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tracing/hwlat: Honor the tracing_cpumask

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commit 96b4833b6827a62c295b149213c68b559514c929 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kevin Hao 2020-07-30 16:23:18 +08:00 committed by Greg Kroah-Hartman
parent 1424f0aa18
commit bd23940da2
1 changed files with 3 additions and 2 deletions
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5
kernel/trace/trace_hwlat.c
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@ -270,6 +270,7 @@ 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)
@ -283,7 +284,7 @@ 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();
@ -360,7 +361,7 @@ static int start_kthread(struct trace_array *tr)
/* Just pick the first CPU on first iteration */
current_mask = &save_cpumask;
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);