From 2bd1bdf01fb25906f18cd8ebfac81c2217d1478a Mon Sep 17 00:00:00 2001 From: Daniel Bristot de Oliveira Date: Sun, 31 Oct 2021 19:04:59 +0100 Subject: [PATCH] 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 Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: John Kacur Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira 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 Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_osnoise.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 5279a4990493..cacc11b7d5ae 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -1678,9 +1678,6 @@ out_unlock: 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);