From: Daniel Bristot de Oliveira bristot@kernel.org
mainline inclusion from mainline-v5.16-rc1 commit 2bd1bdf01fb25906f18cd8ebfac81c2217d1478a category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4G64B CVE: NA
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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/ee633e82867c5b88851aa6040522a799c0034486.163570289...
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 Signed-off-by: Wang ShaoBo bobo.shaobowang@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 225888c9164b..d6cedd2e039b 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -1655,9 +1655,6 @@ 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 @@ -1702,7 +1699,7 @@ 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); /* @@ -1716,7 +1713,7 @@ 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);