[U-Boot] [PATCH V5 2/2] ext4fs write support

[uma.shankar at samsung.com]

Dear Wolfgang,
We have tested this feature on Samsung Boards using mmc interface. Here is a 
sample test run with exactly the same file size which you have used for 
testing

[Mon Aug 13 19:05:51.824 2012]  # ext4load mmc 0:6 0x40007fc0 abc.tar
[Mon Aug 13 19:05:51.846 2012] Loading file "abc.tar" from mmc device 0:6 
(dt)
[Mon Aug 13 19:05:53.087 2012] 33554432 bytes read
[Mon Aug 13 19:05:53.091 2012] #
Time taken 1.267s
=> 25.25 MiB/s

[Mon Aug 13 19:07:35.323 2012] # ext4load mmc 0:6 0x40007fc0 abc.tar
[Mon Aug 13 19:07:35.351 2012] Loading file "abc.tar" from mmc device 0:6 
(dt)
[Mon Aug 13 19:07:36.591 2012] 33554432 bytes read
[Mon Aug 13 19:07:36.595 2012] #
Time taken 1.272s
=> 25.15 MiB/s

I tried to look into ide interface implementation. It seems in case of ide 
(cmd_ide.c), "ide_read" function tries to read block by block.
Whereas in case of mmc interface, it has bulk read implementation where in 
multiple continuous blocks can be read in one shot.

Previous implementation of ext2 relies on block by block read, where as in 
current implementation multiple block read has been used. Thus, we are 
getting slow performance for ide in both the cases.

Note: I am using teraterm timestamp instead of date command to measure time.

Thanks & Regards,
Uma Shankar
--------------------------------------------------
From: "Wolfgang Denk" <wd at denx.de>
Sent: Monday, August 13, 2012 5:25 PM
To: "Uma Shankar" <uma.shankar at samsung.com>
Cc: "Manjunatha C Achar" <a.manjunatha at samsung.com>; 
<kim.phillips at freescale.com>; <u-boot at lists.denx.de>; "Hakgoo Lee" 
<goodguy.lee at samsung.com>; "Iqbal Shareef" <iqbal.ams at samsung.com>
Subject: Re: [U-Boot] [PATCH V5 2/2] ext4fs write support

> Dear Uma Shankar,
>
> In message <20120809215050.89DE220401A at gemini.denx.de> I wrote:
>>
>> Applied to "ext4" branch, thanks.
>
> I did some performance tests on a MPC5200 based board using the IDE
> interface (no DMA):
>
> => vers
>
> U-Boot 2012.07-00125-ged34f34 (Aug 10 2012 - 09:36:33)
> powerpc-linux-gcc (GCC) 4.6.4 20120303 (prerelease)
> GNU ld (GNU Binutils) 2.22
> => date ; ext2load ide 0:4 100000 usr-bin.tar 2000000 ; date
> Date: 2012-08-10 (Saturday)    Time: 16:27:21
> Loading file "usr-bin.tar" from ide device 0:4 hda4
> 33554432 bytes read
> Date: 2012-08-10 (Saturday)    Time: 16:27:48
>
> =================================================
>
> 27 seconds => 1.2 MiB/s
>
> => vers
>
> U-Boot 2012.07 (Aug 02 2012 - 10:31:44)
> powerpc-linux-gcc (GCC) 4.6.4 20120303 (prerelease)
> GNU ld (GNU Binutils) 2.22
> => date ; ext2load ide 0:4 100000 usr-bin.tar 2000000 ; date
> Date: 2012-08-10 (Saturday)    Time: 16:49:31
> Loading file "usr-bin.tar" from ide device 0:4 (hda4)
> 33554432 bytes read
> Date: 2012-08-10 (Saturday)    Time: 16:49:57
>
> =================================================
>
> 26 seconds => 1.2 MiB/s
>
>
> So within the accuracy of this measurement,the performance of the new
> code compared to the old ext2 code appears to be pretty much the same.
>
> Tested-by: Wolfgang Denk <wd at denx.de>
>
> Best regards,
>
> Wolfgang Denk
>
> -- 
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> Keep your eyes wide open before marriage, half shut afterwards.
>                                                 -- Benjamin Franklin