[tip:timers/core] Checkpatch: Warn about unexpectedly long msleep's

[tip-bot for Patrick Pannuto <ppannuto@codeaurora.org>]

Commit-ID:  d76db7e68cb9a886056a92c3f0fef56af5ca5ee8
Gitweb:     http://git.kernel.org/tip/d76db7e68cb9a886056a92c3f0fef56af5ca5ee8
Author:     Patrick Pannuto <ppannuto@codeaurora.org>
AuthorDate: Mon, 2 Aug 2010 15:01:07 -0700
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 4 Aug 2010 11:00:45 +0200

Checkpatch: Warn about unexpectedly long msleep's

As explained in Documentation/timers/timers-howto.txt, msleep's
of < 20ms may sleep for as long as 20ms. Caller's of
msleep(1) or msleep(2), etc are likely not to expect this
quirky behavior - warn them.

Signed-off-by: Patrick Pannuto <ppannuto@codeaurora.org>
Cc: apw@canonical.com
Cc: corbet@lwn.net
Cc: arjan@linux.intel.com
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1280786467-26999-5-git-send-email-ppannuto@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 scripts/checkpatch.pl |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 1698c63..8536c33 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2578,6 +2578,13 @@ sub process {
 			}
 		}
 
+# warn about unexpectedly long msleep's
+		if ($line =~ /\bmsleep\s*\((\d+)\);/) {
+			if ($1 < 20) {
+				WARN("msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt\n" . $line);
+			}
+		}
+
 # warn about #ifdefs in C files
 #		if ($line =~ /^.\s*\#\s*if(|n)def/ && ($realfile =~ /\.c$/)) {
 #			print "#ifdef in C files should be avoided\n";