tracing/osnoise: Fix notify new tracing_max_latency

commit d3cba7f02cd82118c32651c73374d8a5a459d9a6 upstream.

osnoise/timerlat tracers are reporting new max latency on instances
where the tracing is off, creating inconsistencies between the max
reported values in the trace and in the tracing_max_latency. Thus
only report new tracing_max_latency on active tracing instances.

Link: https://lkml.kernel.org/r/ecd109fde4a0c24ab0f00ba1e9a144ac19a91322.1680104184.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index c732287f5e302048788795875016926b45bf0bd0..2a1b337ac6434c849884a32dfdc663f33466ae98 100644 (file)
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1296,7 +1296,7 @@ static void notify_new_max_latency(u64 latency)
        rcu_read_lock();
        list_for_each_entry_rcu(inst, &osnoise_instances, list) {
                tr = inst->tr;
-               if (tr->max_latency < latency) {
+               if (tracer_tracing_is_on(tr) && tr->max_latency < latency) {
                        tr->max_latency = latency;
                        latency_fsnotify(tr);
                }