linux-kernel - Re: [PATCH 2/3] sgi-gru: Remove CONFIG_HUGETLB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 22 Jul 2019 16:53:53 -0600
From:   William Kucharski <william.kucharski@...cle.com>
To:     Bharath Vedartham <linux.bhar@...il.com>
Cc:     arnd@...db.de, sivanich@....com, gregkh@...uxfoundation.org,
        ira.weiny@...el.com, jhubbard@...dia.com, jglisse@...hat.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 2/3] sgi-gru: Remove CONFIG_HUGETLB_PAGE ifdef



> On Jul 22, 2019, at 11:50 AM, Bharath Vedartham <linux.bhar@...il.com> wrote:
> 
>> 
>> 
>> 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.
>> 
> That sounds reasonable. I am not really sure as to how much of 
> 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@...cle.com>