The patch below does not apply to the 3.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 099ed151675cd1d2dbeae1dac697975f6a68716d Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> Date: Tue, 24 Jun 2014 23:50:09 -0400 Subject: [PATCH] tracing: Remove ftrace_stop/start() from reading the trace file Disabling reading and writing to the trace file should not be able to disable all function tracing callbacks. There's other users today (like kprobes and perf). Reading a trace file should not stop those from happening. Cc: stable@xxxxxxxxxxxxxxx # 3.0+ Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 384ede311717..f243444a3772 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1396,7 +1396,6 @@ void tracing_start(void) arch_spin_unlock(&global_trace.max_lock); - ftrace_start(); out: raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); } @@ -1443,7 +1442,6 @@ void tracing_stop(void) struct ring_buffer *buffer; unsigned long flags; - ftrace_stop(); raw_spin_lock_irqsave(&global_trace.start_lock, flags); if (global_trace.stop_count++) goto out; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html