[PATCH v4] mempool: optimize get objects with constant n

[Thomas Monjalon]

18/04/2023 22:09, Morten Brørup:
> When getting objects from the mempool, the number of objects to get is
> often constant at build time.
> 
> This patch adds another code path for this case, so the compiler can
> optimize more, e.g. unroll the copy loop when the entire request is
> satisfied from the cache.
> 
> On an Intel(R) Xeon(R) E5-2620 v4 CPU, and compiled with gcc 9.4.0,
> mempool_perf_test with constant n shows an increase in rate_persec by an
> average of 17 %, minimum 9.5 %, maximum 24 %.
> 
> The code path where the number of objects to get is unknown at build time
> remains essentially unchanged.
> 
> Signed-off-by: Morten Brørup <mb at smartsharesystems.com>
> Acked-by: Bruce Richardson <bruce.richardson at intel.com>

Applied with suggested added comment, thanks.