From: Andrew Morton <akpm@osdl.org>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: andrea@novell.com, riel@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: lowmem_reserve (replaces protection)
Date: Tue, 26 Oct 2004 20:43:08 -0700 [thread overview]
Message-ID: <20041026204308.73ee438b.akpm@osdl.org> (raw)
In-Reply-To: <417F1746.2080607@yahoo.com.au>
Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> It actually can overscan lower zones a little bit, because
> whenever any higher zone in the pgdat is low on memory, then
> it and all zones below it get scanned too.
Because we know that all of the eligible zones are below pages_low. kswapd
will then work to bring all the relevant zones back to pages_high.
When working on this code it is very very easy to break the zone levelling:
you *have* to run a workload mix and monitor the numbers in /proc/vmstat to
ensure that all zones are undergoing page scanning at frequencies which are
proportional to their sizes. It's easy to screw up the zone levelling so
all allocations end up coming from ZONE_NORMAL and pagecache pages in, say,
ZONE_DMA end up just sitting there.
next prev parent reply other threads:[~2004-10-27 3:46 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-25 17:01 lowmem_reserve (replaces protection) Andrea Arcangeli
2004-10-26 1:48 ` Rik van Riel
2004-10-26 1:58 ` Andrea Arcangeli
2004-10-26 3:48 ` Nick Piggin
2004-10-26 4:04 ` Andrea Arcangeli
2004-10-26 4:17 ` Nick Piggin
2004-10-27 0:25 ` Andrea Arcangeli
2004-10-27 0:42 ` Andrew Morton
2004-10-27 0:48 ` Andrea Arcangeli
2004-10-27 2:06 ` Nick Piggin
2004-10-28 0:26 ` Andrea Arcangeli
2004-10-27 0:31 ` Rik van Riel
2004-10-27 0:54 ` Andrea Arcangeli
2004-10-27 0:56 ` Andrea Arcangeli
2004-10-27 1:35 ` Andrea Arcangeli
2004-10-27 2:08 ` Andrew Morton
2004-10-27 2:31 ` Andrea Arcangeli
2004-10-27 2:56 ` Nick Piggin
2004-10-27 1:00 ` Rik van Riel
2004-10-27 1:10 ` Andrea Arcangeli
2004-10-27 2:05 ` Nick Piggin
2004-10-27 2:29 ` Andrea Arcangeli
2004-10-27 3:01 ` Nick Piggin
2004-10-27 3:23 ` Andrea Arcangeli
2004-10-27 3:34 ` Nick Piggin
2004-10-27 3:43 ` Andrew Morton [this message]
2004-10-27 4:44 ` Andrea Arcangeli
2004-10-27 4:51 ` Rik van Riel
2004-10-27 5:05 ` Andrea Arcangeli
2004-10-27 5:50 ` Nick Piggin
2004-10-27 5:33 ` Andrew Morton
2004-10-27 6:11 ` Andrea Arcangeli
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=20041026204308.73ee438b.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=andrea@novell.com \
--cc=linux-kernel@vger.kernel.org \
--cc=nickpiggin@yahoo.com.au \
--cc=riel@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox