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>
This commit is contained in:
Kalesh Singh 2021-10-29 11:33:28 -07:00 committed by Steven Rostedt (VMware)
parent 8b5d46fd7a
commit 0ca6d12c97
1 changed files with 2 additions and 1 deletions

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@ -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::