[dpdk-dev] Reg 6Wind fastpath DPDK 18.11.1 virtual memory allocation ( 54.5GB of anonymous mapping)

[David Marchand]

On Wed, Jun 9, 2021 at 2:02 PM Shanmugasundaram M <shansirtt at gmail.com> wrote:
> We are using  6Wind fastpath(fp-rte) which is using DPDK version 18.11.1.
> We are seeing  65.5G(preallocated during startup) of virtual memory for
> fp-rte on a 32GB machine, 10G of that was huge pages (5000 mappings of 2M.)
>
> We found 4 strange anon (4K size) segments totaling 54.5G (16+16+16+6.5).
> Note: we changed / customized memory CONFIG_RTE_MAX_MEMSEG_PER_LIST=24576
> and default value of  CONFIG_RTE_MAX_MEMSEG_LISTS=64 used.
> Kindly let us know
> 1. Why are allocating  54.5 GB anonymous mapping
> 2. When will we use it ?

This is likely pre-reserved virtual memory from the DPDK allocator.
This virtual memory won't probably never be used.

But you'd better ask 6WIND guys as they maintain their own DPDK downstream.

Copying a few guys.

-- 
David Marchand