08 0:10 ` David Ahern
2023-11-10 23:16 ` Jakub Kicinski
2023-11-10 23:16 ` Jakub Kicinski
2023-11-13 4:54 ` Mina Almasry
2023-11-13 4:54 ` Mina Almasry
2023-11-06 2:44 ` [RFC PATCH v3 07/12] page-pool: device memory support Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-07 8:00 ` Yunsheng Lin
2023-11-07 8:00 ` Yunsheng Lin
2023-11-07 21:56 ` Mina Almasry
2023-11-07 21:56 ` Mina Almasry
2023-11-08 10:56 ` Yunsheng Lin
2023-11-08 10:56 ` Yunsheng Lin
2023-11-09 3:20 ` Mina Almasry
2023-11-09 3:20 ` Mina Almasry
2023-11-09 9:30 ` Yunsheng Lin
2023-11-09 9:30 ` Yunsheng Lin
2023-11-09 12:20 ` Mina Almasry
2023-11-09 12:20 ` Mina Almasry
2023-11-09 13:23 ` Yunsheng Lin
2023-11-09 13:23 ` Yunsheng Lin
2023-11-09 14:23 ` Christian König
2023-11-09 9:01 ` Paolo Abeni
2023-11-09 9:01 ` Paolo Abeni
2023-11-06 2:44 ` [RFC PATCH v3 08/12] net: support non paged skb frags Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-07 9:00 ` Yunsheng Lin
2023-11-07 9:00 ` Yunsheng Lin
2023-11-07 21:19 ` Mina Almasry
2023-11-07 21:19 ` Mina Almasry
2023-11-08 11:25 ` Yunsheng Lin
2023-11-08 11:25 ` Yunsheng Lin
2023-11-09 9:14 ` Paolo Abeni
2023-11-09 9:14 ` Paolo Abeni
2023-11-10 4:06 ` Mina Almasry
2023-11-10 4:06 ` Mina Almasry
2023-11-10 23:19 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-13 6:05 ` Mina Almasry
2023-11-13 6:05 ` Mina Almasry
2023-11-13 22:17 ` Jakub Kicinski
2023-11-13 22:17 ` Jakub Kicinski
2023-11-06 2:44 ` [RFC PATCH v3 09/12] net: add support for skbs with unreadable frags Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 18:47 ` Stanislav Fomichev
2023-11-06 18:47 ` Stanislav Fomichev
2023-11-06 19:34 ` David Ahern
2023-11-06 19:34 ` David Ahern
2023-11-06 20:31 ` Mina Almasry
2023-11-06 20:31 ` Mina Almasry
2023-11-06 21:59 ` Stanislav Fomichev
2023-11-06 21:59 ` Stanislav Fomichev
2023-11-06 22:18 ` Mina Almasry
2023-11-06 22:18 ` Mina Almasry
2023-11-06 22:59 ` Stanislav Fomichev
2023-11-06 22:59 ` Stanislav Fomichev
2023-11-06 23:14 ` Kaiyuan Zhang
2023-11-06 23:27 ` Mina Almasry
2023-11-06 23:27 ` Mina Almasry
2023-11-06 23:55 ` Stanislav Fomichev
2023-11-06 23:55 ` Stanislav Fomichev
2023-11-07 0:07 ` Willem de Bruijn
2023-11-07 0:07 ` Willem de Bruijn
2023-11-07 0:14 ` Stanislav Fomichev
2023-11-07 0:14 ` Stanislav Fomichev
2023-11-07 0:59 ` Stanislav Fomichev
2023-11-07 0:59 ` Stanislav Fomichev
2023-11-07 2:23 ` Willem de Bruijn
2023-11-07 2:23 ` Willem de Bruijn
2023-11-07 17:44 ` Stanislav Fomichev
2023-11-07 17:44 ` Stanislav Fomichev
2023-11-07 17:57 ` Willem de Bruijn
2023-11-07 17:57 ` Willem de Bruijn
2023-11-07 18:14 ` Stanislav Fomichev
2023-11-07 18:14 ` Stanislav Fomichev
2023-11-07 0:20 ` Mina Almasry
2023-11-07 0:20 ` Mina Almasry
2023-11-07 1:06 ` Stanislav Fomichev
2023-11-07 1:06 ` Stanislav Fomichev
2023-11-07 19:53 ` Mina Almasry
2023-11-07 19:53 ` Mina Almasry
2023-11-07 21:05 ` Stanislav Fomichev
2023-11-07 21:05 ` Stanislav Fomichev
2023-11-07 21:17 ` Eric Dumazet
2023-11-07 21:17 ` Eric Dumazet
2023-11-07 22:23 ` Stanislav Fomichev
