On 02.05.2024 18:55, Carlo Nonato wrote: > From: Luca Miccio <lucmic...@gmail.com> > > Add a new command line parameter to configure Xen cache colors. > These colors are dumped together with other coloring info. > > Benchmarking the VM interrupt response time provides an estimation of > LLC usage by Xen's most latency-critical runtime task. Results on Arm > Cortex-A53 on Xilinx Zynq UltraScale+ XCZU9EG show that one color, which > reserves 64 KiB of L2, is enough to attain best responsiveness: > - Xen 1 color latency: 3.1 us > - Xen 2 color latency: 3.1 us > > Since this is the most common target for Arm cache coloring, the default > amount of Xen colors is set to one. > > More colors are instead very likely to be needed on processors whose L1 > cache is physically-indexed and physically-tagged, such as Cortex-A57. > In such cases, coloring applies to L1 also, and there typically are two > distinct L1-colors. Therefore, reserving only one color for Xen would > senselessly partitions a cache memory that is already private, i.e. > underutilize it. > > Signed-off-by: Luca Miccio <lucmic...@gmail.com> > Signed-off-by: Marco Solieri <marco.soli...@minervasys.tech> > Signed-off-by: Carlo Nonato <carlo.non...@minervasys.tech>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
