[for-next][PATCH 03/14] tracing/osnoise: Split workload start from the tracer start

Steven Rostedt
2021-11-02T20:12:10Z

In preparation from supporting multiple trace instances, create
workload start/stop specific functions.

No functional change.

Link: https://lkml.kernel.org/r/74b090971e9acdd13625be1c28ef3270d2275e77.1635702894.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_osnoise.c | 59 ++++++++++++++++++++++--------------
1 file changed, 36 insertions(+), 23 deletions(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 7d6be609d3dd..5279a4990493 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1546,7 +1546,7 @@ static int start_kthread(unsigned int cpu)
* This starts the kernel thread that will look for osnoise on many
* cpus.
*/
-static int start_per_cpu_kthreads(struct trace_array *tr)
+static int start_per_cpu_kthreads(void)
{
struct cpumask *current_mask = &save_cpumask;
int retval = 0;
@@ -1678,8 +1678,8 @@ osnoise_cpus_read(struct file *filp, char __user *ubuf, size_t count,
return count;
}

-static void osnoise_tracer_start(struct trace_array *tr);
-static void osnoise_tracer_stop(struct trace_array *tr);
+static int osnoise_workload_start(void);
+static void osnoise_workload_stop(void);

/*
* osnoise_cpus_write - Write function for "cpus" entry
@@ -1701,7 +1701,6 @@ static ssize_t
osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,
loff_t *ppos)
{
- struct trace_array *tr = osnoise_trace;
cpumask_var_t osnoise_cpumask_new;
int running, err;
char buf[256];
@@ -1726,7 +1725,7 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,
mutex_lock(&trace_types_lock);
running = osnoise_busy;
if (running)
- osnoise_tracer_stop(tr);
+ osnoise_workload_stop();

mutex_lock(&interface_lock);
/*
@@ -1740,7 +1739,7 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,
mutex_unlock(&interface_lock);

if (running)
- osnoise_tracer_start(tr);
+ osnoise_workload_start();
mutex_unlock(&trace_types_lock);

free_cpumask_var(osnoise_cpumask_new);
@@ -1921,7 +1920,10 @@ static int osnoise_hook_events(void)
return -EINVAL;
}

-static int __osnoise_tracer_start(struct trace_array *tr)
+/*
+ * osnoise_workload_start - start the workload and hook to events
+ */
+static int osnoise_workload_start(void)
{
int retval;

@@ -1938,7 +1940,7 @@ static int __osnoise_tracer_start(struct trace_array *tr)
barrier();
trace_osnoise_callback_enabled = true;

- retval = start_per_cpu_kthreads(tr);
+ retval = start_per_cpu_kthreads();
if (retval) {
unhook_irq_events();
return retval;
@@ -1949,20 +1951,10 @@ static int __osnoise_tracer_start(struct trace_array *tr)
return 0;
}

-static void osnoise_tracer_start(struct trace_array *tr)
-{
- int retval;
-
- if (osnoise_busy)
- return;
-
- retval = __osnoise_tracer_start(tr);
- if (retval)
- pr_err(BANNER "Error starting osnoise tracer\n");
-
-}
-
-static void osnoise_tracer_stop(struct trace_array *tr)
+/*
+ * osnoise_workload_stop - stop the workload and unhook the events
+ */
+static void osnoise_workload_stop(void)
{
if (!osnoise_busy)
return;
@@ -1983,6 +1975,27 @@ static void osnoise_tracer_stop(struct trace_array *tr)
osnoise_busy = false;
}

+static void osnoise_tracer_start(struct trace_array *tr)
+{
+ int retval;
+
+ if (osnoise_busy)
+ return;
+
+ retval = osnoise_workload_start();
+ if (retval)
+ pr_err(BANNER "Error starting osnoise tracer\n");
+
+}
+
+static void osnoise_tracer_stop(struct trace_array *tr)
+{
+ if (!osnoise_busy)
+ return;
+
+ osnoise_workload_stop();
+}
+
static int osnoise_tracer_init(struct trace_array *tr)
{

@@ -2023,7 +2036,7 @@ static void timerlat_tracer_start(struct trace_array *tr)

osnoise_data.timerlat_tracer = 1;

- retval = __osnoise_tracer_start(tr);
+ retval = osnoise_workload_start();
if (retval)
goto out_err;

--
2.33.0