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> <br><br><div class="gmail_quote">On Fri, May 27, 2011 at 8:37 PM, Eduardo Silva <span dir="ltr"><<a href="mailto:edsiper@gmail.com">edsiper@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="im">On Fri, May 27, 2011 at 8:29 AM, mani <<a href="mailto:manishrma@gmail.com">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 class="im"><br></div></blockquote><div></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="im">
<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 href="http://edsiper.linuxchile.cl" target="_blank">http://edsiper.linuxchile.cl</a><br>
<a href="http://www.monkey-project.com" target="_blank">http://www.monkey-project.com</a><br>
</font></blockquote></div><br>