2023-11-07 22:23 ` Stanislav Fomichev
2023-11-10 23:17 ` Jakub Kicinski
2023-11-10 23:17 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-07 1:09 ` David Ahern
2023-11-07 1:09 ` David Ahern
2023-11-06 23:37 ` David Ahern
2023-11-06 23:37 ` David Ahern
2023-11-07 0:03 ` Mina Almasry
2023-11-07 0:03 ` Mina Almasry
2023-11-06 20:56 ` Stanislav Fomichev
2023-11-06 20:56 ` Stanislav Fomichev
2023-11-07 0:16 ` David Ahern
2023-11-07 0:16 ` David Ahern
2023-11-07 0:23 ` Mina Almasry
2023-11-07 0:23 ` Mina Almasry
2023-11-08 14:43 ` David Laight
2023-11-08 14:43 ` David Laight
2023-11-06 2:44 ` [RFC PATCH v3 10/12] tcp: RX path for devmem TCP Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 18:44 ` Stanislav Fomichev
2023-11-06 18:44 ` Stanislav Fomichev
2023-11-06 19:29 ` Mina Almasry
2023-11-06 19:29 ` Mina Almasry
2023-11-06 21:14 ` Willem de Bruijn
2023-11-06 21:14 ` Willem de Bruijn
2023-11-06 22:34 ` Stanislav Fomichev
2023-11-06 22:34 ` Stanislav Fomichev
2023-11-06 22:55 ` Willem de Bruijn
2023-11-06 22:55 ` Willem de Bruijn
2023-11-06 23:32 ` Stanislav Fomichev
2023-11-06 23:32 ` Stanislav Fomichev
2023-11-06 23:55 ` David Ahern
2023-11-06 23:55 ` David Ahern
2023-11-07 0:02 ` Willem de Bruijn
2023-11-07 0:02 ` Willem de Bruijn
2023-11-07 23:55 ` Mina Almasry
2023-11-07 23:55 ` Mina Almasry
2023-11-08 0:01 ` David Ahern
2023-11-08 0:01 ` David Ahern
2023-11-09 2:39 ` Mina Almasry
2023-11-09 2:39 ` Mina Almasry
2023-11-09 16:07 ` Edward Cree
2023-11-09 16:07 ` Edward Cree
2023-12-08 20:12 ` Pavel Begunkov
2023-12-08 20:12 ` Pavel Begunkov
2023-11-09 11:05 ` Paolo Abeni
2023-11-09 11:05 ` Paolo Abeni
2023-11-10 23:16 ` Jakub Kicinski
2023-11-10 23:16 ` Jakub Kicinski
2023-12-08 20:28 ` Pavel Begunkov
2023-12-08 20:28 ` Pavel Begunkov
2023-12-08 20:09 ` Pavel Begunkov
2023-12-08 20:09 ` Pavel Begunkov
2023-11-06 21:17 ` Stanislav Fomichev
2023-11-06 21:17 ` Stanislav Fomichev
2023-11-08 15:36 ` Edward Cree
2023-11-08 15:36 ` Edward Cree
2023-11-09 10:52 ` Paolo Abeni
2023-11-09 10:52 ` Paolo Abeni
2023-11-10 23:19 ` Jakub Kicinski
2023-11-10 23:19 ` Jakub Kicinski
2023-11-06 2:44 ` [RFC PATCH v3 11/12] net: add SO_DEVMEM_DONTNEED setsockopt to release RX pages Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-06 2:44 ` [RFC PATCH v3 12/12] selftests: add ncdevmem, netcat for devmem TCP Mina Almasry
2023-11-06 2:44 ` Mina Almasry
2023-11-09 11:03 ` Paolo Abeni
2023-11-09 11:03 ` Paolo Abeni
2023-11-10 23:13 ` Jakub Kicinski
2023-11-10 23:13 ` Jakub Kicinski
2023-11-11 2:27 ` Mina Almasry
2023-11-11 2:27 ` Mina Almasry
2023-11-11 2:35 ` Jakub Kicinski [this message]
2023-11-11 2:35 ` Jakub Kicinski
2023-11-13 4:08 ` Mina Almasry
2023-11-13 4:08 ` Mina Almasry
2023-11-13 22:20 ` Jakub Kicinski
2023-11-13 22:20 ` Jakub Kicinski
2023-11-10 23:17 ` Jakub Kicinski
2023-11-10 23:17 ` Jakub Kicinski
2023-11-07 15:18 ` [RFC PATCH v3 00/12] Device Memory TCP David Ahern
2023-11-07 15:18 ` David Ahern
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