[PATCH] doc: describe how kernel inotify support affects tail -f

[Jim Meyering]

While "inotify" is specific to the linux kernel, it is
widespread enough that it's worth mentioning some of the effect
it has on tail -f:

>From acbfebeb8d22a87b76fae32d8d9bf0473e178fdf Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Mon, 23 May 2011 16:09:42 +0200
Subject: [PATCH 1/2] doc: describe how kernel inotify support affects tail -f

* doc/coreutils.texi (tail invocation) [-f]: Mention how inotify
kernel support makes a difference.
Prompted by http://bugzilla.redhat.com/662900
---
 doc/coreutils.texi |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 289c0ba..dfaf4c9 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -2830,6 +2830,11 @@ tail invocation
 Likewise, the @option{-f} option has no effect for any
 operand specified as @samp{-}, when standard input is a FIFO or a pipe.

+With kernel inotify support, output is asynchronous and generally very prompt.
+Otherwise, @command{tail} sleeps for one second between checks---
+use @option{--sleep-interval=@var{N}} to change that default---which can
+make the output appear slightly less responsive or bursty.
+
 @item -F
 @opindex -F
 This option is the same as @option{--follow=name --retry}.  That is, tail
--
1.7.5.2.1.g56b30