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 <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Aug 10, 2010 · 09ef872 · 09ef872
1 parent 1a15a25
commit 09ef872
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
@@ -2592,6 +2592,13 @@ 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";