Re: [dpdk-users] rte_eal_memseg_init(), virtual memory usage and coredump size

[Li Feng <fengli@smartx.com>]

Hi Valerii,

You could upgrade your DPDK to the latest version.
I have submitted a patch to fix this issue some months ago.

Thanks,

Feng Li

On Mon, Jul 6, 2020 at 4:53 AM Valerii Malov <jazzvoid@gmail.com> wrote:
>
> Hi,
>
>
>
> I've noticed since upgrading to one of the recent DPDK versions (I think
> it was DPDK 19), Linux application started to allocate rather big chunks
> of virtual memory. This causes coredump file size to blow up, and
> playing around with coredump_filter doesn't seem to help, since this is
> not hugepages memory.
>
>
>
>
> After digging through initialization process, seems like
> rte_eal_memseg_init() is the culprit. It preallocates chunks for each
> memory "type", until it hits one of the ceilings, in my case it's
> default RTE_MAX_MEM_MB_PER_TYPE, which happens to be default 64
> gigabytes, so on 2 numa node system this results in nearly extra 128
> gigabytes of virtual memory.
>
> Surprisingly enough, in FreeBSD implementation of rte_eal_memseg_init()
> virtual memory usage seems to be a concern due to coredump file size
> specifically.
>
> Are there any ways to reduce the coredump file size apart from building
> DPDK with reduced RTE_MAX_MEM_MB_PER_TYPE? Am I missing something in
> system configuration and Linux is not supposed to dump those unused
> virtual memory pages? This behavior is expressed on CentOS7, but I
> *think* it was also reproducible on more modern distributions.
>
> Thanks in advance,
> Valerii.