The Performance Impact To POWER9's Eager L1d Cache Flushing Fix

One of the areas where there can be a change in performance detected is obviously with I/O performance...

But thankfully in many cases the performance was barely detectable if at all and not as severe as what we have seen with all the Intel CPU mitigations impacting performance.

But still in some cases the new default kernel state for POWER9 will mean slightly lower performance.

For workloads not interacting with the kernel much, the performance should be the same as with prior kernels.