On Jun 21, 2016 7:55 AM, "Josh Poimboeuf" <[email protected]> wrote: > > On Mon, Jun 20, 2016 at 12:16:22PM -0700, Andy Lutomirski wrote: > > On Mon, Jun 20, 2016 at 11:00 AM, Josh Poimboeuf <[email protected]> > > wrote: > > > > > > > > From: Josh Poimboeuf <[email protected]> > > > Subject: [PATCH] perf: add 'perf bench syscall' > > > > > > Add a basic 'perf bench syscall' benchmark which does a getppid() system > > > call in a tight loop. > > > > > > > My one suggestion would be to use a different syscall than getppid(), > > as getppid() can have unusual performance characteristics on kernels > > with pid namespaces enabled. I'm a fan of prctl(-1, 0, 0, 0, 0). > > Hm, can you elaborate on the unusual performance characteristics of > getppid()? The code seems pretty minimal.
task_this_vnr -> pid_vnr -> pid_nr_ns There's probably something better than prctl, though. --Andy
