From: Minchan Kim <minchan.kim@gmail.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Wu Fengguang <fengguang.wu@intel.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH 2/2] vmscan: activate executable pages after first usage
Date: Tue, 9 Aug 2011 09:26:47 +0900 [thread overview]
Message-ID: <CAEwNFnDKsCFWFshHxUkfc3dBTF=0-0eH2ZunyRYt2tcxW72KuA@mail.gmail.com> (raw)
In-Reply-To: <20110809090455.92901845.kamezawa.hiroyu@jp.fujitsu.com>
Hi, Kame.
On Tue, Aug 9, 2011 at 9:04 AM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@jp.fujitsu.com> wrote:
> On Tue, 9 Aug 2011 09:02:28 +0900
> Minchan Kim <minchan.kim@gmail.com> wrote:
>
>> On Mon, Aug 8, 2011 at 8:07 PM, Konstantin Khlebnikov
>> <khlebnikov@openvz.org> 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 =)
>> >
>> > Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
>> > ---
>>
>> It might be a very controversial topic.
>> AFAIR, at least, we did when vmscan: make mapped executable pages the
>> first class citizen was merged. :)
>>
>> You try to change behavior.
>>
>> Old : protect *working set* executable page
>> New: protect executable page *unconditionally*.
>>
>
> Hmm ? I thought
> Old: protect pages if referenced twice
> New: protect executable page if referenced once.
>
> IIUC, ANON is proteced if it's referenced once.
>
> So, this patch changes EXECUTABLE file to the same class as ANON pages.
"Working set" means two reference in implementation of the moment. But
it can change in future as many as we want.
"Unconditionally" means that all of mapped page starts from referenced
pte so it would activate all of executable pages.
>
> Anyway, I agree test/measurement is required.
Absolutely.
--
Kind regards,
Minchan Kim
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-08-09 0:26 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-08 11:06 [PATCH 1/2] vmscan: promote shared file mapped pages Konstantin Khlebnikov
2011-08-08 11:07 ` [PATCH 2/2] vmscan: activate executable pages after first usage Konstantin Khlebnikov
2011-08-08 23:58 ` KAMEZAWA Hiroyuki
2011-08-09 0:02 ` Minchan Kim
2011-08-09 0:04 ` KAMEZAWA Hiroyuki
2011-08-09 0:26 ` Minchan Kim [this message]
2011-08-09 1:23 ` Shaohua Li
2011-08-08 11:37 ` [PATCH 1/2] vmscan: promote shared file mapped pages Pekka Enberg
2011-08-08 12:18 ` Konstantin Khlebnikov
2011-08-08 12:40 ` Pekka Enberg
2011-08-08 12:51 ` Konstantin Khlebnikov
2011-08-18 9:09 ` Johannes Weiner
2011-11-02 16:30 ` Johannes Weiner
2011-11-02 16:31 ` [rfc 1/3] mm: vmscan: never swap under low memory pressure Johannes Weiner
2011-11-02 17:54 ` KOSAKI Motohiro
2011-11-03 15:51 ` Johannes Weiner
2011-11-08 0:16 ` KOSAKI Motohiro
2011-11-07 2:29 ` KAMEZAWA Hiroyuki
2011-11-10 15:29 ` Johannes Weiner
2011-11-02 16:32 ` [rfc 2/3] mm: vmscan: treat inactive cycling as neutral Johannes Weiner
2011-11-02 18:04 ` KOSAKI Motohiro
2011-11-03 12:49 ` Johannes Weiner
2011-11-07 2:34 ` KAMEZAWA Hiroyuki
2011-11-10 16:06 ` Johannes Weiner
2011-11-11 0:05 ` KAMEZAWA Hiroyuki
2011-11-02 16:32 ` [rfc 3/3] mm: vmscan: revert file list boost on lru addition Johannes Weiner
2011-11-07 2:45 ` KAMEZAWA Hiroyuki
2011-11-10 16:12 ` Johannes Weiner
2011-11-02 16:35 ` [PATCH 1/2] vmscan: promote shared file mapped pages Johannes Weiner
2011-08-08 23:36 ` Minchan Kim
2011-08-08 23:51 ` KAMEZAWA Hiroyuki
2011-10-31 20:12 ` Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAEwNFnDKsCFWFshHxUkfc3dBTF=0-0eH2ZunyRYt2tcxW72KuA@mail.gmail.com' \
--to=minchan.kim@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=fengguang.wu@intel.com \
--cc=hannes@cmpxchg.org \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=khlebnikov@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox