linux-kernel - [for-next][PATCH 11/14] tracing/histogram: Update division by 0 documentation

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Message-ID: <20211102201158.577975229@goodmis.org>
Date:   Tue, 02 Nov 2021 16:11:37 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     linux-kernel@...r.kernel.org
Cc:     Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Jonathan Corbet <corbet@....net>,
        Ingo Molnar <mingo@...hat.com>, Shuah Khan <shuah@...nel.org>,
        Tom Zanussi <zanussi@...nel.org>,
        Kalesh Singh <kaleshsingh@...gle.com>
Subject: [for-next][PATCH 11/14] tracing/histogram: Update division by 0 documentation

From: Kalesh Singh <kaleshsingh@...gle.com>

If the divisor is a constant and zero, the undeifned case can be
detected and an error returned instead of -1.

Link: https://lkml.kernel.org/r/20211029183339.3216491-3-kaleshsingh@google.com

Cc: Jonathan Corbet <corbet@....net>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Shuah Khan <shuah@...nel.org>
Cc: Tom Zanussi <zanussi@...nel.org>
Signed-off-by: Kalesh Singh <kaleshsingh@...gle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
---
 Documentation/trace/histogram.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 66ec972dfb78..859fd1b76c63 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1766,7 +1766,8 @@ using the same key and variable from yet another event::
 Expressions support the use of addition, subtraction, multiplication and
 division operators (+-\*/).
 
-Note that division by zero always returns -1.
+Note if division by zero cannot be detected at parse time (i.e. the
+divisor is not a constant), the result will be -1.
 
 Numeric constants can also be used directly in an expression::
 
-- 
2.33.0