On Fri, 30 Jun 2017 20:50:45 +0200 Denys Vlasenko <[email protected]> wrote:
> On Tue, Jun 27, 2017 at 12:28 PM, Masami Hiramatsu <[email protected]> > wrote: > > Use md5sum so that it takes less time of checking > > trace logs update. Since busybox tail/cat takes too > > long time to read the trace log, this uses md5sum > > to check whether trace log is updated or not. > > > > Signed-off-by: Masami Hiramatsu <[email protected]> > > --- > > .../test.d/ftrace/func_traceonoff_triggers.tc | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git > > a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc > > b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc > > index 9cf3852..7a9ab4f 100644 > > --- > > a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc > > +++ > > b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc > > @@ -103,11 +103,11 @@ if [ $on != "0" ]; then > > fail "Tracing is not off" > > fi > > > > -line1=`cat trace | tail -1` > > +csum1=`md5sum trace` > > sleep $SLEEP_TIME > > -line2=`cat trace | tail -1` > > +csum2=`md5sum trace` > > If you replace that with "tail -1 <trace", this code > in busybox will be used: > > off_t current = lseek(fd, 0, SEEK_END); The trace file is a kernel pseudo file that prevents lseek. Now what you could do is: cat trace > tempfile csum1=`tail -1 <tempfile` But then we need to make sure to clean up the files. -- Steve
