Re: [PATCH] freebsd: Add support for multiple dpdk instances on FreeBSD

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, May 03, 2024 at 09:46:15AM +0000, Tom Jones wrote:
> Add support to the contigmem module on FreeBSD for multiple concurrent
> files, this enables running multiple dpdk instances with the nic_uio
> driver.
> 
> Add relevant parts in dpdk to support this.
> 
> Signed-off-by: Tom Jones <thj@freebsd.org>
> ---
>  config/rte_config.h                  |   2 +
>  kernel/freebsd/contigmem/contigmem.c | 225 ++++++++++++++++++---------
>  lib/eal/common/eal_common_options.c  |   2 +
>  lib/eal/freebsd/eal.c                |  12 ++
>  lib/eal/freebsd/eal_hugepage_info.c  |  12 +-
>  lib/eal/freebsd/eal_memory.c         |   3 +-
>  6 files changed, 180 insertions(+), 76 deletions(-)
> 
Hi Tom,

on testing this out the biggest gap I see is that we need a documentation
update for it. In V3 can you please update the FreeBSD GSG doc with some
details about how to use this feature.

Also, on first run using testpmd, the application failed to start, as I was
missing a file-prefix option. At minimum I think the code needs to default
the file-prefix on BSD to "contigmem0", so that when running a standalone
app as before, it "just works". An idea for backward compatibility here
that may help us, is to omit the "0" for contigmem0 device. That would mean
that an older DPDK app will work with a newer kernel driver, and vice
versa.

Beyond that, I'm not sure how to get multiple processes working right now
(hence the doc update request!). When I run a second instance of DPDK on my
system with "--file-prefix=contigmem1", I get errors about the shared
config file in "/var/run/dpdk/rte/config".

/Bruce