Re: [PATCH v2] eal: fix undetected NUMA nodes

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

On Wed, Mar 05, 2025 at 04:24:58PM +0000, Bruce Richardson wrote:
> In cases where the number of cores on a given socket is greater than
> RTE_MAX_LCORES, then EAL will be unaware of all the sockets/numa nodes
> on a system. Fix this limitation by having the EAL probe the NUMA node
> for cores it isn't going to use, and recording that for completeness.
> 
> This is necessary as memory is tracked per node, and with the --lcores
> parameters our app lcores may be on different sockets than the lcore ids
> may imply. For example, lcore 0 is on socket zero, but if app is run
> with --lcores=0@64, then DPDK lcore 0 may be on socket one, so DPDK
> needs to be aware of that socket.
> 
> Fixes: 952b20777255 ("eal: provide API for querying valid socket ids")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> ---
> v2: handle case where RTE_MAX_LCORE > CPU_SETSIZE (i.e. >1024)
> ---
>  lib/eal/common/eal_common_lcore.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
>
Ping for review.

For anyone wanting to test:
	 To reproduce the issue, do a build of DPDK with max_lcores option
set to less than the number of physical cores you have on a socket.
Then when running DPDK, the number of NUMA nodes printed at startup
will be incorrect. Applying this patch will then correct that.

Thanks,
/Bruce