This series adds kselftest for histogram trigger expressions and is dependent on the series at [1] and can be applied on top of those after dropping the patch 7 in [1].
This version drops the changes to reset_trigger_file().
[1] https://lore.kernel.org/r/20211025200852.3002369-1-kaleshsingh@google.com/
Kalesh Singh (2): tracing/histogram: Document hist trigger variables (v2) tracing/selftests: Add tests for hist trigger expression parsing (v6)
kernel/trace/trace.c | 11 ++++ .../trigger/trigger-hist-expressions.tc | 65 +++++++++++++++++++ 2 files changed, 76 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc
Update the tracefs README to describe how hist trigger variables can be created.
Signed-off-by: Kalesh Singh kaleshsingh@google.com Acked-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add Masami's Acked-by.
kernel/trace/trace.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bc677cd64224..c41b3786401d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5628,6 +5628,7 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=<field1[,field2,...]>\n" + "\t [:<var1>=<field|var_ref|numeric_literal>[,<var2>=...]]\n" "\t [:values=<field1[,field2,...]>]\n" "\t [:sort=<field1[,field2,...]>]\n" "\t [:size=#entries]\n" @@ -5639,6 +5640,16 @@ static const char readme_msg[] = "\t common_timestamp - to record current timestamp\n" "\t common_cpu - to record the CPU the event happened on\n" "\n" + "\t A hist trigger variable can be:\n" + "\t - a reference to a field e.g. x=current_timestamp,\n" + "\t - a reference to another variable e.g. y=$x,\n" + "\t - a numeric literal: e.g. ms_per_sec=1000,\n" + "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n" + "\n" + "\t hist trigger aritmethic expressions support addition(+), subtraction(-),\n" + "\t multiplication(*) and division(/) operators. An operand can be either a\n" + "\t variable reference, field or numeric literal.\n" + "\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" "\t sum called 'hitcount' is incremented. Keys and values\n"
Add tests for the parsing of hist trigger expressions; and to validate expression evaluation.
Signed-off-by: Kalesh Singh kaleshsingh@google.com --- Changes in v6: - Read the expression result from the trigger file, instead of creating a histogram to print the value.
Changes in v5: - Add README pattern to requires tag, per Masami
Changes in v3: - Remove .sym-offset error check tests
Changes in v2: - Add Namhyung's Reviewed-by - Update comment to clarify err_pos in "Too many subexpressions" test
.../trigger/trigger-hist-expressions.tc | 65 +++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc new file mode 100644 index 000000000000..33eb79589b32 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc @@ -0,0 +1,65 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: event trigger - test histogram expression parsing +# requires: set_event events/sched/sched_process_fork/trigger events/sched/sched_process_fork/hist error_log "<var1>=<field|var_ref|numeric_literal>":README + + +fail() { #msg + echo $1 + exit_fail +} + +test_hist_expr() { # test_name expression expected_val + trigger="events/sched/sched_process_fork/trigger" + + reset_trigger_file $trigger + + echo "Test hist trigger expressions - $1" + + echo "hist:keys=common_pid:x=$2" > $trigger + + for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done + + x=`grep -o 'x=[[:digit:]]*' $trigger | awk -F= '{ print $2 }'` + actual=$(( x + 0 )) # To print negative numbers correctly + + if [ $actual != $3 ]; then + fail "Failed hist trigger expression evaluation: Expression: $2 Expected: $3, Actual: $actual" + fi + + reset_trigger_file $trigger +} + +check_error() { # test_name command-with-error-pos-by-^ + trigger="events/sched/sched_process_fork/trigger" + + echo "Test hist trigger expressions - $1" + ftrace_errlog_check 'hist:sched:sched_process_fork' "$2" $trigger +} + +test_hist_expr "Variable assignment" "123" "123" + +test_hist_expr "Subtraction not associative" "16-8-4-2" "2" + +test_hist_expr "Division not associative" "64/8/4/2" "1" + +test_hist_expr "Same precedence operators (+,-) evaluated left to right" "16-8+4+2" "14" + +test_hist_expr "Same precedence operators (*,/) evaluated left to right" "4*3/2*2" "12" + +test_hist_expr "Multiplication evaluated before addition/subtraction" "4+3*2-2" "8" + +test_hist_expr "Division evaluated before addition/subtraction" "4+6/2-2" "5" + +# Division by zero returns -1 +test_hist_expr "Handles division by zero" "3/0" "-1" + +# err pos for "too many subexpressions" is dependent on where +# the last subexpression was detected. This can vary depending +# on how the expression tree was generated. +check_error "Too many subexpressions" 'hist:keys=common_pid:x=32+^10*3/20-4' +check_error "Too many subexpressions" 'hist:keys=common_pid:x=^1+2+3+4+5' + +check_error "Unary minus not supported in subexpression" 'hist:keys=common_pid:x=-(^1)+2' + +exit 0
On Thu, 28 Oct 2021 12:57:58 -0700 Kalesh Singh kaleshsingh@google.com wrote:
Add tests for the parsing of hist trigger expressions; and to validate expression evaluation.
