From: NeilBrown <neilb@suse.de>
To: zhangxiao <xiao.zhang@windriver.com>
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 19:36:18 +1100 [thread overview]
Message-ID: <20141202193618.6d3adb22@notabene.brown> (raw)
In-Reply-To: <547D790E.3070803@windriver.com>
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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:
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
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next prev parent reply other threads:[~2014-12-02 8:36 UTC|newest]
Thread overview: 6+ 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 8:36 ` NeilBrown [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 14:00 ` Mike Snitzer
2014-12-03 14:19 ` [dm-devel] " Joe Thornber
2014-12-03 16:17 ` Mike Snitzer
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