Re: [PATCH v4] eal: allow worker lcore stacks to be allocated from hugepage memory

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 17 May 2022 11:31:36 -0400
Don Wallwork <donw@xsightlabs.com> wrote:

> Add support for using hugepages for worker lcore stack memory.  The
> intent is to improve performance by reducing stack memory related TLB
> misses and also by using memory local to the NUMA node of each lcore.
> 
> EAL option '--huge-worker-stack [stack-size-in-kbytes]' is added to allow
> the feature to be enabled at runtime.  If the size is not specified,
> the system pthread stack size will be used.
> 
> Signed-off-by: Don Wallwork <donw@xsightlabs.com>
> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> ---

This looks great, just thinking a little more about what the impact
of using it would be.

Since the memory region for the stack is never freed, it will cause
complaints from address sanitizer and maybe from valgrind.

One way to workaround that would be to use the lower level allocation
routine to get the memory segments. This would make stacks a multiple
of page size which would not be bad idea anyway. 
Plus you could use eal_memalloc_seg_bulk.