Hi Steve, On Mon, Mar 30, 2015 at 05:15:11PM -0400, Steven Rostedt wrote: > On Thu, 26 Mar 2015 09:32:23 +0900 > Namhyung Kim <namhy...@kernel.org> wrote: > > > The usleep is only provided on distros from Redhat so running ftracetest > > on other distro resulted in failures due to the missing usleep. > > > > The reason of using [u]sleep in the test was to generate (scheduler) > > events. But as we use 'cat trace | grep | wc -l' to read the events, > > the command themselves already generate some events before reading the > > trace file so no need to call [u]sleep explicitly. > > Note, opening "trace" via cat stops tracing. There is a possible race > where the cat will not produce events. My worry is that if the shell > implements its own "cat" command, it may not fork, and open the trace > file. Which would not have any events in it, and opening it will > disable the rest of the command from having events.
I understand your point. But this is not just cat, it needs grep and wc also. So I think there should be scheduler event(s). > > What about using: > > ping localhost -c 1 > > ? I'm okay with ping though but worried if some tiny system might lack the ping command.. Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/