linux-kernel - Re: [PATCH] mm/swap_state.c: use the same way to count page in [add_to|delete_from]_swap

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:   Sat, 14 Mar 2020 17:21:01 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Wei Yang <richard.weiyang@...il.com>
Cc:     akpm@...ux-foundation.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm/swap_state.c: use the same way to count page in
 [add_to|delete_from]_swap_cache

On Sat, Mar 14, 2020 at 09:59:12PM +0000, Wei Yang wrote:
> Function add_to_swap_cache() and delete_from_swap_cache() are counter
> parts, while currently they use different way to count page.
> 
> It doesn't break any thing because we only have two size for PageAnon,
> but this is confusing and not a good practice.
> 
> This patch corrects it by both using compound_nr().

You're converting in the wrong direction.  hpage_nr_pages() is optimised
away when CONFIG_TRANSPARENT_HUGEPAGE is undefined, whereas compound_nr()
is not.

I also have this patch pending:
http://git.infradead.org/users/willy/linux-dax.git/commitdiff/192b635b428ae74f680574cdcc3d5e9d213fcb64