On Wed, Mar 1, 2023 at 4:35 PM Alejandro Colomar <alx.manpages@xxxxxxxxx> wrote:
>
> Hi Willem,
>
> On 3/1/23 22:11, Willem de Bruijn wrote:
> > From: Willem de Bruijn <willemb@xxxxxxxxxx>
> >
> > UDP_SEGMENT was added in commit bec1f6f69736
> > ("udp: generate gso with UDP_SEGMENT")
> >
> > $ git describe --contains bec1f6f69736
> > linux/v4.18-rc1~114^2~377^2~8
> >
> > Kernel source has example code in tools/testing/selftests/net/udpgso*
> >
> > Per https://www.kernel.org/doc/man-pages/patches.html,
> > "Describe how you obtained the information in your patch":
> > I am the author of the above commit and follow-ons.
> >
> > Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
> > ---
> > man7/udp.7 | 25 +++++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> >
> > diff --git a/man7/udp.7 b/man7/udp.7
> > index 5822bc551fdf..ec16306df605 100644
> > --- a/man7/udp.7
> > +++ b/man7/udp.7
> > @@ -204,6 +204,31 @@ portable.
> > .\" UDP_ENCAP_ESPINUDP draft-ietf-ipsec-udp-encaps-06
> > .\" UDP_ENCAP_L2TPINUDP rfc2661
> > .\" FIXME Document UDP_NO_CHECK6_TX and UDP_NO_CHECK6_RX, added in Linux 3.16
> > +.TP
> > +.BR UDP_SEGMENT " (since Linux 4.18)"
> > +Enables UDP segmentation offload.
> > +Segmentation offload reduces
> > +.BR send(2)
> > +cost by transferring multiple datagrams worth of data as a single
> > +large packet through the kernel transmit path, even when that
>
> Please use semantic newlines. See man-pages(7):
>
> Use semantic newlines
> In the source of a manual page, new sentences should be started
> on new lines, long sentences should be split into lines at
> clause breaks (commas, semicolons, colons, and so on), and long
> clauses should be split at phrase boundaries. This convention,
> sometimes known as "semantic newlines", makes it easier to see
> the effect of patches, which often operate at the level of in‐
> dividual sentences, clauses, or phrases.
>
>
> > +exceeds MTU.
> > +As late as possible, the large packet is split by segment size into a
> > +series of datagrams.
> > +This segmentation offload step is deferred to hardware if supported,
> > +else performed in software.
> > +This option takes a value between 0 and USHRT_MAX that sets the
> > +segment size: the size of datagram payload, excluding the UDP header.
> > +The segment size must be chosen such that at most 64 datagrams are
> > +sent in a single call and that the datagrams after segmentation meet
> > +the same MTU rules that apply to datagrams sent without this option.
> > +Segmentation offload depends on checksum offload, as datagram
> > +checksums are computed after segmentation.
> > +The option may also be set for individual
> > +.BR sendmsg(2)
>
> There should be a space between the bold part and the roman part:
>
> .BR foo (2)
>
> Otherwise, it all gets printed in bold.
Thanks Alex. I'll leave this open for other comments for a bit, but
will address both points in both patches in v2.
