From: Dmitry Safonov <0x7f454c46@gmail.com> Since the ring buffer is lockless, there is no need to disable ftrace on CPU. And no one doing so: after commit 68179686ac67cb ("tracing: Remove ftrace_disable/enable_cpu()") ftrace_cpu_disabled stays the same after initialization, nothing changes it. ftrace_cpu_disabled shouldn't be used by any external module since it disables only function and graph_function tracers but not any other tracer. Link: http://lkml.kernel.org/r/1446836846-22239-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 ------ kernel/trace/trace.h | 1 - kernel/trace/trace_functions_graph.c | 6 ------ 3 files changed, 13 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 08af79c106e1..b11582618991 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -100,8 +100,6 @@ static DEFINE_PER_CPU(bool, trace_cmdline_save); */ static int tracing_disabled = 1; -DEFINE_PER_CPU(int, ftrace_cpu_disabled); - cpumask_var_t __read_mostly tracing_buffer_mask; /* @@ -1775,10 +1773,6 @@ trace_function(struct trace_array *tr, struct ring_buffer_event *event; struct ftrace_entry *entry; - /* If we are reading the ring buffer, don't trace */ - if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) - return; - event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), flags, pc); if (!event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index dd7620802e72..919d9d07686f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -667,7 +667,6 @@ extern int DYN_FTRACE_TEST_NAME2(void); extern bool ring_buffer_expanded; extern bool tracing_selftest_disabled; -DECLARE_PER_CPU(int, ftrace_cpu_disabled); #ifdef CONFIG_FTRACE_STARTUP_TEST extern int trace_selftest_startup_function(struct tracer *trace, diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 92382af7a213..a663cbb84107 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -288,9 +288,6 @@ int __trace_graph_entry(struct trace_array *tr, struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ftrace_graph_ent_entry *entry; - if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) - return 0; - event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT, sizeof(*entry), flags, pc); if (!event) @@ -403,9 +400,6 @@ void __trace_graph_return(struct trace_array *tr, struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ftrace_graph_ret_entry *entry; - if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) - return; - event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET, sizeof(*entry), flags, pc); if (!event) -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/