LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Chuck Ebbert <cebbert@redhat.com>
To: Rik van Riel <riel@redhat.com>
Cc: Nikita Danilov <nikita@clusterfs.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-mm <linux-mm@kvack.org>
Subject: Re: [RFC][PATCH] split file and anonymous page queues #3
Date: Wed, 21 Mar 2007 12:12:58 -0400	[thread overview]
Message-ID: <4601598A.7060904@redhat.com> (raw)
In-Reply-To: <46011E8F.2000109@redhat.com>

Rik van Riel wrote:
> Nikita Danilov wrote:
> 
>> Probably I am missing something, but I don't see how that can help. For
>> example, suppose (for simplicity) that we have swappiness of 100%, and
>> that fraction of referenced anon pages gets slightly less than of file
>> pages. get_scan_ratio() increases anon_percent, and shrink_zone() starts
>> scanning anon queue more aggressively. As a result, pages spend less
>> time there, and have less chance of ever being accessed, reducing
>> fraction of referenced anon pages further, and triggering further
>> increase in the amount of scanning, etc. Doesn't this introduce positive
>> feed-back loop?
> 
> It's a possibility, but I don't think it will be much of an
> issue in practice.
> 
> If it is, we can always use refaults as a correcting
> mechanism - which would have the added benefit of being
> able to do streaming IO without putting any pressure on
> the active list, essentially clock-pro replacement with
> just some tweaks to shrink_list()...
> 

I think you're going to have to use refault rates. AIX 3.5 had
to add that. Something like:

if refault_rate(anonymous/mmap) > refault_rate(pagecache)
   drop a pagecache page
else
   drop either

You do have anonymous memory and mmapped executables in the same
queue, right?



  parent reply	other threads:[~2007-03-21 16:13 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-20 22:08 Rik van Riel
2007-03-21  1:07 ` Matt Mackall
2007-03-21 19:11   ` Rik van Riel
2007-03-21  8:44 ` Nikita Danilov
2007-03-21 11:24   ` Rik van Riel
2007-03-21 11:48     ` Nikita Danilov
2007-03-21 12:01       ` Rik van Riel
2007-03-21 12:03         ` Rik van Riel
2007-03-21 15:29           ` Nikita Danilov
2007-03-21 16:08             ` Rik van Riel
2007-03-21 22:18               ` Nikita Danilov
2007-03-21 16:12         ` Chuck Ebbert [this message]
2007-03-21 16:56           ` Rik van Riel
  -- strict thread matches above, loose matches on Subject: below --
2007-03-20 22:06 Rik van Riel

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=4601598A.7060904@redhat.com \
    --to=cebbert@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=nikita@clusterfs.com \
    --cc=riel@redhat.com \
    --subject='Re: [RFC][PATCH] split file and anonymous page queues #3' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).