Commit 2bd1bdf0 authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (VMware)
Browse files

tracing/osnoise: Use start/stop_per_cpu_kthreads() on osnoise_cpus_write() 

When writing a new CPU mask via osnoise/cpus, if the tracer is running,
the workload is restarted to follow the new cpumask. The restart is
currently done using osnoise_workload_start/stop(), which disables the
workload *and* the instrumentation. However, disabling the
instrumentation is not necessary.

Calling start/stop_per_cpu_kthreads() is enough to apply the new
osnoise/cpus config.

Link: https://lkml.kernel.org/r/ee633e82867c5b88851aa6040522a799c0034486.1635702894.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: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 15ca4bdb

kernel/trace/trace_osnoise.c

+2 −5
Original line number Diff line number Diff line
@@ -1678,9 +1678,6 @@ osnoise_cpus_read(struct file *filp, char __user *ubuf, size_t count, 
	return count;

}



static int osnoise_workload_start(void);

static void osnoise_workload_stop(void);



/*

 * osnoise_cpus_write - Write function for "cpus" entry

 * @filp: The active open file structure
@@ -1725,7 +1722,7 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count, 
	mutex_lock(&trace_types_lock);

	running = osnoise_busy;

	if (running)

		osnoise_workload_stop();

		stop_per_cpu_kthreads();



	mutex_lock(&interface_lock);

	/*
@@ -1739,7 +1736,7 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count, 
	mutex_unlock(&interface_lock);



	if (running)

		osnoise_workload_start();

		start_per_cpu_kthreads();

	mutex_unlock(&trace_types_lock);



	free_cpumask_var(osnoise_cpumask_new);