* Liang, Kan <kan.li...@intel.com> wrote: > For 'all', do you mean the whole process?
Yeah. > I think that's the ultimate goal. Eventually there will be per-CPU recording > threads created at the beginning of perf record and go through the whole > process. > The plan is to do the multithreading step by step from the simplest case. > Synthesizing stage is just a start. So, why not do it like the kernel did: add all the threads, create the percpu files, and introduce a 'big perf lock' (big mutex) that is taken for all the current non-threaded perf functionality. This should be fairly straightforward to do and should be 'obviously correct'. _Then_ start doing the hard threading work on top of this, like threading the synthesizing phase. Doing the whole per CPU thread setup/teardown for just the synthesizing part of it looks like the wrong design. I.e. what I'm suggesting is no extra threading work, just organizing it in a different fashion and increasing the life-time of the per CPU threads from 'perf startup' to 'perf shutdown'. Thanks, Ingo