From ee896ee8051a618ea4fe3d91c58d3e6ef9faf705 Mon Sep 17 00:00:00 2001
From: Vincent Whitchurch <vincent.whitchurch@axis.com>
Date: Mon, 27 Jul 2020 11:28:40 +0200
Subject: [PATCH] tracing: Remove outdated comment in stack handling
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.)
Link: https://lkml.kernel.org/r/20200727092840.18659-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4aab712f9567..dbcacdd56b02 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2930,12 +2930,6 @@ 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;