[PATCH] trace: change CPU ring buffer state from tracing_cpumask

[PATCH] trace: change CPU ring buffer state from tracing_cpumask

[Vaibhav Nagarnaik]

According to Documentation/trace/ftrace.txt:

tracing_cpumask:

        This is a mask that lets the user only trace
        on specified CPUS. The format is a hex string
        representing the CPUS.

The tracing_cpumask currently doesn't affect the tracing state of
per-CPU ring buffers.

This patch enables/disables CPU recording as its corresponding bit in
tracing_cpumask is set/unset.

Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
---
 kernel/trace/trace.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e8aa324..d8ed798 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2433,10 +2433,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 		if (cpumask_test_cpu(cpu, tracing_cpumask) &&
 				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
 			atomic_inc(&global_trace.data[cpu]->disabled);
+			ring_buffer_record_disable_cpu(global_trace.buffer, cpu);
 		}
 		if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
 				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
 			atomic_dec(&global_trace.data[cpu]->disabled);
+			ring_buffer_record_enable_cpu(global_trace.buffer, cpu);
 		}
 	}
 	arch_spin_unlock(&ftrace_max_lock);
-- 
1.7.3.1

Re: [PATCH] trace: change CPU ring buffer state from tracing_cpumask

[Vaibhav Nagarnaik]

On Wed, Jul 20, 2011 at 6:04 PM, Vaibhav Nagarnaik
<vnagarnaik@google.com> wrote:
> According to Documentation/trace/ftrace.txt:
>
> tracing_cpumask:
>
>        This is a mask that lets the user only trace
>        on specified CPUS. The format is a hex string
>        representing the CPUS.
>
> The tracing_cpumask currently doesn't affect the tracing state of
> per-CPU ring buffers.
>
> This patch enables/disables CPU recording as its corresponding bit in
> tracing_cpumask is set/unset.
>
> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
> ---
>  kernel/trace/trace.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index e8aa324..d8ed798 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -2433,10 +2433,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
>                if (cpumask_test_cpu(cpu, tracing_cpumask) &&
>                                !cpumask_test_cpu(cpu, tracing_cpumask_new)) {
>                        atomic_inc(&global_trace.data[cpu]->disabled);
> +                       ring_buffer_record_disable_cpu(global_trace.buffer, cpu);
>                }
>                if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
>                                cpumask_test_cpu(cpu, tracing_cpumask_new)) {
>                        atomic_dec(&global_trace.data[cpu]->disabled);
> +                       ring_buffer_record_enable_cpu(global_trace.buffer, cpu);
>                }
>        }
>        arch_spin_unlock(&ftrace_max_lock);

Hi Steve

What do you think about this patch?

Vaibhav Nagarnaik

Re: [PATCH] trace: change CPU ring buffer state from tracing_cpumask

[Steven Rostedt]

On Tue, 2011-08-30 at 18:07 -0700, Vaibhav Nagarnaik wrote:
> >        arch_spin_unlock(&ftrace_max_lock);
> 
> Hi Steve
> 
> What do you think about this patch?

I'm fine with it. I'll see if I can add it to my 3.2 queue. I'm still
looking at some of your other patches you sent.

I'm still in the process of getting back into the swing of things as I
just came back from vacation :)

-- Steve