From: zhangxiao <xiao.zhang@windriver.com>
To: device-mapper development <dm-devel@redhat.com>,
linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
agk@redhat.com
Subject: Re: [dm-devel] The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible?
Date: Thu, 4 Dec 2014 09:26:19 +0800 [thread overview]
Message-ID: <547FB83B.8080401@windriver.com> (raw)
In-Reply-To: <20141203141921.GB6993@debian>
On 2014年12月03日 22:19, Joe Thornber wrote:
> On Tue, Dec 02, 2014 at 09:00:17AM -0500, Mike Snitzer wrote:
>> On Tue, Dec 02 2014 at 3:43am -0500,
>> zhangxiao <xiao.zhang@windriver.com> wrote:
>>
>>> Hi Experts,
>>>
>>> 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?
>>
>> No immediate plans.
>
> That hash table has been replaced with a red/black tree.
>
> https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-for-3.19&id=4e420c452b11edf9d510c8180ac66f529e5b6206
>
>
Great Thanks!
Best Regards
Xiao
WARNING: multiple messages have this Message-ID (diff)
From: zhangxiao <xiao.zhang@windriver.com>
To: device-mapper development <dm-devel@redhat.com>,
<linux-raid@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<agk@redhat.com>
Subject: Re: [dm-devel] The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible?
Date: Thu, 4 Dec 2014 09:26:19 +0800 [thread overview]
Message-ID: <547FB83B.8080401@windriver.com> (raw)
In-Reply-To: <20141203141921.GB6993@debian>
On 2014年12月03日 22:19, Joe Thornber wrote:
> On Tue, Dec 02, 2014 at 09:00:17AM -0500, Mike Snitzer wrote:
>> On Tue, Dec 02 2014 at 3:43am -0500,
>> zhangxiao <xiao.zhang@windriver.com> wrote:
>>
>>> Hi Experts,
>>>
>>> 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?
>>
>> No immediate plans.
>
> That hash table has been replaced with a red/black tree.
>
> https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-for-3.19&id=4e420c452b11edf9d510c8180ac66f529e5b6206
>
>
Great Thanks!
Best Regards
Xiao
next prev parent reply other threads:[~2014-12-04 1:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-02 8:43 The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible? 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
2014-12-04 1:26 ` zhangxiao [this message]
2014-12-04 1:26 ` [dm-devel] " zhangxiao
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