On Tue, Oct 24, 2017 at 02:59:44PM +0200, Ingo Molnar wrote: > > * Jiri Olsa <jo...@redhat.com> wrote: > > > 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: > > So, in the context of system-wide profiling, the way that would work best I > think > is the following: > > thread #0 binds itself to CPU#0 (via sched_setaffinity) and creates a > per-CPU event on CPU#0 > thread #1 binds itself to CPU#1 (via sched_setaffinity) and creates a > per-CPU event on CPU#1 > thread #2 binds itself to CPU#2 (via sched_setaffinity) and creates a > per-CPU event on CPU#2 > > etc. > > Is this how you implemented it?
in a way ;-) but I made it more generic and let record create just few threads and let them share cpu subset.. and so there was no binding > > If the threads in the thread pool are just free-running then the scheduler > might > not migrate it to the 'right' CPU that is streaming the perf events and there > will > be a lot of cross-talking between CPUs. ok it's easy to add binding now and 1:1 thread:cpu mapping.. I'll retry jirka
