Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain;
        charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3566.0.1\))
Subject: Re: [PATCH 2/3] sgi-gru: Remove CONFIG_HUGETLB_PAGE ifdef
From:   William Kucharski <william.kucharski@oracle.com>
In-Reply-To: <20190722175022.GB12278@bharath12345-Inspiron-5559>
Date:   Mon, 22 Jul 2019 16:53:53 -0600
Cc:     arnd@arndb.de, sivanich@sgi.com, gregkh@linuxfoundation.org,
        ira.weiny@intel.com, jhubbard@nvidia.com, jglisse@redhat.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <58D68134-E068-466C-AAD8-FA69596E8C26@oracle.com>
References: <1563724685-6540-1-git-send-email-linux.bhar@gmail.com>
 <1563724685-6540-3-git-send-email-linux.bhar@gmail.com>
 <1BA84A99-4EB5-4520-BFBD-CD60D5B7AED9@oracle.com>
 <20190722175022.GB12278@bharath12345-Inspiron-5559>
To:     Bharath Vedartham <linux.bhar@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Jul 22, 2019, at 11:50 AM, Bharath Vedartham <linux.bhar@gmail.com> =
wrote:
>=20
>>=20
>>=20
>> In all likelihood, these questions are no-ops, and the optimizer may =
even make my questions completely moot, but I thought I might as well =
ask anyway.
>>=20
> That sounds reasonable. I am not really sure as to how much of=20
> an improvement it would be, the condition will be evaluated eitherways
> AFAIK? Eitherways, the ternary operator does not look good. I ll make =
a
> version 2 of this.

In THEORY the "unlikely" hints to the compiler that that leg of the "if" =
can be made the branch and jump leg, though in reality optimization is =
much more complex than that.

Still, the unlikely() call is also nicely self-documenting as to what =
the expected outcome is.

Reviewed-by: William Kucharski <william.kucharski@oracle.com>