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Subject: Re: [PATCH v2] mm/hugepages: fix "orig_pud" set but not used
To:     Souptick Joarder <jrdr.linux@gmail.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>,
        Linux-MM <linux-mm@kvack.org>, linux-kernel@vger.kernel.org
References: <20190301221956.97493-1-cai@lca.pw>
 <CAFqt6zZr8ZCM6_7QDzDEf=5gH=+EkaumXk86X35dGTdn_SLvvA@mail.gmail.com>
From:   Qian Cai <cai@lca.pw>
Message-ID: <935fc484-70e3-ed7a-ed82-329529e0e280@lca.pw>
Date:   Mon, 4 Mar 2019 09:09:12 -0500
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On 3/4/19 7:02 AM, Souptick Joarder wrote:
> On Sat, Mar 2, 2019 at 3:50 AM Qian Cai <cai@lca.pw> wrote:
>>
>> The commit a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent
>> hugepages") introduced pudp_huge_get_and_clear_full() but no one uses
>> its return code. In order to not diverge from
>> pmdp_huge_get_and_clear_full(), just change zap_huge_pud() to not assign
>> the return value from pudp_huge_get_and_clear_full().
>>
>> mm/huge_memory.c: In function 'zap_huge_pud':
>> mm/huge_memory.c:1982:8: warning: variable 'orig_pud' set but not used
>> [-Wunused-but-set-variable]
>>   pud_t orig_pud;
>>         ^~~~~~~~
>>
> 
> 4th argument passed to pudp_huge_get_and_clear_full() is not used.
> Is it fine to remove *int full * in  pudp_huge_get_and_clear_full() if
> there is no plan to use it in future ?
> 
> This is applicable to below functions as well -
> pmdp_huge_get_and_clear_full()
> ptep_get_and_clear_full()
> pte_clear_not_present_full()

I suppose arches may override those that could make use of "int full".