linux-kernel - Re: [PATCH v6 1/4] mm: hugetlb_vmemmap: introduce STRUCT_PAGE_SIZE_IS_POWER_OF

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: <20220330195759.6da783a678229008ac2a6851@linux-foundation.org>
Date:   Wed, 30 Mar 2022 19:57:59 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Muchun Song <songmuchun@...edance.com>
Cc:     Jonathan Corbet <corbet@....net>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Iurii Zaikin <yzaikin@...gle.com>,
        Oscar Salvador <osalvador@...e.de>,
        David Hildenbrand <david@...hat.com>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Linux Doc Mailing List <linux-doc@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux Memory Management List <linux-mm@...ck.org>,
        Xiongchun duan <duanxiongchun@...edance.com>,
        Muchun Song <smuchun@...il.com>
Subject: Re: [PATCH v6 1/4] mm: hugetlb_vmemmap: introduce
 STRUCT_PAGE_SIZE_IS_POWER_OF_2

On Thu, 31 Mar 2022 10:52:58 +0800 Muchun Song <songmuchun@...edance.com> wrote:

> > > +int main(void)
> > > +{
> > > +     if (is_power_of_2(sizeof(struct page)))
> > > +             DEFINE(STRUCT_PAGE_SIZE_IS_POWER_OF_2, is_power_of_2(sizeof(struct page)));
> >
> > Why not
> >
> >         DEFINE(STRUCT_PAGE_SIZE_IS_POWER_OF_2, 1);
> >
> 
> Yep, this is more simple.  But the 2nd parameter of DEFINE() will
> go into the comments.  I want to make it more clear when someone
> reads the code of this macro.  The two different sentences will
> generate the following two different comments.  Which one do
> you think is better?
> 
> #define STRUCT_PAGE_SIZE_IS_POWER_OF_2 1 /*
> is_power_of_2(sizeof(struct page)) */
> #define STRUCT_PAGE_SIZE_IS_POWER_OF_2 1 /* 1 */

The former ;)