All of lore.kernel.org
 help / color / mirror / Atom feed
From: Minchan Kim <minchan.kim@gmail.com>
To: Ying Han <yinghan@google.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Rik van Riel <riel@redhat.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: [PATCH] vmscan: fix missing place to check nr_swap_pages.
Date: Fri, 27 Aug 2010 10:03:05 +0900	[thread overview]
Message-ID: <AANLkTimaLBJa9hmufqQy3jk7GD-mJDbg=Dqkaja0nOMk@mail.gmail.com> (raw)
In-Reply-To: <1282867897-31201-1-git-send-email-yinghan@google.com>

Hello.

On Fri, Aug 27, 2010 at 9:11 AM, Ying Han <yinghan@google.com> wrote:
> Fix a missed place where checks nr_swap_pages to do shrink_active_list. Make the
> change that moves the check to common function inactive_anon_is_low.
>

Hmm.. AFAIR, we discussed it at that time but we concluded it's not good.
That's because nr_swap_pages < 0 means both "NO SWAP" and "NOT enough
swap space now". If we have a swap device or file but not enough space
now, we need to aging anon pages to make inactive list enough size.
Otherwise, working set pages would be swapped out more fast before
promotion.

That aging is done by kswapd so I think it's not big harmful in the system.
But if you want to remove aging completely in non-swap system, we need
to identify non swap system and not enough swap space. I thought we
need it for embedded system.

Thanks.


-- 
Kind regards,
Minchan Kim

WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan.kim@gmail.com>
To: Ying Han <yinghan@google.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Rik van Riel <riel@redhat.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: [PATCH] vmscan: fix missing place to check nr_swap_pages.
Date: Fri, 27 Aug 2010 10:03:05 +0900	[thread overview]
Message-ID: <AANLkTimaLBJa9hmufqQy3jk7GD-mJDbg=Dqkaja0nOMk@mail.gmail.com> (raw)
In-Reply-To: <1282867897-31201-1-git-send-email-yinghan@google.com>

Hello.

On Fri, Aug 27, 2010 at 9:11 AM, Ying Han <yinghan@google.com> wrote:
> Fix a missed place where checks nr_swap_pages to do shrink_active_list. Make the
> change that moves the check to common function inactive_anon_is_low.
>

Hmm.. AFAIR, we discussed it at that time but we concluded it's not good.
That's because nr_swap_pages < 0 means both "NO SWAP" and "NOT enough
swap space now". If we have a swap device or file but not enough space
now, we need to aging anon pages to make inactive list enough size.
Otherwise, working set pages would be swapped out more fast before
promotion.

That aging is done by kswapd so I think it's not big harmful in the system.
But if you want to remove aging completely in non-swap system, we need
to identify non swap system and not enough swap space. I thought we
need it for embedded system.

Thanks.


-- 
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2010-08-27  1:03 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-27  0:11 [PATCH] vmscan: fix missing place to check nr_swap_pages Ying Han
2010-08-27  0:11 ` Ying Han
2010-08-27  1:03 ` Minchan Kim [this message]
2010-08-27  1:03   ` Minchan Kim
2010-08-27  3:31   ` Ying Han
2010-08-27  3:31     ` Ying Han
2010-08-27  5:00     ` Minchan Kim
2010-08-27  5:00       ` Minchan Kim
2010-08-27 16:35       ` Ying Han
2010-08-27 16:35         ` Ying Han
2010-08-28  1:30         ` Venkatesh Pallipadi
2010-08-28  1:30           ` Venkatesh Pallipadi
2010-08-29 15:42           ` Minchan Kim
2010-08-29 15:42             ` Minchan Kim
2010-08-29 15:40         ` Minchan Kim
2010-08-29 15:40           ` Minchan Kim

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='AANLkTimaLBJa9hmufqQy3jk7GD-mJDbg=Dqkaja0nOMk@mail.gmail.com' \
    --to=minchan.kim@gmail.com \
    --cc=kosaki.motohiro@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=riel@redhat.com \
    --cc=yinghan@google.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.