[PATCH] tracing: Remove outdated comment in stack handling

From: Vincent Whitchurch
Date: Mon Jul 27 2020 - 05:28:59 EST


This comment describes the behaviour before commit 2a820bf74918
("tracing: Use percpu stack trace buffer more intelligently"). Since
that commit, interrupts and NMIs do use the per-cpu stacks so the
comment is no longer correct. Remove it.

(Note that the FTRACE_STACK_SIZE mentioned in the comment has never
existed, it probably should have said FTRACE_STACK_ENTRIES.)

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
---
kernel/trace/trace.c | 6 ------
1 file changed, 6 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bb62269724d5..0a0fd197888c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2932,12 +2932,6 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
skip++;
#endif

- /*
- * Since events can happen in NMIs there's no safe way to
- * use the per cpu ftrace_stacks. We reserve it and if an interrupt
- * or NMI comes in, it will just have to use the default
- * FTRACE_STACK_SIZE.
- */
preempt_disable_notrace();

stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1;
--
2.25.1