Performance

configname: CONFIG_PCIE_BUS_PERFORMANCE

PCI Express hierarchy optimization setting
└─>PCI support
└─>Performance
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Use MPS and MRRS for best performance. Ensure that a given
device's MPS is no larger than its parent MPS, which allows us to
keep all switches/bridges to the max MPS supported by their
parent. This is the same as booting with 'pci=pcie_bus_perf'.

depends
CONFIG_PCI