On Tue, 9 Jul 2024 12:16:34 +0200 Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > On Tue, Jul 09, 2024 at 12:01:03PM +0200, Jiri Olsa wrote: > > On Tue, Jul 09, 2024 at 11:03:04AM +0200, Peter Zijlstra wrote: > > > On Mon, Jul 08, 2024 at 05:25:14PM -0700, Andrii Nakryiko wrote: > > > > > > > Ramping this up to 16 threads shows that mmap_rwsem is getting more > > > > costly, up to 45% of CPU. SRCU is also growing a bit slower to 19% of > > > > CPU. Is this expected? (I'm not familiar with the implementation > > > > details) > > > > > > SRCU getting more expensive is a bit unexpected, it's just a per-cpu > > > inc/dec and a full barrier. > > > > > > > P.S. Would you be able to rebase your patches on top of latest > > > > probes/for-next, which include Jiri's sys_uretprobe changes. Right now > > > > uretprobe benchmarks are quite unrepresentative because of that. > > > > > > What branch is that? kernel/events/ stuff usually goes through tip, no? > > > > it went through the trace tree: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git probes/for-next > > > > and it's in linux-next/master already > > FFS :-/ That touches all sorts and doesn't have any perf ack on. Masami > what gives? This is managing *probes and related dynamic trace-events. Those has been moved from tip. Could you also add linux-trace-kernel@vger ML to CC? Thank you, -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
