From: zhangxiao <xiao.zhang@windriver.com>
To: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
dm-devel@redhat.com
Subject: Re: The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible?
Date: Tue, 2 Dec 2014 16:40:37 +0800 [thread overview]
Message-ID: <547D7B05.50406@windriver.com> (raw)
In-Reply-To: <20141202193618.6d3adb22@notabene.brown>
On 2014年12月02日 16:36, NeilBrown wrote:
> On Tue, 2 Dec 2014 16:32:14 +0800 zhangxiao <xiao.zhang@windriver.com> wrote:
>
>> Hi NeilBrown,
>>
>> See drivers/md/dm-bufio.c as below:
>> 50 /*
>> 51 * Buffer hash
>> 52 */
>> 53 #define DM_BUFIO_HASH_BITS 20
>> 54 #define DM_BUFIO_HASH(block) \
>> 55 ((((block) >> DM_BUFIO_HASH_BITS) ^ (block)) & \
>> 56 ((1 << DM_BUFIO_HASH_BITS) - 1))
>> "drivers/md/dm-bufio.c" 1854L, 45375C
>>
>>
>> DM_BUFIO_HASH_BITS was defined as 20 and it maybe not fit for some
>> use case with limited resources. Do we have any plan to make it more
>> flexible? Like module parameter or something else?
>>
>
> Thanks, but this question should be address to:
>
Thank you for your kindly remind. :-)
Regards
Xiao
> DEVICE-MAPPER (LVM)
> M: Alasdair Kergon <agk@redhat.com>
> M: Mike Snitzer <snitzer@redhat.com>
> M: dm-devel@redhat.com
> L: dm-devel@redhat.com
> W: http://sources.redhat.com/dm
> Q: http://patchwork.kernel.org/project/dm-devel/list/
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git
> T: quilt http://people.redhat.com/agk/patches/linux/editing/
> S: Maintained
> F: Documentation/device-mapper/
> F: drivers/md/dm*
> F: drivers/md/persistent-data/
> F: include/linux/device-mapper.h
> F: include/linux/dm-*.h
> F: include/uapi/linux/dm-*.h
>
> NeilBrown
>
WARNING: multiple messages have this Message-ID (diff)
From: zhangxiao <xiao.zhang@windriver.com>
To: NeilBrown <neilb@suse.de>
Cc: <linux-raid@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<dm-devel@redhat.com>
Subject: Re: The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible?
Date: Tue, 2 Dec 2014 16:40:37 +0800 [thread overview]
Message-ID: <547D7B05.50406@windriver.com> (raw)
In-Reply-To: <20141202193618.6d3adb22@notabene.brown>
On 2014年12月02日 16:36, NeilBrown wrote:
> On Tue, 2 Dec 2014 16:32:14 +0800 zhangxiao <xiao.zhang@windriver.com> wrote:
>
>> Hi NeilBrown,
>>
>> See drivers/md/dm-bufio.c as below:
>> 50 /*
>> 51 * Buffer hash
>> 52 */
>> 53 #define DM_BUFIO_HASH_BITS 20
>> 54 #define DM_BUFIO_HASH(block) \
>> 55 ((((block) >> DM_BUFIO_HASH_BITS) ^ (block)) & \
>> 56 ((1 << DM_BUFIO_HASH_BITS) - 1))
>> "drivers/md/dm-bufio.c" 1854L, 45375C
>>
>>
>> DM_BUFIO_HASH_BITS was defined as 20 and it maybe not fit for some
>> use case with limited resources. Do we have any plan to make it more
>> flexible? Like module parameter or something else?
>>
>
> Thanks, but this question should be address to:
>
Thank you for your kindly remind. :-)
Regards
Xiao
> DEVICE-MAPPER (LVM)
> M: Alasdair Kergon <agk@redhat.com>
> M: Mike Snitzer <snitzer@redhat.com>
> M: dm-devel@redhat.com
> L: dm-devel@redhat.com
> W: http://sources.redhat.com/dm
> Q: http://patchwork.kernel.org/project/dm-devel/list/
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git
> T: quilt http://people.redhat.com/agk/patches/linux/editing/
> S: Maintained
> F: Documentation/device-mapper/
> F: drivers/md/dm*
> F: drivers/md/persistent-data/
> F: include/linux/device-mapper.h
> F: include/linux/dm-*.h
> F: include/uapi/linux/dm-*.h
>
> NeilBrown
>
next prev parent reply other threads:[~2014-12-02 8:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-02 8:32 The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible? zhangxiao
2014-12-02 8:32 ` zhangxiao
2014-12-02 8:36 ` NeilBrown
2014-12-02 8:36 ` NeilBrown
2014-12-02 8:40 ` zhangxiao [this message]
2014-12-02 8:40 ` zhangxiao
-- strict thread matches above, loose matches on Subject: below --
2014-12-02 8:43 zhangxiao
2014-12-02 8:43 ` zhangxiao
2014-12-02 14:00 ` Mike Snitzer
2014-12-03 14:19 ` [dm-devel] " Joe Thornber
2014-12-03 16:17 ` Mike Snitzer
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=547D7B05.50406@windriver.com \
--to=xiao.zhang@windriver.com \
--cc=dm-devel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=neilb@suse.de \
/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.