From: Michael Jeanson <mjeanson@efficios.com>
Date: Tue, 11 Feb 2020 20:35:11 +0000 (-0500)
Subject: fix: workqueue: add worker function to workqueue_execute_end tracepoint (v5.6)
X-Git-Tag: v2.12.0-rc2~3
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=61480a4b07f7269e380967d05738b0e003d11e66;p=lttng-modules.git

fix: workqueue: add worker function to workqueue_execute_end tracepoint (v5.6)

See upstream commit :

  commit 1c5da0ec7f20dfb56030fb93f7f52f48e12deb52
  Author: Daniel Jordan <daniel.m.jordan@oracle.com>
  Date:   Mon Jan 13 17:52:39 2020 -0500

    workqueue: add worker function to workqueue_execute_end tracepoint

    It's surprising that workqueue_execute_end includes only the work when
    its counterpart workqueue_execute_start has both the work and the worker
    function.

    You can't set a tracing filter or trigger based on the function, and
    postprocessing scripts interested in specific functions are harder to
    write since they have to remember the work from _start and match it up
    with the same field in _end.

    Add the function name, taking care to use the copy stashed in the
    worker since the work is no longer safe to touch.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/instrumentation/events/lttng-module/workqueue.h b/instrumentation/events/lttng-module/workqueue.h
index e0ef9178..5e269e30 100644
--- a/instrumentation/events/lttng-module/workqueue.h
+++ b/instrumentation/events/lttng-module/workqueue.h
@@ -92,6 +92,26 @@ LTTNG_TRACEPOINT_EVENT(workqueue_execute_start,
 	)
 )
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
+/**
+ * workqueue_execute_end - called immediately after the workqueue callback
+ * @work:	pointer to struct work_struct
+ * @function:	pointer to worker function
+ *
+ * Allows to track workqueue execution.
+ */
+LTTNG_TRACEPOINT_EVENT(workqueue_execute_end,
+
+	TP_PROTO(struct work_struct *work, work_func_t function),
+
+	TP_ARGS(work, function),
+
+	TP_FIELDS(
+		ctf_integer_hex(void *, work, work)
+		ctf_integer_hex(void *, function, function)
+	)
+)
+#else
 /**
  * workqueue_execute_end - called immediately after the workqueue callback
  * @work:	pointer to struct work_struct
@@ -104,6 +124,7 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE(workqueue_work, workqueue_execute_end,
 
 	TP_ARGS(work)
 )
+#endif
 
 #endif /*  LTTNG_TRACE_WORKQUEUE_H */