[PATCH V2] perf tools: Change the default filenames for perf kvm diff to perf.data.xxx and perf.data.xxx.old

Command perf kvm diff is used to diff perf.data.host and perf.data.guest by default currently. But it is not a good default behavior. Example: # perf kvm --guestkallsyms /home/kallsyms --guestmodules /home/modules record -a sleep 1 [ perf record: Woken up 1 times to write data ]

[PATCH V2] perf tools: Change the default filenames for perf kvm diff to perf.data.xxx and perf.data.xxx.old

Command perf kvm diff is used to diff perf.data.host and perf.data.guest by default currently. But it is not a good default behavior. Example: # perf kvm --guestkallsyms /home/kallsyms --guestmodules /home/modules record -a sleep 1 [ perf record: Woken up 1 times to write data ]