linux-kernel - Re: [PATCH 2/5] mm/debug_pagealloc: don't allocate page

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:	Wed, 10 Aug 2016 18:44:42 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:	js1304@...il.com
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Vlastimil Babka <vbabka@...e.cz>,
	Minchan Kim <minchan@...nel.org>,
	Michal Hocko <mhocko@...nel.org>,
	Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: Re: [PATCH 2/5] mm/debug_pagealloc: don't allocate page_ext if we
 don't use guard page

On (08/10/16 15:16), js1304@...il.com wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@....com>
> 
> What debug_pagealloc does is just mapping/unmapping page table.
> Basically, it doesn't need additional memory space to memorize something.
> But, with guard page feature, it requires additional memory to distinguish
> if the page is for guard or not. Guard page is only used when
> debug_guardpage_minorder is non-zero so this patch removes additional
> memory allocation (page_ext) if debug_guardpage_minorder is zero.
> 
> It saves memory if we just use debug_pagealloc and not guard page.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>

	-ss