From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joe Perches <joe@perches.com>
Date: Mon, 04 Jan 2016 16:07:40 +0000
Subject: Re: [PATCH 1/3] checkpatch.pl: add missing memory barriers
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To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org
Cc: "Cc : Andy Whitcroft" <apw@canonical.com>, Peter Zijlstra <peterz@infradead.org>, Arnd Bergmann <arnd@arndb.de>, linux-arch@vger.kernel.org, Andrew Cooper <andrew.cooper3@citrix.com>, virtualization@lists.linux-foundation.org, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>, David Miller <davem@davemloft.net>, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Ingo Molnar <mingo@kernel.org>, Tony Lindgren <tony@atomide>

On Mon, 2016-01-04 at 13:36 +0200, Michael S. Tsirkin wrote:
> SMP-only barriers were missing in checkpatch.pl
>=20
> Refactor code slightly to make adding more variants easier.
>=20
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> =A0scripts/checkpatch.pl | 9 ++++++++-
> =A01 file changed, 8 insertions(+), 1 deletion(-)
>=20
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 2b3c228..0245bbe 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -5116,7 +5116,14 @@ sub process {
> =A0			}
> =A0		}
> =A0# check for memory barriers without a comment.
> -		if ($line =3D~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_=
wmb|smp_read_barrier_depends)\(/) {
> +
> +		my @barriers =3D ('mb', 'rmb', 'wmb', 'read_barrier_depends');
> +		my @smp_barriers =3D ('smp_store_release', 'smp_load_acquire', 'smp_st=
ore_mb');
> +
> +		@smp_barriers =3D (@smp_barriers, map {"smp_" . $_} @barriers);

I think using map, which so far checkpatch doesn't use,
makes smp_barriers harder to understand and it'd be
better to enumerate them.

> +		my $all_barriers =3D join('|', (@barriers, @smp_barriers));
> +
> +		if ($line =3D~ /\b($all_barriers)\(/) {

It would be better to use /\b$all_barriers\s*\(/
as there's no reason for the capture and there
could be a space between the function and the
open parenthesis.


> =A0			if (!ctx_has_comment($first_line, $linenr)) {
> =A0				WARN("MEMORY_BARRIER",
> =A0				=A0=A0=A0=A0=A0"memory barrier without comment\n" . $herecurr);