Re: [PATCH v2 1/3] checkpatch.pl: add missing memory barriers

On Sun, Jan 10, 2016 at 07:07:05AM -0800, Joe Perches wrote:

On Sun, 2016-01-10 at 13:56 +0200, Michael S. Tsirkin wrote:

quoted

SMP-only barriers were missing in checkpatch.pl

Refactor code slightly to make adding more variants easier.

[]

quoted

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl

[]

quoted

@@ -5116,7 +5116,25 @@ sub process {

 			}
 		}
 # check for memory barriers without a comment.
-		if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
+
+		my $barriers = qr{
+			mb|
+			rmb|
+			wmb|
+			read_barrier_depends
+		}x;
+		my $smp_barriers = qr{
+			store_release|
+			load_acquire|
+			store_mb|
+			($barriers)
+		}x;

If I use a variable called $smp_barriers, I'd expect
it to actually be the smp_barriers, not to have to
prefix it with smp_ before using it.

		my $smp_barriers = qr{
			smp_store_release|
			smp_load_acquire|
			smp_store_mb|
			smp_read_barrier_depends
		}x;

or

		my $smp_barriers = qr{
			smp_(?:store_release|load_acquire|store_mb|read_barrier_depends)
		}x;

Yes but virt barriers (added in patch 3) are same things but prefixed
with virt_.  So we need the stems without smp_ prefix. If smp_barriers is
too confusing we'll just need to give them some other name.
How about:
my $smp_barrier_stems

?

quoted

+		my $all_barriers = qr{
+			$barriers|
+			smp_($smp_barriers)
+		}x;

And this shouldn't have a capture group.

		my $all_barriers = qr{
			$barriers|
			$smp_barriers
		}x;		

quoted

+
+		if ($line =~ /\b($all_barriers)\s*\(/) {

This doesn't need the capture group either (?:all_barriers)

quoted

 			if (!ctx_has_comment($first_line, $linenr))
{
 				WARN("MEMORY_BARRIER",
 				     "memory barrier without
comment\n" . $herecurr);