Hi... On Sat, Mar 9, 2013 at 4:04 PM, Kevin Wilson <wkevils@gmail.com> wrote:
Hi, I have two x86_64 machines: On the first there is Fedora 18 (x86_64); on the second there is Ubunutu 12.10 (server, 64 bit).
I run cat /proc/interrupts on both machines; in both cases, I run this command after an hour when the machine is up. I get: On the fedora machine cat /proc/interrupts | grep TLB TLB: 0 0 TLB shootdowns On the Ubuntu machine, however, there are many TLB shootdowns, on both cores.
That is a very interesting data.... btw, after quick check at http://stackoverflow.com/questions/3748384/what-is-tlb-shootdown, I conclude that likely Fedora 18 default kernel does something, that in your workload prevent tlb shootdown. What can that be? IMHO, one high possibility is preventing process rescheduling to another core(s) and/or grouping all threads in same group in same core(s). But I am not sure. That sounds like defeating the purpose of SMP. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com