From 0ca6d12c9768ee15e6c7d65ddb5cb35c05946e1e Mon Sep 17 00:00:00 2001 From: Kalesh Singh <kaleshsingh@google.com> Date: Fri, 29 Oct 2021 11:33:28 -0700 Subject: [PATCH] tracing/histogram: Update division by 0 documentation 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@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.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 66ec972dfb780..859fd1b76c638 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:: -- GitLab