diff options
Diffstat (limited to 'meta/recipes-kernel/lttng/lttng-tools/0001-Fix-Tests-race-condition-in-test_event_tracker.patch')
| -rw-r--r-- | meta/recipes-kernel/lttng/lttng-tools/0001-Fix-Tests-race-condition-in-test_event_tracker.patch | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/meta/recipes-kernel/lttng/lttng-tools/0001-Fix-Tests-race-condition-in-test_event_tracker.patch b/meta/recipes-kernel/lttng/lttng-tools/0001-Fix-Tests-race-condition-in-test_event_tracker.patch new file mode 100644 index 0000000000..10020e1ecf --- /dev/null +++ b/meta/recipes-kernel/lttng/lttng-tools/0001-Fix-Tests-race-condition-in-test_event_tracker.patch @@ -0,0 +1,221 @@ +From d3392e4850532c02e53e3c3ff1cc27df7e51c941 Mon Sep 17 00:00:00 2001 +From: Francis Deslauriers <francis.deslauriers@efficios.com> +Date: Tue, 7 Sep 2021 17:10:31 -0400 +Subject: [PATCH 1/2] Fix: Tests: race condition in test_event_tracker +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Background +========== +The `test_event_tracker` file contains test cases when the event +generating app in executed in two distinct steps. Those two steps are +preparation and execution. + 1. the preparation is the launching the app in the background, and + 2. the execution is actually generating the event that should or + should not be traced depending on the test case. + +This is useful to test the tracker feature since we want to ensure that +already running apps are notified properly when changing their tracking +status. + +Issue +===== +The `test_event_vpid_track_untrack` test case suffers from a race +condition that is easy to reproduce on Yocto. + +The issue is that sometimes events are end up the trace when none is +expected. + +This is due to the absence of synchronization point at the launch of the +app which leads to the app being scheduled in-between the track-untrack +calls leading to events being recorded to the trace. + +It's easy to reproduce this issue on my machine by adding a `sleep 5` +between the track and untrack calls and setting the `NR_USEC_WAIT` +variable to 1. + +Fix +=== +Using the testapp `--sync-before-last-event-touch` flag to make the app +create a file when all but the last event are executed. We then have the +app wait until we create a file (`--sync-before-last-event`) to generate +that last event. This way, we are sure no event will be generated when +running the track and untrack commands. + +Notes +===== +- This issue affects other test cases in this file. +- This commit fixes a typo in the test header. +- This commit adds `diag` calls to help tracking to what test the output + relates to when reading the log. + +Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com> +Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com> +Change-Id: Ia2b68128dc9a805526f9748f31ec2c2d95566f31 +Upstream-Status: Backport +Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com> +--- + .../tools/tracker/test_event_tracker | 56 ++++++++++++++----- + 1 file changed, 42 insertions(+), 14 deletions(-) + +diff --git a/tests/regression/tools/tracker/test_event_tracker b/tests/regression/tools/tracker/test_event_tracker +index feb3787..cc0f698 100755 +--- a/tests/regression/tools/tracker/test_event_tracker ++++ b/tests/regression/tools/tracker/test_event_tracker +@@ -5,7 +5,7 @@ + # + # SPDX-License-Identifier: GPL-2.0-only + +-TEST_DESC="LTTng - Event traker test" ++TEST_DESC="LTTng - Event tracker test" + + CURDIR=$(dirname "$0")/ + TESTDIR="$CURDIR/../../.." +@@ -15,7 +15,7 @@ TESTAPP_KERNEL_NAME="gen-kernel-test-events" + TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME" + TESTAPP_KERNEL_BIN="$TESTAPP_PATH/$TESTAPP_KERNEL_NAME/$TESTAPP_KERNEL_NAME" + SESSION_NAME="tracker" +-NR_ITER=100 ++NR_ITER=1 + NUM_GLOBAL_TESTS=2 + NUM_UST_TESTS=283 + NUM_KERNEL_TESTS=462 +@@ -30,27 +30,41 @@ SCRIPT_GROUPNAME="$(id -gn)" + + CHILD_PID=-1 + WAIT_PATH= +-AFTER_FIRST_PATH= +-BEFORE_LAST_PATH= ++TOUCH_BEFORE_LAST_PATH= ++SYNC_BEFORE_LAST_PATH= + + source $TESTDIR/utils/utils.sh + ++# Launch the testapp and execute it up until right before the last event. It is ++# useful to do it in two seperate steps in order to test tracking and ++# untracking on an active app. + function prepare_ust_app + { +- AFTER_FIRST_PATH=$(mktemp --tmpdir -u tmp.${FUNCNAME[0]}_sync_after_first.XXXXXX) +- BEFORE_LAST_PATH=$(mktemp --tmpdir -u tmp.${FUNCNAME[0]}_sync_before_last.XXXXXX) ++ TOUCH_BEFORE_LAST_PATH=$(mktemp --tmpdir -u tmp.${FUNCNAME[0]}_touch_before_last.XXXXXX) ++ SYNC_BEFORE_LAST_PATH=$(mktemp --tmpdir -u tmp.${FUNCNAME[0]}_sync_before_last.XXXXXX) ++ ++ $TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT \ ++ --sync-before-last-event-touch "$TOUCH_BEFORE_LAST_PATH" \ ++ --sync-before-last-event "$SYNC_BEFORE_LAST_PATH" & + +- $TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT -a "$AFTER_FIRST_PATH" -b "$BEFORE_LAST_PATH" & + CHILD_PID=$! ++ ++ # Wait for the app to execute all the way to right before the last ++ # event. ++ while [ ! -f "${TOUCH_BEFORE_LAST_PATH}" ]; do ++ sleep 0.5 ++ done + } + ++# Generate the last event. + function trace_ust_app + { +- touch "$BEFORE_LAST_PATH" +- wait ++ # Ask the test app to generate the last event. ++ touch "$SYNC_BEFORE_LAST_PATH" ++ wait "$CHILD_PID" + ok $? "Traced application stopped." +- rm "$BEFORE_LAST_PATH" +- rm "$AFTER_FIRST_PATH" ++ rm "$SYNC_BEFORE_LAST_PATH" ++ rm "$TOUCH_BEFORE_LAST_PATH" + } + + function prepare_kernel_app +@@ -64,7 +78,7 @@ function prepare_kernel_app + function trace_kernel_app + { + touch "$WAIT_PATH" +- wait ++ wait "$CHILD_PID" + ok $? "Traced application stopped." + rm "$WAIT_PATH" + } +@@ -78,6 +92,8 @@ function test_event_tracker() + local tracker="$4" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -117,6 +133,8 @@ function test_event_vpid_tracker() + local wildcard="$3" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -160,6 +178,8 @@ function test_event_pid_tracker() + local wildcard="$3" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -203,6 +223,8 @@ function test_event_tracker_fail() + local wildcard="$2" + local tracker="$3" + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -222,6 +244,8 @@ function test_event_track_untrack() + local tracker="$4" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -262,6 +286,8 @@ function test_event_vpid_track_untrack() + local wildcard="$3" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -302,6 +328,8 @@ function test_event_pid_track_untrack() + local wildcard="$3" + local channel='' + ++ diag "${FUNCNAME[0]} $*" ++ + trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" +@@ -336,9 +364,9 @@ function test_event_pid_track_untrack() + + function test_event_ust_vpid_untrack_snapshot() + { +- local trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) ++ diag "${FUNCNAME[0]} $*" + +- diag "Test_event_ust_vpid_untrack_snapshot" ++ local trace_path=$(mktemp --tmpdir -d tmp.${FUNCNAME[0]}_trace_path.XXXXXX) + + create_lttng_session_ok $SESSION_NAME "$trace_path" "--snapshot" + +-- +2.20.1 + |