On Fri, Sep 14, 2018 at 01:47:25PM +0200, Jiri Olsa wrote: > On Fri, Sep 14, 2018 at 01:15:28PM +0200, Peter Zijlstra wrote: > > On Fri, Sep 14, 2018 at 11:40:22AM +0200, Ingo Molnar wrote: > > > In fact keeping the files separate has scalability advantages for 'perf > > > report' and similar > > > parsing tools: they could read all the streams in a per-CPU fashion > > > already, from the very > > > beginning. > > > > Also writing to different files from different CPUs is good for record, > > less contention on the inode state (which include pagecache). > > maybe I should explain a little bit more on this > > we write to different (per-cpu) files during the record, > and at the end of the session, we take them and store > them inside perf.data
How long does it take to combine that? If we generated a lot of data, that could take a fair amount of time, no? I feel that record should not mysteriously 'hang' when it is done. It used to do that at some point because of that stupid .debug crap, but acme fixed that I think.
