[PATCH v2] selftests/ftrace: fix event-no-pid on 1-core machine

[PATCH v2] selftests/ftrace: fix event-no-pid on 1-core machine

[Krzysztof Kozlowski]

When running event-no-pid test on small machines (e.g. cloud 1-core
instance), other events might not happen:

    + cat trace
    + cnt=0
    + [ 0 -eq 0 ]
    + fail No other events were recorded
    [15] event tracing - restricts events based on pid notrace filtering [FAIL]

Schedule a simple sleep task to be sure that some other process events
get recorded.

Fixes: ebed9628f5c2 ("selftests/ftrace: Add test to test new set_event_notrace_pid file")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

---

Changes since v1:
1. Correct spelling in commit msg.
2. Add Steven's ack.
---
 .../testing/selftests/ftrace/test.d/event/event-no-pid.tc  | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
index e6eb78f0b954..9933ed24f901 100644
--- a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
+++ b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
@@ -57,6 +57,10 @@ enable_events() {
     echo 1 > tracing_on
 }
 
+other_task() {
+    sleep .001 || usleep 1 || sleep 1
+}
+
 echo 0 > options/event-fork
 
 do_reset
@@ -94,6 +98,9 @@ child=$!
 echo "child = $child"
 wait $child
 
+# Be sure some other events will happen for small systems (e.g. 1 core)
+other_task
+
 echo 0 > tracing_on
 
 cnt=`count_pid $mypid`
-- 
2.27.0

Re: [PATCH v2] selftests/ftrace: fix event-no-pid on 1-core machine

[Steven Rostedt]

Shuah,

Want to take this in your tree?

-- Steve


On Wed, 23 Jun 2021 15:43:15 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> wrote:

> When running event-no-pid test on small machines (e.g. cloud 1-core
> instance), other events might not happen:
> 
>     + cat trace
>     + cnt=0
>     + [ 0 -eq 0 ]
>     + fail No other events were recorded
>     [15] event tracing - restricts events based on pid notrace filtering [FAIL]
> 
> Schedule a simple sleep task to be sure that some other process events
> get recorded.
> 
> Fixes: ebed9628f5c2 ("selftests/ftrace: Add test to test new set_event_notrace_pid file")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> 
> ---
> 
> Changes since v1:
> 1. Correct spelling in commit msg.
> 2. Add Steven's ack.
> ---
>  .../testing/selftests/ftrace/test.d/event/event-no-pid.tc  | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
> index e6eb78f0b954..9933ed24f901 100644
> --- a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
> +++ b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
> @@ -57,6 +57,10 @@ enable_events() {
>      echo 1 > tracing_on
>  }
>  
> +other_task() {
> +    sleep .001 || usleep 1 || sleep 1
> +}
> +
>  echo 0 > options/event-fork
>  
>  do_reset
> @@ -94,6 +98,9 @@ child=$!
>  echo "child = $child"
>  wait $child
>  
> +# Be sure some other events will happen for small systems (e.g. 1 core)
> +other_task
> +
>  echo 0 > tracing_on
>  
>  cnt=`count_pid $mypid`

Re: [PATCH v2] selftests/ftrace: fix event-no-pid on 1-core machine

[Shuah Khan]

On 6/23/21 7:46 AM, Steven Rostedt wrote:
> Shuah,
> 
> Want to take this in your tree?
> 

Yes. I can pick this up.

thanks,
-- Shuah