From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhiramat at kernel.org (Masami Hiramatsu) Date: Sat, 25 Aug 2018 10:45:09 +0900 Subject: [PATCH v2 24/32] selftests/ftrace: Add max stack tracer testcase In-Reply-To: <20180824192352.262144f5@gandalf.local.home> References: <153443695002.23257.13628220023468200991.stgit@devbox> <153443763074.23257.4052504725796725062.stgit@devbox> <20180824192352.262144f5@gandalf.local.home> Message-ID: <20180825104509.1b739d5d17d860e453daa0ca@kernel.org> On Fri, 24 Aug 2018 19:23:52 -0400 Steven Rostedt wrote: > On Fri, 17 Aug 2018 01:40:30 +0900 > Masami Hiramatsu wrote: > > > Add a testcase for max stack tracer, which checks basic > > max stack usage tracing and its filter feature. > > > > Signed-off-by: Masami Hiramatsu > > --- > > .../ftrace/test.d/ftrace/func_stack_tracer.tc | 39 ++++++++++++++++++++ > > 1 file changed, 39 insertions(+) > > create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > > > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > new file mode 100644 > > index 000000000000..b414f0e3c646 > > --- /dev/null > > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > @@ -0,0 +1,39 @@ > > +#!/bin/sh > > +# SPDX-License-Identifier: GPL-2.0 > > +# description: ftrace - Max stack tracer > > +# Test the basic function of max-stack usage tracing > > + > > +if [ ! -f stack_trace ]; then > > + echo "Max stack tracer is not supported - please make CONFIG_STACK_TRACER=y" > > + exit_unsupported > > +fi > > + > > +echo > stack_trace_filter > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > + > > +: "Fork and wait for the first entry become !lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" || break; > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > > + > > +echo '*lock*' > stack_trace_filter > > +test `cat stack_trace_filter | wc -l` -eq `grep lock stack_trace_filter | wc -l` > > + > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > This test fails quite a bit because it doesn't guarantee that another > stack trace gets in that is bigger, and we don't find the "lock". Hmm, maybe I misunderstand what is the stack_trace_filter. I thought it filtered the function that triggered stack trace, so the top of stack trace was always filtered function. If not, what does this filter? Thank you, > > -- Steve > > > + > > +: "Fork and always the first entry including lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > -- Masami Hiramatsu From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhiramat@kernel.org (Masami Hiramatsu) Date: Sat, 25 Aug 2018 10:45:09 +0900 Subject: [PATCH v2 24/32] selftests/ftrace: Add max stack tracer testcase In-Reply-To: <20180824192352.262144f5@gandalf.local.home> References: <153443695002.23257.13628220023468200991.stgit@devbox> <153443763074.23257.4052504725796725062.stgit@devbox> <20180824192352.262144f5@gandalf.local.home> Message-ID: <20180825104509.1b739d5d17d860e453daa0ca@kernel.org> Content-Type: text/plain; charset="UTF-8" Message-ID: <20180825014509.FlON5V9mXCDzLqNc1OxiYCZJBNi9kAvk7xfZFI2WbdY@z> On Fri, 24 Aug 2018 19:23:52 -0400 Steven Rostedt wrote: > On Fri, 17 Aug 2018 01:40:30 +0900 > Masami Hiramatsu wrote: > > > Add a testcase for max stack tracer, which checks basic > > max stack usage tracing and its filter feature. > > > > Signed-off-by: Masami Hiramatsu > > --- > > .../ftrace/test.d/ftrace/func_stack_tracer.tc | 39 ++++++++++++++++++++ > > 1 file changed, 39 insertions(+) > > create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > > > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > new file mode 100644 > > index 000000000000..b414f0e3c646 > > --- /dev/null > > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > @@ -0,0 +1,39 @@ > > +#!/bin/sh > > +# SPDX-License-Identifier: GPL-2.0 > > +# description: ftrace - Max stack tracer > > +# Test the basic function of max-stack usage tracing > > + > > +if [ ! -f stack_trace ]; then > > + echo "Max stack tracer is not supported - please make CONFIG_STACK_TRACER=y" > > + exit_unsupported > > +fi > > + > > +echo > stack_trace_filter > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > + > > +: "Fork and wait for the first entry become !lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" || break; > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > > + > > +echo '*lock*' > stack_trace_filter > > +test `cat stack_trace_filter | wc -l` -eq `grep lock stack_trace_filter | wc -l` > > + > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > This test fails quite a bit because it doesn't guarantee that another > stack trace gets in that is bigger, and we don't find the "lock". Hmm, maybe I misunderstand what is the stack_trace_filter. I thought it filtered the function that triggered stack trace, so the top of stack trace was always filtered function. If not, what does this filter? Thank you, > > -- Steve > > > + > > +: "Fork and always the first entry including lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > -- Masami Hiramatsu