Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 13 Apr 2022 15:55:47 +0800
From:   Muchun Song <songmuchun@bytedance.com>
To:     Peng Liu <liupeng256@huawei.com>
Cc:     mike.kravetz@oracle.com, david@redhat.com,
        akpm@linux-foundation.org, yaozhenguo1@gmail.com,
        baolin.wang@linux.alibaba.com, liuyuntao10@huawei.com,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/4] hugetlb: Fix return value of __setup handlers
Message-ID: <YlaCA6kqjN5nYNSH@FVFYT0MHHV2J.usts.net>
References: <20220413032915.251254-1-liupeng256@huawei.com>
 <20220413032915.251254-4-liupeng256@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220413032915.251254-4-liupeng256@huawei.com>
Precedence: bulk

On Wed, Apr 13, 2022 at 03:29:14AM +0000, Peng Liu wrote:
> When __setup() return '0', using invalid option values causes the
> entire kernel boot option string to be reported as Unknown. Hugetlb
> calls __setup() and will return '0' when set invalid parameter
> string.
> 
> The following phenomenon is observed:
>  cmdline:
>   hugepagesz=1Y hugepages=1
>  dmesg:
>   HugeTLB: unsupported hugepagesz=1Y
>   HugeTLB: hugepages=1 does not follow a valid hugepagesz, ignoring
>   Unknown kernel command line parameters "hugepagesz=1Y hugepages=1"
> 
> Since hugetlb will print warning/error information before return for
> invalid parameter string, just use return '1' to avoid print again.
>

Can't return -EINVAL? It is weird to return 1 on failure.

Thanks.