From: David Laight <David.Laight@ACULAB.COM> To: 'Mina Almasry' <almasrymina@google.com>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>, "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>, "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>, "linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org> Cc: "David S. Miller" <davem@davemloft.net>, "Eric Dumazet" <edumazet@google.com>, "Jakub Kicinski" <kuba@kernel.org>, "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>, "Willem de Bruijn" <willemb@google.com>, "Kaiyuan Zhang" <kaiyuanz@google.com> Subject: RE: [RFC PATCH v3 09/12] net: add support for skbs with unreadable frags Date: Wed, 8 Nov 2023 14:43:23 +0000 [thread overview] Message-ID: <1478ddd0902941fba8316e8883de2758@AcuMS.aculab.com> (raw) In-Reply-To: <20231106024413.2801438-10-almasrymina@google.com> From: Mina Almasry > Sent: 06 November 2023 02:44 > > For device memory TCP, we expect the skb headers to be available in host > memory for access, and we expect the skb frags to be in device memory > and unaccessible to the host. We expect there to be no mixing and > matching of device memory frags (unaccessible) with host memory frags > (accessible) in the same skb. > > Add a skb->devmem flag which indicates whether the frags in this skb > are device memory frags or not. > ... > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 1fae276c1353..8fb468ff8115 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -805,6 +805,8 @@ typedef unsigned char *sk_buff_data_t; > * @csum_level: indicates the number of consecutive checksums found in > * the packet minus one that have been verified as > * CHECKSUM_UNNECESSARY (max 3) > + * @devmem: indicates that all the fragments in this skb are backed by > + * device memory. > * @dst_pending_confirm: need to confirm neighbour > * @decrypted: Decrypted SKB > * @slow_gro: state present at GRO time, slower prepare step required > @@ -991,7 +993,7 @@ struct sk_buff { > #if IS_ENABLED(CONFIG_IP_SCTP) > __u8 csum_not_inet:1; > #endif > - > + __u8 devmem:1; > #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS) > __u16 tc_index; /* traffic control index */ > #endif > @@ -1766,6 +1768,12 @@ static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) > __skb_zcopy_downgrade_managed(skb); > } Doesn't that bloat struct sk_buff? I'm not sure there are any spare bits available. Although CONFIG_NET_SWITCHDEV and CONFIG_NET_SCHED seem to already add padding. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
WARNING: multiple messages have this Message-ID (diff)
From: David Laight <David.Laight@ACULAB.COM> To: 'Mina Almasry' <almasrymina@google.com>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>, "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>, "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>, "linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org> Cc: "Willem de Bruijn" <willemdebruijn.kernel@gmail.com>, "Kaiyuan Zhang" <kaiyuanz@google.com>, "Jeroen de Borst" <jeroendb@google.com>, "Jesper Dangaard Brouer" <hawk@kernel.org>, "Arnd Bergmann" <arnd@arndb.de>, "Christian König" <christian.koenig@amd.com>, "David Ahern" <dsahern@kernel.org>, "Ilias Apalodimas" <ilias.apalodimas@linaro.org>, "Willem de Bruijn" <willemb@google.com>, "Sumit Semwal" <sumit.semwal@linaro.org>, "Eric Dumazet" <edumazet@google.com>, "Shakeel Butt" <shakeelb@google.com>, "Praveen Kaligineedi" <pkaligineedi@google.com>, "Jakub Kicinski" <kuba@kernel.org>, "Paolo Abeni" <pabeni@redhat.com>, "Shuah Khan" <shuah@kernel.org>, "David S. Miller" <davem@davemloft.net> Subject: RE: [RFC PATCH v3 09/12] net: add support for skbs with unreadable frags Date: Wed, 8 Nov 2023 14:43:23 +0000 [thread overview] Message-ID: <1478ddd0902941fba8316e8883de2758@AcuMS.aculab.com> (raw) In-Reply-To: <20231106024413.2801438-10-almasrymina@google.com> From: Mina Almasry > Sent: 06 November 2023 02:44 > > For device memory TCP, we expect the skb headers to be available in host > memory for access, and we expect the skb frags to be in device memory > and unaccessible to the host. We expect there to be no mixing and > matching of device memory frags (unaccessible) with host memory frags > (accessible) in the same skb. > > Add a skb->devmem flag which indicates whether the frags in this skb > are device memory frags or not. > ... > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 1fae276c1353..8fb468ff8115 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -805,6 +805,8 @@ typedef unsigned char *sk_buff_data_t; > * @csum_level: indicates the number of consecutive checksums found in > * the packet minus one that have been verified as > * CHECKSUM_UNNECESSARY (max 3) > + * @devmem: indicates that all the fragments in this skb are backed by > + * device memory. > * @dst_pending_confirm: need to confirm neighbour > * @decrypted: Decrypted SKB > * @slow_gro: state present at GRO time, slower prepare step required > @@ -991,7 +993,7 @@ struct sk_buff { > #if IS_ENABLED(CONFIG_IP_SCTP) > __u8 csum_not_inet:1; > #endif > - > + __u8 devmem:1; > #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS) > __u16 tc_index; /* traffic control index */ > #endif > @@ -1766,6 +1768,12 @@ static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) > __skb_zcopy_downgrade_managed(skb); > } Doesn't that bloat struct sk_buff? I'm not sure there are any spare bits available. Although CONFIG_NET_SWITCHDEV and CONFIG_NET_SCHED seem to already add padding. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2023-11-08 14:43 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 [this message] 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 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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