linux-kernel - Re: [PATCH 2/2] vmscan: activate executable pages after first usage

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: <1312853009.27321.3.camel@sli10-conroe>
Date:	Tue, 09 Aug 2011 09:23:29 +0800
From:	Shaohua Li <shaohua.li@...el.com>
To:	Konstantin Khlebnikov <khlebnikov@...nvz.org>
Cc:	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Wu, Fengguang" <fengguang.wu@...el.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Johannes Weiner <hannes@...xchg.org>
Subject: Re: [PATCH 2/2] vmscan: activate executable pages after first usage

On Mon, 2011-08-08 at 19:07 +0800, Konstantin Khlebnikov wrote:
> Logic added in commit v2.6.30-5507-g8cab475
> (vmscan: make mapped executable pages the first class citizen)
> was noticeably weakened in commit v2.6.33-5448-g6457474
> (vmscan: detect mapped file pages used only once)
> 
> Currently these pages can become "first class citizens" only after second usage.
> 
> After this patch page_check_references() will activate they after first usage,
> and executable code gets yet better chance to stay in memory.
> 
> TODO:
> run some cool tests like in v2.6.30-5507-g8cab475 =)
I used to post a similar patch here:
http://marc.info/?l=linux-mm&m=128572906801887&w=2
but running Fengguang's test doesn't show improvement. And actually the
VM_EXEC protect in shrink_active_list() doesn't show improvement too in
my run, I'm wondering if we should remove it. I guess the (vmscan:
detect mapped file pages used only once) patch makes VM_EXEC protect
lose its effect. It's great if you can show solid data.

Thanks,
Shaohua

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/