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Date:   Mon, 22 May 2023 13:28:51 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Lorenzo Stoakes <lstoakes@gmail.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Mike Rapoport <rppt@kernel.org>,
        "Liam R . Howlett" <Liam.Howlett@Oracle.com>,
        Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH] mm/mmap: refactor mlock_future_check()
Message-Id: <20230522132851.ccc9fafac91d7eb9ba922e94@linux-foundation.org>
In-Reply-To: <20230522082412.56685-1-lstoakes@gmail.com>
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On Mon, 22 May 2023 09:24:12 +0100 Lorenzo Stoakes <lstoakes@gmail.com> wrote:

> In all but one instance, mlock_future_check() is treated as a boolean
> function despite returning an error code. In one instance, this error code
> is ignored and replaced with -ENOMEM.
> 
> This is confusing, and the inversion of true -> failure, false -> success
> is not warranted. Convert the function to a bool, lightly refactor and
> return true if the check passes, false if not.

Yup.

I don't think the name does a good job of conveying the
function's use.

> -	if (mlock_future_check(mm, vm_flags, len))
> +	if (!mlock_future_check(mm, vm_flags, len))
>  		return -EAGAIN;

	if (!may_mlock_future(...))

or

	if (!mlock_future_ok(...))

?