From: Vincent Whitchurch <vincent.whitchurch@axis.com>
To: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>
Cc: <kernel@axis.com>, <tglx@linutronix.de>,
Vincent Whitchurch <vincent.whitchurch@axis.com>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH] tracing: Remove outdated comment in stack handling
Date: Mon, 27 Jul 2020 11:28:40 +0200 [thread overview]
Message-ID: <20200727092840.18659-1-vincent.whitchurch@axis.com> (raw)
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@axis.com>
---
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
next reply other threads:[~2020-07-27 9:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 9:28 Vincent Whitchurch [this message]
2020-07-27 20:52 ` [PATCH] tracing: Remove outdated comment in stack handling Steven Rostedt
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