From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andrea Arcangeli <andrea@novell.com>
Cc: Rik van Riel <riel@redhat.com>, Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org
Subject: Re: lowmem_reserve (replaces protection)
Date: Wed, 27 Oct 2004 13:34:30 +1000 [thread overview]
Message-ID: <417F1746.2080607@yahoo.com.au> (raw)
In-Reply-To: <20041027032338.GU14325@dualathlon.random>
Andrea Arcangeli wrote:
> On Wed, Oct 27, 2004 at 01:01:54PM +1000, Nick Piggin wrote:
>
>>Currently it does not overschedule, because one zone is always
>>going to be low by the time kswapd wakes up. This causes all zones
>>below to be scanned as well.
>
>
> that's quite subtle (after all it's needed only for the numa pgdats) and
> I agree on the wakeup side, the one thing that is wrong instead is the
> kswapd-stop side. On that side you really need to know every single zone
> that has to be balanced. So whatever, you can't just use pages_high
> there. I'm creating a zone->max_lowmem_reserve to fix that efficiently
> (that's recalculated every time with the sysctl and at boot).
>
> However my patch to wakeup_kswapd sure wouldn't hurt there.
>
You do though... it is right as is (sort of).
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.
So if HIGHMEM is low on memory, NORMAL and DMA get scanned
as well regardless. If NORMAL is low, then DMA gets scanned
as well.
next prev parent reply other threads:[~2004-10-27 3:38 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 [this message]
2004-10-27 3:43 ` Andrew Morton
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=417F1746.2080607@yahoo.com.au \
--to=nickpiggin@yahoo.com.au \
--cc=akpm@osdl.org \
--cc=andrea@novell.com \
--cc=linux-kernel@vger.kernel.org \
--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