Recently I was asked to look into an issue related to QEMU's I/O subsystem performance - specifically, I was looking for differences in performance between glibc's malloc and other malloc implementations'. After a good deal of benchmarking I was unable to see a clear difference between our malloc (glibc) and others, not because the implementations were similar, but because there was too much noise in the system; the benchmarks were being polluted by other things, not just in QEMU, but...
