Merge branch 'perf-urgent-for-linus' of git://

Pull perf fixes from Ingo Molnar:
 "Tooling fixes: a 'perf record' deadlock fix plus debuggability fixes"

* 'perf-urgent-for-linus' of git://
  perf top: Show backtrace when handling a SIGSEGV on --stdio mode
  perf tools: Fix buildid processing
  perf tools: Make fork event processing more resilient
  perf tools: Avoid deadlock when map_groups are broken