linux-kernel - Re: [PATCH 00/10] make "order" unsigned int

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]

Message-ID: <20190726071219.GC6142@dhcp22.suse.cz>
Date:   Fri, 26 Jul 2019 09:12:19 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Pengfei Li <lpf.vector@...il.com>
Cc:     Qian Cai <cai@....pw>, Andrew Morton <akpm@...ux-foundation.org>,
        mgorman@...hsingularity.net, vbabka@...e.cz,
        aryabinin@...tuozzo.com, osalvador@...e.de, rostedt@...dmis.org,
        mingo@...hat.com, pavel.tatashin@...rosoft.com, rppt@...ux.ibm.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 00/10] make "order" unsigned int

On Fri 26-07-19 07:48:36, Pengfei Li wrote:
[...]
> For the benefit, "order" may be negative, which is confusing and weird.

order = -1 has a special meaning.

> There is no good reason not to do this since it can be avoided.

"This is good because we can do it" doesn't really sound like a
convincing argument to me. I would understand if this reduced a
generated code, made an overall code readability much better or
something along those lines. Also we only use MAX_ORDER range of values
so I could argue that a smaller data type (e.g. short) should be
sufficient for this data type.

Please note that _any_ change, alebit seemingly small, can introduce a
subtle bug. Also each patch requires a man power to review so you have
to understand that "just because we can" is not a strong motivation for
people to spend their time on such a patch.
-- 
Michal Hocko
SUSE Labs