[PATCH 3/4] tracing/osnoise: start_kthread: Always check OSN_WORKLOAD
From: Crystal Wood <hidden>
Date: 2026-08-24 21:16:41
Subsystem:
the rest, tracing, tracing os noise / latency tracers · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
We can get here on timerlat with OSN_WORKLOAD cleared via osnoise_hotplug_workfn(). While we're moving this code, remove the pointless compiler barrier immediately before returning from a function. Even if it's inlined, it's not doing anything useful. Signed-off-by: Crystal Wood <redacted> --- kernel/trace/trace_osnoise.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index a53a07e59197..0f27af6ade3e 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c@@ -2056,16 +2056,17 @@ static int start_kthread(unsigned int cpu) if (osn->kthread) goto out; + /* Can still happen with timerlat via cpu hotplug */ + if (!test_bit(OSN_WORKLOAD, &osnoise_options)) { + if (!timerlat_enabled()) + osn->sampling = true; + goto out; + } + if (timerlat_enabled()) { snprintf(comm, 24, "timerlat/%d", cpu); main = timerlat_main; } else { - /* if no workload, just return */ - if (!test_bit(OSN_WORKLOAD, &osnoise_options)) { - per_cpu(per_cpu_osnoise_var, cpu).sampling = true; - barrier(); - goto out; - } snprintf(comm, 24, "osnoise/%d", cpu); }
--
2.54.0