[for-linus][PATCH 5/6] tracing/osnoise: Fix notify new tracing_max_latency

From: Steven Rostedt
Date: Mon Apr 03 2023 - 17:23:04 EST


From: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>

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@xxxxxxxxxx

Cc: stable@xxxxxxxxxxxxxxx
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_osnoise.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index e8116094bed8..4496975f2029 100644
--- 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);
}
--
2.39.2