From: Andrew Morton <akpm@osdl.org>
To: Blaisorblade <blaisorblade_spam@yahoo.it>
Cc: linux-kernel@vger.kernel.org, jdike@addtoit.com,
bstroesser@fujitsu-siemens.com,
user-mode-linux-devel@lists.sourceforge.net, kraxel@bytesex.org
Subject: [uml-devel] Re: VFS interactions with UML and other big UML changes (was: Re: [patch 1/2] Uml - first part rework of run_helper() and users.)
Date: Tue, 30 Nov 2004 16:33:52 -0800 [thread overview]
Message-ID: <20041130163352.62840d12.akpm@osdl.org> (raw)
In-Reply-To: <200412010120.39579.blaisorblade_spam@yahoo.it>
Blaisorblade <blaisorblade_spam@yahoo.it> wrote:
>
> static struct address_space_operations hostfs_aops = {
> .writepage = hostfs_writepage,
> .readpage = hostfs_readpage,
> /* .set_page_dirty = __set_page_dirty_nobuffers, */
> .prepare_write = hostfs_prepare_write,
> .commit_write = hostfs_commit_write
> };
>
> Actually, hostfs is a nodev filesystem, but I simply don't know if that
> implies that it uses no buffers. So, should
>
> .set_page_dirty = __set_page_dirty_nobuffers
>
> be uncommented? Or should it be deleted (leaving it there is not a good
> option).
See the operation of set_page_dirty().
If you have NULL ->set_page_dirty a_op then set_page_dirty() will fall
through to __set_page_dirty_buffers().
If your fs never sets PG_private then __set_page_dirty_buffers() will just
do what __set_page_dirty_nobuffers() does.
Without having looked at it, I'm sure that hostfs does not use
buffer_heads. So setting your ->set_page_dirty a_op to point at
__set_page_dirty_nobuffers() is a reasonable thing to do - it'll provide a
slight speedup.
-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://productguide.itmanagersjournal.com/
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@osdl.org>
To: Blaisorblade <blaisorblade_spam@yahoo.it>
Cc: linux-kernel@vger.kernel.org, jdike@addtoit.com,
bstroesser@fujitsu-siemens.com,
user-mode-linux-devel@lists.sourceforge.net, kraxel@bytesex.org
Subject: Re: VFS interactions with UML and other big UML changes (was: Re: [patch 1/2] Uml - first part rework of run_helper() and users.)
Date: Tue, 30 Nov 2004 16:33:52 -0800 [thread overview]
Message-ID: <20041130163352.62840d12.akpm@osdl.org> (raw)
In-Reply-To: <200412010120.39579.blaisorblade_spam@yahoo.it>
Blaisorblade <blaisorblade_spam@yahoo.it> wrote:
>
> static struct address_space_operations hostfs_aops = {
> .writepage = hostfs_writepage,
> .readpage = hostfs_readpage,
> /* .set_page_dirty = __set_page_dirty_nobuffers, */
> .prepare_write = hostfs_prepare_write,
> .commit_write = hostfs_commit_write
> };
>
> Actually, hostfs is a nodev filesystem, but I simply don't know if that
> implies that it uses no buffers. So, should
>
> .set_page_dirty = __set_page_dirty_nobuffers
>
> be uncommented? Or should it be deleted (leaving it there is not a good
> option).
See the operation of set_page_dirty().
If you have NULL ->set_page_dirty a_op then set_page_dirty() will fall
through to __set_page_dirty_buffers().
If your fs never sets PG_private then __set_page_dirty_buffers() will just
do what __set_page_dirty_nobuffers() does.
Without having looked at it, I'm sure that hostfs does not use
buffer_heads. So setting your ->set_page_dirty a_op to point at
__set_page_dirty_nobuffers() is a reasonable thing to do - it'll provide a
slight speedup.
next prev parent reply other threads:[~2004-12-01 0:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-30 20:08 [uml-devel] [patch 1/2] Uml - first part rework of run_helper() and users blaisorblade_spam
2004-11-30 23:20 ` [uml-devel] " Andrew Morton
2004-12-01 0:20 ` [uml-devel] VFS interactions with UML and other big UML changes (was: Re: [patch 1/2] Uml - first part rework of run_helper() and users.) Blaisorblade
2004-12-01 0:20 ` Blaisorblade
2004-12-01 0:33 ` Andrew Morton [this message]
2004-12-01 0:33 ` Andrew Morton
2004-12-01 0:51 ` [uml-devel] " Blaisorblade
2004-12-01 0:51 ` Blaisorblade
2004-12-01 9:02 ` Gerd Knorr
2004-12-01 9:02 ` Gerd Knorr
2004-12-02 1:41 ` [uml-devel] Re: [patch 1/2] Uml - first part rework of run_helper() and users Jeff Dike
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=20041130163352.62840d12.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=blaisorblade_spam@yahoo.it \
--cc=bstroesser@fujitsu-siemens.com \
--cc=jdike@addtoit.com \
--cc=kraxel@bytesex.org \
--cc=linux-kernel@vger.kernel.org \
--cc=user-mode-linux-devel@lists.sourceforge.net \
/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.