From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: David Howells <dhowells@redhat.com>,
Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: dhowells@redhat.com, Matthew Wilcox <willy@infradead.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Christoph Hellwig <hch@infradead.org>,
Jens Axboe <axboe@kernel.dk>, Jeff Layton <jlayton@kernel.org>,
Christian Brauner <brauner@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH 03/28] tcp: Support MSG_SPLICE_PAGES
Date: Thu, 16 Mar 2023 15:00:46 -0400 [thread overview]
Message-ID: <6413675eedcfa_33bc9d208e9@willemb.c.googlers.com.notmuch> (raw)
In-Reply-To: <811534.1678992280@warthog.procyon.org.uk>
David Howells wrote:
> Willem de Bruijn <willemdebruijn.kernel@gmail.com> wrote:
>
> > The commit message mentions MSG_SPLICE_PAGES as an internal flag.
> >
> > It can be passed from userspace. The code anticipates that and checks
> > preconditions.
>
> Should I add a separate field in the in-kernel msghdr struct for such internal
> flags? That would also avoid putting an internal flag in the same space as
> the uapi flags.
That would work, if no cost to common paths that don't need it.
A not very pretty alternative would be to add an an extra arg to each
sendmsg handler that is used only when called from sendpage.
There are a few other internal MSG_.. flags, such as
MSG_SENDPAGE_NOPOLICY. Those are all limited to sendpage, and ignored
in sendmsg, I think. Which would explain why it was clearly safe to
add them.
next prev parent reply other threads:[~2023-03-16 19:00 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-16 15:25 [RFC PATCH 00/28] splice, net: Replace sendpage with sendmsg(MSG_SPLICE_PAGES) David Howells
2023-03-16 15:25 ` [RFC PATCH 01/28] net: Declare MSG_SPLICE_PAGES internal sendmsg() flag David Howells
2023-03-16 15:25 ` [RFC PATCH 02/28] Add a special allocator for staging netfs protocol to MSG_SPLICE_PAGES David Howells
2023-03-16 17:28 ` Matthew Wilcox
2023-03-16 18:00 ` David Howells
2023-03-16 15:25 ` [RFC PATCH 03/28] tcp: Support MSG_SPLICE_PAGES David Howells
2023-03-16 18:37 ` Willem de Bruijn
2023-03-16 18:44 ` David Howells
2023-03-16 19:00 ` Willem de Bruijn [this message]
2023-03-21 0:38 ` David Howells
2023-03-21 14:22 ` Willem de Bruijn
2023-03-22 13:56 ` [RFC PATCH 0/3] net: Drop size arg from ->sendmsg() and pass msghdr into __ip{,6}_append_data() David Howells
2023-03-22 13:56 ` [RFC PATCH 1/3] net: Drop the size argument from ->sendmsg() David Howells
2023-03-22 13:56 ` [RFC PATCH 2/3] ip: Make __ip{,6}_append_data() and co. take a msghdr* David Howells
2023-03-22 13:56 ` [RFC PATCH 3/3] net: Declare MSG_SPLICE_PAGES internal sendmsg() flag David Howells
2023-03-23 1:17 ` [RFC PATCH 0/3] net: Drop size arg from ->sendmsg() and pass msghdr into __ip{,6}_append_data() Willem de Bruijn
2023-03-16 15:25 ` [RFC PATCH 04/28] tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGES David Howells
2023-03-16 15:25 ` [RFC PATCH 05/28] tcp_bpf: Inline do_tcp_sendpages as it's now a wrapper around tcp_sendmsg David Howells
2023-03-16 15:25 ` [RFC PATCH 06/28] espintcp: Inline do_tcp_sendpages() David Howells
2023-03-16 15:25 ` [RFC PATCH 07/28] tls: " David Howells
2023-03-16 15:25 ` [RFC PATCH 08/28] siw: " David Howells
2023-03-16 15:25 ` [RFC PATCH 09/28] tcp: Fold do_tcp_sendpages() into tcp_sendpage_locked() David Howells
2023-03-16 15:26 ` [RFC PATCH 10/28] ip, udp: Support MSG_SPLICE_PAGES David Howells
2023-03-16 15:26 ` [RFC PATCH 11/28] udp: Convert udp_sendpage() to use MSG_SPLICE_PAGES David Howells
2023-03-16 15:26 ` [RFC PATCH 12/28] af_unix: Support MSG_SPLICE_PAGES David Howells
2023-03-16 15:26 ` [RFC PATCH 13/28] crypto: af_alg: Indent the loop in af_alg_sendmsg() David Howells
2023-03-16 15:26 ` [RFC PATCH 14/28] crypto: af_alg: Support MSG_SPLICE_PAGES David Howells
2023-03-16 15:26 ` [RFC PATCH 15/28] crypto: af_alg: Convert af_alg_sendpage() to use MSG_SPLICE_PAGES David Howells
2023-03-16 15:26 ` [RFC PATCH 16/28] splice, net: Use sendmsg(MSG_SPLICE_PAGES) rather than ->sendpage() David Howells
2023-03-16 15:26 ` [RFC PATCH 17/28] Remove file->f_op->sendpage David Howells
2023-03-16 15:26 ` [RFC PATCH 18/28] siw: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage to transmit David Howells
2023-03-16 15:26 ` [RFC PATCH 19/28] ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage David Howells
2023-03-16 15:26 ` [RFC PATCH 20/28] iscsi: " David Howells
2023-03-16 15:26 ` [RFC PATCH 21/28] tcp_bpf: Make tcp_bpf_sendpage() go through tcp_bpf_sendmsg(MSG_SPLICE_PAGES) David Howells
2023-03-16 15:26 ` [RFC PATCH 22/28] net: Use sendmsg(MSG_SPLICE_PAGES) not sendpage in skb_send_sock() David Howells
2023-03-16 15:26 ` [RFC PATCH 23/28] algif: Remove hash_sendpage*() David Howells
2023-03-17 2:40 ` Herbert Xu
2023-03-24 16:47 ` David Howells
2023-03-25 6:00 ` Herbert Xu
2023-03-25 7:44 ` David Howells
2023-03-25 9:21 ` Herbert Xu
2023-03-16 15:26 ` [RFC PATCH 24/28] ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage() David Howells
2023-03-16 15:26 ` [RFC PATCH 25/28] rds: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage David Howells
2023-03-16 15:26 ` [RFC PATCH 26/28] dlm: " David Howells
2023-03-16 15:26 ` [RFC PATCH 27/28] sunrpc: Use sendmsg(MSG_SPLICE_PAGES) rather then sendpage David Howells
2023-03-16 16:17 ` Trond Myklebust
2023-03-16 17:10 ` Chuck Lever III
2023-03-16 17:28 ` David Howells
2023-03-16 17:41 ` Chuck Lever III
2023-03-16 21:21 ` David Howells
2023-03-17 15:29 ` Chuck Lever III
2023-03-16 16:24 ` David Howells
2023-03-16 18:06 ` David Howells
2023-03-16 19:01 ` Trond Myklebust
2023-03-22 13:10 ` David Howells
2023-03-22 18:15 ` [RFC PATCH] iov_iter: Add an iterator-of-iterators David Howells
2023-03-22 18:47 ` Trond Myklebust
2023-03-22 18:49 ` Matthew Wilcox
2023-03-16 15:26 ` [RFC PATCH 28/28] sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) David Howells
2023-03-16 15:57 ` Marc Kleine-Budde
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