On 11/8/26 16:22, Stephen Hemminger wrote:
On Sat, 7 Nov 2026 11:11:54 +0000
Frank Dressler <[email protected]> wrote:
On 11/6/26 14:27, Bing Zhao wrote:
> The PACKET_IGNORE_OUTGOING socket option is used unconditionally,
> but it was only added to the uapi headers in Linux 4.20. The build
> fails on distributions shipping older kernel headers, like RHEL 8
> (kernel-headers-4.18.0-193.el8, gcc 8.5.0):
On 11/6/26 16:06, Frank Dressler wrote:
> If RHEL 8 uses Linux 4.18, [...]
> If DPDK needs to stay compatible with RHEL 8, [...]
Short version: RHEL itself does't seem to ship any DPDK that is too
new for its kernel. The RHEL 8 compatibility requirement may instead
come from NVIDIA's DOCA, which ships DPDK 26.03 on RHEL 8. If so, the
question is whether upstream DPDK should support that combination, or
whether it is better handled on the DOCA side. Details below.
Bing Zhao, is that the use case behind the patch?
Details:
I read too much into Bing Zhao's statement that the new code does not
build with the RHEL 8 kernel. That statement is true.I incorrectly
assumed RHEL itself ships a DPDK version that is too new for its
kernel, which is not the case.
The important parts that were missed here.
- flag should not be accepted if underlying kernel does not support it.
- failure should be at compile time not runtime.
Either remove this part:
...>
Or add a bunch of #ifdef like this.
But should these changes go into DPDK or NVIDIA's DOCA?
DPDK's current code requires no patch since the code works with the
kernel versions required by DPDK, i.e. Linux >= v5.4.
NVIDIA's DOCA, however, ships current DPDK to RHEL 8 which comes with
kernel v4.18 that is unsupported since DPDK v24.07. The latest release
is DOCA 3.5.0 which ships DPDK v26.03 to RHEL 8 which is not supported
by DPDK.
I think that NVIDIA should add a patch to DOCA's DPDK version or drop
support for RHEL 8 instead of requiring DPDK to be compatible with Linux
v4.18.
Because if DPDK was required to support all the distributions NVIDIA
ships DOCA for, developers would need to check what kernels all those
distributions ship with to find the oldest one. DPDK's kernel
requirement would then need to be changed from "Kernel version >= 5.4"
to "Kernel version min(5.4, whatever NVIDIA needs) >=".
