Re: Raid 5 Read performance

["Majed B." <majedb@gmail.com>]

All kernel changes are mentioned in the changelogs, so I think you can
find what you want at kernel.org -- it also mentions who did the
change, so you can contact him/her directly.

I'm not saying you won't find help here, but the aforementioned is a
better chance :)

On Fri, Sep 11, 2009 at 6:48 PM, satha kottidi<satha_koti@yahoo.co.in> wrote:
> Hi Majed & All,
>
> Yes we two are working together. Actually we found a change in md/raid5.c
> file in the function sync_request() it restricts the numbers, the kernel
> 2.6.27 has code like this
>
> while(unlikely(!handle_stripe(sh, NULL)))
>                 ;
>  But in kernel 2.6.21 it simply the handle_stripe(sh, NULL) call.
>
> Can anybody tell me the necessity of the change, and why it reduces the
> numbers. Any comments is very helpful for me to analyze the driver further.
>
>
> Thanks,
> Satha.
>
> --- On Fri, 11/9/09, Majed B. <majedb@gmail.com> wrote:
>
> From: Majed B. <majedb@gmail.com>
> Subject: Re: Raid 5 Read performance
> To: "Koti" <satha_koti@yahoo.co.in>
> Cc: linux-raid@vger.kernel.org
> Date: Friday, 11 September, 2009, 1:47 AM
>
> Someone else has already emailed the mailing list about this. Are you
> two running an assignment or something?!
>
> Check the mailing list archive for whatever people have already replied
> with.
>
> On Thu, Sep 10, 2009 at 11:07 PM, Koti<satha_koti@yahoo.co.in> wrote:
>> Hi All
>>
>> I am trying measure the RAID 5 Read numbers on linux kernel-2.6.21 and
>> kernel 2.6.27 the numbers are lower on later kernel (2.6.27). Iam
>> measuring
>> the numbers using "time dd" command (4GB ). Is any valid reason for this,
>> or
>> Am missing anything in the process. Can anybody help me in analyze this
>> problem.
>>
>> Thanks,
>> Koti
>>
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>
>
>
> --
>        Majed B.
>
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-- 
       Majed B.
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