3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vaibhav Nagarnaik <vnagarn...@google.com>
commit 71babb2705e2203a64c27ede13ae3508a0d2c16c upstream.
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.
Link:
http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarn...@google.com
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Laurent Chavey <cha...@google.com>
Cc: Justin Teravest <terav...@google.com>
Cc: David Sharp <dhsh...@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarn...@google.com>
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
kernel/trace/trace.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0ed4df0..08a08ba 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2669,10 +2669,12 @@ 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);
--
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