From: Zheng Liu <gnehzuil.liu@gmail.com>
To: "Lukáš Czerner" <lczerner@redhat.com>
Cc: Jan Kara <jack@suse.cz>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH v3 17/18] ext4: make punch hole code path work with bigalloc
Date: Wed, 24 Apr 2013 19:29:04 +0800 [thread overview]
Message-ID: <20130424112904.GA3128@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1304241303560.24669@localhost>
On Wed, Apr 24, 2013 at 01:08:17PM +0200, Lukáš Czerner wrote:
> On Tue, 23 Apr 2013, Zheng Liu wrote:
[snip]
> > > > Also update respective tracepoints to use signed long long type for
> > > > partial_cluster.
> > > The patch looks OK. You can add:
> > > Reviewed-by: Jan Kara <jack@suse.cz>
> > >
> > > Just a minor nit - sometimes you use 'signed long long', sometimes 'long
> > > long int', sometimes just 'long long'. In kernel we tend to always use just
> > > 'long long' so it would be good to clean that up.
> >
> > Another question is that in patch 01/18 invalidatepage signature is
> > changed from
> > int (*invalidatepage) (struct page *, unsigned long);
> > to
> > void (*invalidatepage) (struct page *, unsigned int, unsigned int);
> >
> > The argument type is changed from 'unsigned long' to 'unsigned int'. My
> > question is why we need to change it.
> >
> > Thanks,
> > - Zheng
> >
>
> Hi Zheng,
>
> this was changed on Hugh Dickins request because it makes it clearer
> that those args are indeed intended to be offsets within a page
> (0..PAGE_CACHE_SIZE).
>
> Even though PAGE_CACHE_SIZE can be defined as unsigned long, this is
> only for convenience. Here is quote from Hugh:
>
> "
> They would be defined as unsigned long so that they can be used in
> masks like ~(PAGE_SIZE - 1), and behave as expected on addresses,
> without needing casts to be added all over.
>
> We do not (currently!) expect PAGE_SIZE or PAGE_CACHE_SIZE to grow
> beyond an unsigned int - but indeed they can be larger than what's
> held in an unsigned short (look no further than ia64 or ppc64).
>
> For more reassurance, see include/linux/highmem.h, which declares
> zero_user_segments() and others: unsigned int (well, unsigned with
> the int implicit) for offsets within a page.
>
> Hugh
> "
>
> I should probably mention that in the description.
Ah, thanks for your explanation. I must miss something. :-(
Regards,
- Zheng
--
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:[~2013-04-24 11:29 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-09 9:14 [PATCH v3 00/18] change invalidatepage prototype to accept length Lukas Czerner
2013-04-09 9:14 ` [PATCH v3 01/18] mm: " Lukas Czerner
2013-04-09 9:14 ` [PATCH v3 02/18] jbd2: change jbd2_journal_invalidatepage " Lukas Czerner
2013-04-09 13:22 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 03/18] ext4: use ->invalidatepage() length argument Lukas Czerner
2013-04-09 13:24 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 04/18] jbd: change journal_invalidatepage() to accept length Lukas Czerner
2013-04-09 13:20 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 05/18] xfs: use ->invalidatepage() length argument Lukas Czerner
2013-04-23 14:14 ` Theodore Ts'o
2013-04-23 21:06 ` Ben Myers
2013-04-09 9:14 ` [PATCH v3 06/18] ocfs2: " Lukas Czerner
2013-04-09 13:26 ` Jan Kara
2013-04-23 14:16 ` Theodore Ts'o
2013-05-02 22:00 ` Joel Becker
2013-04-09 9:14 ` [PATCH v3 07/18] ceph: " Lukas Czerner
2013-04-23 14:14 ` Theodore Ts'o
2013-04-23 16:04 ` Sage Weil
2013-04-09 9:14 ` [PATCH v3 08/18] gfs2: " Lukas Czerner
2013-04-09 9:29 ` [Cluster-devel] " Steven Whitehouse
2013-04-09 13:09 ` Bob Peterson
2013-04-09 13:27 ` Lukáš Czerner
2013-04-23 14:16 ` Theodore Ts'o
2013-04-23 14:17 ` Theodore Ts'o
2013-04-09 9:14 ` [PATCH v3 09/18] reiserfs: " Lukas Czerner
2013-04-09 13:27 ` Jan Kara
2013-04-10 9:51 ` Lukáš Czerner
2013-04-09 9:14 ` [PATCH v3 10/18] mm: teach truncate_inode_pages_range() to handle non page aligned ranges Lukas Czerner
2013-04-11 21:18 ` Jan Kara
2013-04-11 22:40 ` Hugh Dickins
2013-04-09 9:14 ` [PATCH v3 11/18] Revert "ext4: remove no longer used functions in inode.c" Lukas Czerner
2013-04-18 22:08 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 12/18] Revert "ext4: fix fsx truncate failure" Lukas Czerner
2013-04-18 22:21 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 13/18] ext4: use ext4_zero_partial_blocks in punch_hole Lukas Czerner
2013-04-19 5:03 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 14/18] ext4: remove unused discard_partial_page_buffers Lukas Czerner
2013-04-19 5:04 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 15/18] ext4: remove unused code from ext4_remove_blocks() Lukas Czerner
2013-04-19 5:15 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 16/18] ext4: update ext4_ext_remove_space trace point Lukas Czerner
2013-04-19 5:16 ` Jan Kara
2013-04-09 9:14 ` [PATCH v3 17/18] ext4: make punch hole code path work with bigalloc Lukas Czerner
2013-04-20 13:42 ` Jan Kara
2013-04-23 9:19 ` Zheng Liu
2013-04-24 11:08 ` Lukáš Czerner
2013-04-24 11:29 ` Zheng Liu [this message]
2013-04-24 10:57 ` Lukáš Czerner
2013-04-09 9:14 ` [PATCH v3 18/18] ext4: Allow punch hole with bigalloc enabled Lukas Czerner
2013-04-20 13:43 ` Jan Kara
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=20130424112904.GA3128@gmail.com \
--to=gnehzuil.liu@gmail.com \
--cc=jack@suse.cz \
--cc=lczerner@redhat.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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;
as well as URLs for NNTP newsgroup(s).