From: William Lee Irwin III <wli@holomorphy.com>
To: Matt Mackall <mpm@selenic.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Miklos Szeredi <miklos@szeredi.hu>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems
Date: Mon, 26 Mar 2007 17:02:10 -0700 [thread overview]
Message-ID: <20070327000210.GZ2986@holomorphy.com> (raw)
In-Reply-To: <20070325155127.GR10459@waste.org>
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote:
>>> Dirty page accounting/limiting doesn't work for nonlinear mappings, so
>>> for non-ram backed filesystems emulate with linear mappings. This
>>> retains ABI compatibility with previous kernels at minimal code cost.
>>> All known users of nonlinear mappings actually use tmpfs, so this
>>> shouldn't have any negative effect.
On Sun, Mar 25, 2007 at 02:12:32PM +0200, Peter Zijlstra wrote:
On Sun, Mar 25, 2007 at 10:51:27AM -0500, Matt Mackall wrote:
> They do? I thought the whole point of nonlinear mappings was for
> mapping files bigger than the address space (eg. databases). Is Oracle
> instead using this to map >3G files on a tmpfs??
It's used for > 3GB files on tmpfs and also ramfs, sometimes
substantially larger than 3GB.
It's not used for the database proper. It's used for the buffer pool,
which is the in-core destination and source of direct I/O, the on-disk
source and destination of the I/O being the database.
-- wli
WARNING: multiple messages have this Message-ID (diff)
From: William Lee Irwin III <wli@holomorphy.com>
To: Matt Mackall <mpm@selenic.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Miklos Szeredi <miklos@szeredi.hu>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems
Date: Mon, 26 Mar 2007 17:02:10 -0700 [thread overview]
Message-ID: <20070327000210.GZ2986@holomorphy.com> (raw)
In-Reply-To: <20070325155127.GR10459@waste.org>
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote:
>>> Dirty page accounting/limiting doesn't work for nonlinear mappings, so
>>> for non-ram backed filesystems emulate with linear mappings. This
>>> retains ABI compatibility with previous kernels at minimal code cost.
>>> All known users of nonlinear mappings actually use tmpfs, so this
>>> shouldn't have any negative effect.
On Sun, Mar 25, 2007 at 02:12:32PM +0200, Peter Zijlstra wrote:
On Sun, Mar 25, 2007 at 10:51:27AM -0500, Matt Mackall wrote:
> They do? I thought the whole point of nonlinear mappings was for
> mapping files bigger than the address space (eg. databases). Is Oracle
> instead using this to map >3G files on a tmpfs??
It's used for > 3GB files on tmpfs and also ramfs, sometimes
substantially larger than 3GB.
It's not used for the database proper. It's used for the buffer pool,
which is the in-core destination and source of direct I/O, the on-disk
source and destination of the I/O being the database.
-- wli
--
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>
next prev parent reply other threads:[~2007-03-27 0:02 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-24 22:07 [patch 1/3] split mmap Miklos Szeredi
2007-03-24 22:07 ` Miklos Szeredi, Miklos Szeredi
2007-03-24 22:09 ` [patch 2/3] only allow nonlinear vmas for ram backed filesystems Miklos Szeredi
2007-03-24 22:09 ` Miklos Szeredi, Miklos Szeredi
2007-03-25 12:12 ` Peter Zijlstra
2007-03-25 12:12 ` Peter Zijlstra
2007-03-25 15:51 ` Matt Mackall
2007-03-25 15:51 ` Matt Mackall
2007-03-27 0:02 ` William Lee Irwin III [this message]
2007-03-27 0:02 ` William Lee Irwin III
2007-03-26 0:00 ` Andrew Morton
2007-03-26 0:00 ` Andrew Morton
2007-03-26 6:57 ` Peter Zijlstra
2007-03-26 6:57 ` Peter Zijlstra
2007-03-24 22:11 ` [patch 3/3] update ctime and mtime for mmaped write Miklos Szeredi
2007-03-24 22:11 ` Miklos Szeredi, Miklos Szeredi
2007-03-25 12:12 ` Peter Zijlstra
2007-03-25 12:12 ` Peter Zijlstra
2007-03-25 21:08 ` Miklos Szeredi
2007-03-25 21:08 ` Miklos Szeredi
2007-03-25 12:12 ` [patch 1/3] split mmap Peter Zijlstra
2007-03-25 12:12 ` Peter Zijlstra
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=20070327000210.GZ2986@holomorphy.com \
--to=wli@holomorphy.com \
--cc=a.p.zijlstra@chello.nl \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=miklos@szeredi.hu \
--cc=mpm@selenic.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.