Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V3 0/6] event synthesization multithreading for perf record | Date | Tue, 24 Oct 2017 12:47:49 +0000 |
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> On Tue, Oct 24, 2017 at 11:22:00AM +0200, Ingo Molnar wrote: > > > > * Liang, Kan <kan.liang@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'. > > I recently made some changes on threaded record, which are based on > Namhyungs time* API, which is needed to read/sort the data afterwards > > but I wasn't able to get any substantial and constant reduce of LOST events > and then I got sidetracked and did not finish, but it's in here: > > git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git perf/data > > I'll try to rebase and send it out for comments >
I think I will wait for your patches, and rebase this series. :)
Thanks, Kan
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