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Message-ID: <9defa63ffed0e526269672776c94eca36af6afae.camel@perches.com>
Subject: Re: [PATCH v3] checkpatch: ignore warning designated initializers
 using NR_CPUS
From:   Joe Perches <joe@perches.com>
To:     Peng Wang <rocking@linux.alibaba.com>, apw@canonical.com,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-kernel@vger.kernel.org
Date:   Wed, 30 Dec 2020 04:38:56 -0800
In-Reply-To: <5d4998aa8a8ac7efada2c7daffa9e73559f8b186.1609331255.git.rocking@linux.alibaba.com>
References: <5ca6c2d28f6cf091a676f8e7d8f14a933da0b267.camel@perches.com>
         <5d4998aa8a8ac7efada2c7daffa9e73559f8b186.1609331255.git.rocking@linux.alibaba.com>
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On Wed, 2020-12-30 at 20:29 +0800, Peng Wang wrote:
> 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>
> ---
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -7028,12 +7028,14 @@ 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);

Thanks.

Acked-by: Joe Perches <joe@perches.com>