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On 06/02/2011 05:41 AM, mani wrote:
<blockquote
cite="mid:BANLkTinbMfmF1m_vA6RiP5Y-dnOueyOKwg@mail.gmail.com"
type="cite">Dear All,<br>
<br>
Any suggestions on the below point ? <br>
</blockquote>
<br>
have you tried different benchmarks?<br>
This can give you an idea of the impact. It seems that up to now,
you've only executed sequential read and write access by one
process.<br>
<br>
Personally I use the fio benchmark. For flash file systems, David
Wagner from Free Electrons developed a benchmarksuite. Maybe it
would be worse having a look on it.<br>
<br>
Best regards,<br>
Matthias Brugger<br>
<br>
<blockquote
cite="mid:BANLkTinbMfmF1m_vA6RiP5Y-dnOueyOKwg@mail.gmail.com"
type="cite"><br>
Thanks in advance.. <br>
<br>
<div class="gmail_quote">On Mon, May 30, 2011 at 10:53 AM, mani <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:manishrma@gmail.com">manishrma@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">Dear Eduardo,<br>
<br>
I am using squashfs filesystem. So i am more concern with
the read speed.<br>
whereas below are the details <br>
read
speed write speed <br>
ELEVATOR_INSERT_SORT 8 MBps 5MBps<br>
ELEVATOR_INSERT_BACK 10 MBps 7.2MBps<br>
<br>
used the following command for measurement for both the
cases. <br>
reading <br>
hdparm -t /dev/mtdblock3<br>
<br>
writing <br>
dd if=/dev/zero of=/dev/mtd3 bs=4096 count=100k <br>
<br>
As of now everything is working fine with those changes <br>
but i am worried if these changes would have any adverse
effect anywhere ? <br>
<br>
Thanks. <br>
<div>
<div class="h5"> <br>
<br>
<div class="gmail_quote">On Fri, May 27, 2011 at 8:37 PM,
Eduardo Silva <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:edsiper@gmail.com" target="_blank">edsiper@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt
0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div>On Fri, May 27, 2011 at 8:29 AM, mani <<a
moz-do-not-send="true"
href="mailto:manishrma@gmail.com" target="_blank">manishrma@gmail.com</a>>
wrote:<br>
><br>
> Dear All,<br>
><br>
> I am working on linux kernel 2.6.32.9 tegra
NVIDIA board.<br>
><br>
> I am getting ~8MBps speed of the Nand disk if i
use hdparm<br>
> hdparm -t /dev/mtdblock3<br>
><br>
> i made changes in block layer of kernel as
below:-<br>
><br>
> block/blk-core.c<br>
> static inline void add_request(struct
request_queue *q, struct request *req)<br>
> {<br>
> drive_stat_acct(req, 1);<br>
><br>
> /*<br>
> * elevator indicated where it wants
this request to be<br>
> * inserted at elevator_merge time<br>
> */<br>
><br>
> __elv_add_request(q, req,
ELEVATOR_INSERT_BACK, 0);<br>
> //__elv_add_request(q, req,
ELEVATOR_INSERT_SORT, 0);<br>
> }<br>
><br>
><br>
<br>
</div>
What are the results for read and write for both cases
?<br>
<div><br>
</div>
</blockquote>
<blockquote class="gmail_quote" style="margin: 0pt 0pt
0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div>
<br>
> changed ELEVATOR_INSERT_SORT to
ELEVATOR_INSERT_BACK<br>
> it improves my NAND speed to 10MBps.<br>
><br>
> I am using "noop" I/O scheduler.<br>
><br>
> Will this change have any adverse effect in
kernel ? or any other side<br>
> effect as far as i am using only Nand no Hard
disk.<br>
><br>
><br>
> Thanks<br>
> Mani<br>
><br>
><br>
</div>
> _______________________________________________<br>
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><br>
><br>
<font color="#888888"><br>
<br>
<br>
--<br>
Eduardo Silva<br>
<a moz-do-not-send="true"
href="http://edsiper.linuxchile.cl"
target="_blank">http://edsiper.linuxchile.cl</a><br>
<a moz-do-not-send="true"
href="http://www.monkey-project.com"
target="_blank">http://www.monkey-project.com</a><br>
</font></blockquote>
</div>
<br>
</div>
</div>
</blockquote>
</div>
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