| Message ID | 20230302154808.2139031-1-willemdebruijn.kernel@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [manpages,v2,1/2] udp.7: add UDP_SEGMENT | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Thu, Mar 02, 2023 at 10:48:07AM -0500, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb@google.com> > > 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@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com>
Hi Willem, On 3/2/23 16:48, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb@google.com> > > 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@google.com> Patch applied, with some minor tweaks and Simon's review tag. Cheers, Alex > > --- > > Changes v1->v2 > - semantic newlines: also break on comma and colon > - remove bold: section number following function name > - add bold: special macro USHRT_MAX > --- > man7/udp.7 | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/man7/udp.7 b/man7/udp.7 > index 5822bc551fdf..6646c1e96bb0 100644 > --- a/man7/udp.7 > +++ b/man7/udp.7 > @@ -204,6 +204,34 @@ 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 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 > +.BR 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) > +calls by passing it as a > +.BR cmsg (7). > +A value of zero disables the feature. > +This option should not be used in code intended to be portable. > .SS Ioctls > These ioctls can be accessed using > .BR ioctl (2).
Hi Willem, On 3/2/23 16:48, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb@google.com> > > 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@google.com> > It doesn't apply. Can you please rebase on top of master? Thanks, Alex > --- > > Changes v1->v2 > - semantic newlines: also break on comma and colon > - remove bold: section number following function name > - add bold: special macro USHRT_MAX > --- > man7/udp.7 | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/man7/udp.7 b/man7/udp.7 > index 5822bc551fdf..6646c1e96bb0 100644 > --- a/man7/udp.7 > +++ b/man7/udp.7 > @@ -204,6 +204,34 @@ 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 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 > +.BR 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) > +calls by passing it as a > +.BR cmsg (7). > +A value of zero disables the feature. > +This option should not be used in code intended to be portable. > .SS Ioctls > These ioctls can be accessed using > .BR ioctl (2).
On 3/6/23 14:30, Alejandro Colomar wrote: > Hi Willem, > > On 3/2/23 16:48, Willem de Bruijn wrote: >> From: Willem de Bruijn <willemb@google.com> >> >> 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@google.com> >> > > It doesn't apply. Can you please rebase on top of master? Oops, sorry, I tried to apply 1/2 twice, instead of 1/2 and 2/2 :-) Ignore that. Cheers, Alex > > Thanks, > > Alex > >> --- >> >> Changes v1->v2 >> - semantic newlines: also break on comma and colon >> - remove bold: section number following function name >> - add bold: special macro USHRT_MAX >> --- >> man7/udp.7 | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/man7/udp.7 b/man7/udp.7 >> index 5822bc551fdf..6646c1e96bb0 100644 >> --- a/man7/udp.7 >> +++ b/man7/udp.7 >> @@ -204,6 +204,34 @@ 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 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 >> +.BR 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) >> +calls by passing it as a >> +.BR cmsg (7). >> +A value of zero disables the feature. >> +This option should not be used in code intended to be portable. >> .SS Ioctls >> These ioctls can be accessed using >> .BR ioctl (2).
Alejandro Colomar wrote: > > > On 3/6/23 14:30, Alejandro Colomar wrote: > > Hi Willem, > > > > On 3/2/23 16:48, Willem de Bruijn wrote: > >> From: Willem de Bruijn <willemb@google.com> > >> > >> 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@google.com> > >> > > > > It doesn't apply. Can you please rebase on top of master? > > Oops, sorry, I tried to apply 1/2 twice, instead of 1/2 and 2/2 :-) > Ignore that. Great. Thanks for applying, and for fixing up the cmsg references, Alex.
diff --git a/man7/udp.7 b/man7/udp.7 index 5822bc551fdf..6646c1e96bb0 100644 --- a/man7/udp.7 +++ b/man7/udp.7 @@ -204,6 +204,34 @@ 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 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 +.BR 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) +calls by passing it as a +.BR cmsg (7). +A value of zero disables the feature. +This option should not be used in code intended to be portable. .SS Ioctls These ioctls can be accessed using .BR ioctl (2).