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From:   Peng Wang <rocking@linux.alibaba.com>
To:     apw@canonical.com, joe@perches.com
Cc:     linux-kernel@vger.kernel.org
Subject: [PATCH v2] checkpatch: ignore warning designated initializers using NR_CPUS
Date:   Wed, 30 Dec 2020 15:14:08 +0800
Message-Id: <334ce7b5136e25bd4b10309abc36c18d75bb0d33.1609311092.git.rocking@linux.alibaba.com>
In-Reply-To: <5ca6c2d28f6cf091a676f8e7d8f14a933da0b267.camel@perches.com>
References: <5ca6c2d28f6cf091a676f8e7d8f14a933da0b267.camel@perches.com>
Precedence: bulk

Some max_length wants to hold as large room as possible to
ensure enough size to tackle with the biggest NR_CPUS.
An example below:

kernel/cgroup/cpuset.c:
static struct cftype legacy_files[] = {
        {
                .name = "cpus",
                .seq_show = cpuset_common_seq_show,
                .write = cpuset_write_resmask,
                .max_write_len = (100U + 6 * NR_CPUS),
                .private = FILE_CPULIST,
        },
	...
}

Signed-off-by: Peng Wang <rocking@linux.alibaba.com>
---
 scripts/checkpatch.pl | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 0008530..fdbbab3 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7022,12 +7022,15 @@ sub process {
 
 # use of NR_CPUS is usually wrong
 # ignore definitions of NR_CPUS and usage to define arrays as likely right
+# ignore designated initializers using NR_CPUS
+
 		if ($line =~ /\bNR_CPUS\b/ &&
 		    $line !~ /^.\s*\s*#\s*if\b.*\bNR_CPUS\b/ &&
 		    $line !~ /^.\s*\s*#\s*define\b.*\bNR_CPUS\b/ &&
 		    $line !~ /^.\s*$Declare\s.*\[[^\]]*NR_CPUS[^\]]*\]/ &&
 		    $line !~ /\[[^\]]*\.\.\.[^\]]*NR_CPUS[^\]]*\]/ &&
-		    $line !~ /\[[^\]]*NR_CPUS[^\]]*\.\.\.[^\]]*\]/)
+		    $line !~ /\[[^\]]*NR_CPUS[^\]]*\.\.\.[^\]]*\]/ &&
+		    $line !~ /^.\s*\.\w+\s*=\s*.*\bNR_CPUS\b/)
 		{
 			WARN("NR_CPUS",
 			     "usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" . $herecurr);
-- 
2.9.5