Marcelo Pugliesi <mpugliesi2@xxxxxxxxxxxx> writes: > Well, I'm compiling the kernel 2.6.34 or 2.6.36 for Ubuntu 10.10 64bits. I have > a core i7 860 processor, accessing the menuconfig, right at processor family, if > I check the family Core2/Xeon I have less performance from my kernel than if I > use the option Pentium 4! No matter if I use the GCC version 4.4.4 or 4.5.1! > My question then is simple, Why I have a superior performance when using Pentium > 4 architecture if the GCC documentation tells me I should use the Core2/Xeon for > a better result? I don't know what the kernel build does. What do the actual command lines look like (I think you can see them via make V=1). Specifically, which of the -march, -mtune, and -mcpu options does the kernel set? How are you measuring kernel performance? All compiler tuning is only heuristic in nature, so it is possible that the kernel is failing the heuristics in some way. Ian
