From: Kevin Hao haokexin@gmail.com
In calculation of the cpu mask for the hwlat kernel thread, the wrong cpu mask is used instead of the tracing_cpumask, this causes the tracing/tracing_cpumask useless for hwlat tracer. Fixes it.
Link: https://lkml.kernel.org/r/20200730082318.42584-2-haokexin@gmail.com
Cc: Ingo Molnar mingo@redhat.com Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Kevin Hao haokexin@gmail.com Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- kernel/trace/trace_hwlat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index ddb528a6cd51..17873e5d0353 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -283,6 +283,7 @@ static bool disable_migrate; static void move_to_next_cpu(void) { struct cpumask *current_mask = &save_cpumask; + struct trace_array *tr = hwlat_trace; int next_cpu;
if (disable_migrate) @@ -296,7 +297,7 @@ static void move_to_next_cpu(void) goto disable;
get_online_cpus(); - cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask); + cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask); next_cpu = cpumask_next(smp_processor_id(), current_mask); put_online_cpus();
@@ -372,7 +373,7 @@ static int start_kthread(struct trace_array *tr)
/* Just pick the first CPU on first iteration */ get_online_cpus(); - cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask); + cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask); put_online_cpus(); next_cpu = cpumask_first(current_mask);