Signed-off-by: Kalesh Singh kaleshsingh@google.com
This looks good to me.
Acked-by: Masami Hiramatsu mhiramat@kernel.org
Thank you!
Changes in v6:
- Read the expression result from the trigger file, instead of creating a histogram to print the value.
Changes in v5:
- Add README pattern to requires tag, per Masami
Changes in v3:
- Remove .sym-offset error check tests
Changes in v2:
- Add Namhyung's Reviewed-by
- Update comment to clarify err_pos in "Too many subexpressions" test
.../trigger/trigger-hist-expressions.tc | 65 +++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc new file mode 100644 index 000000000000..33eb79589b32 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-expressions.tc @@ -0,0 +1,65 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: event trigger - test histogram expression parsing +# requires: set_event events/sched/sched_process_fork/trigger events/sched/sched_process_fork/hist error_log "<var1>=<field|var_ref|numeric_literal>":README
+fail() { #msg
- echo $1
- exit_fail
+}
+test_hist_expr() { # test_name expression expected_val
- trigger="events/sched/sched_process_fork/trigger"
- reset_trigger_file $trigger
- echo "Test hist trigger expressions - $1"
- echo "hist:keys=common_pid:x=$2" > $trigger
- for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
- x=`grep -o 'x=[[:digit:]]*' $trigger | awk -F= '{ print $2 }'`
- actual=$(( x + 0 )) # To print negative numbers correctly
- if [ $actual != $3 ]; then
fail "Failed hist trigger expression evaluation: Expression: $2 Expected: $3, Actual: $actual"- fi
- reset_trigger_file $trigger
+}
+check_error() { # test_name command-with-error-pos-by-^
- trigger="events/sched/sched_process_fork/trigger"
- echo "Test hist trigger expressions - $1"
- ftrace_errlog_check 'hist:sched:sched_process_fork' "$2" $trigger
+}
+test_hist_expr "Variable assignment" "123" "123"
+test_hist_expr "Subtraction not associative" "16-8-4-2" "2"
+test_hist_expr "Division not associative" "64/8/4/2" "1"
+test_hist_expr "Same precedence operators (+,-) evaluated left to right" "16-8+4+2" "14"
+test_hist_expr "Same precedence operators (*,/) evaluated left to right" "4*3/2*2" "12"
+test_hist_expr "Multiplication evaluated before addition/subtraction" "4+3*2-2" "8"
+test_hist_expr "Division evaluated before addition/subtraction" "4+6/2-2" "5"
+# Division by zero returns -1 +test_hist_expr "Handles division by zero" "3/0" "-1"
+# err pos for "too many subexpressions" is dependent on where +# the last subexpression was detected. This can vary depending +# on how the expression tree was generated. +check_error "Too many subexpressions" 'hist:keys=common_pid:x=32+^10*3/20-4' +check_error "Too many subexpressions" 'hist:keys=common_pid:x=^1+2+3+4+5'
+check_error "Unary minus not supported in subexpression" 'hist:keys=common_pid:x=-(^1)+2'
+exit 0
2.33.0.1079.g6e70778dc9-goog
linux-kselftest-mirror@lists.linaro.org
-
Kalesh Singh -
Masami Hiramatsu