SATA performance degradation

[myungjukim]

Hi, Community

I've update kernel 3.14.28 to 3.14.52 recently. I've connect hdd(2T) to sata interface.

but I've found performance degradation regardless which format have with sata hdd read/write test.

Result is HUGE degradation between 3.14.28 and 3.14.52. How to remove SATA degradation point ?

<test>

file system is based on ext4. bsp is commercial.

cpu : imx6dual

command : iozone -a -n 4096m -g 4096m -i 0 -i 1 -f /mnt/HDD1/iozone.tmpfile -Rb ./iozone

<test result>

- 3.14.28 kernel : write 100Mb/s, read 120Mb/s

- 3.14.52 kernel : write15Mb/s, read 60Mb/s

[igorpadykov]

Hi Christian 

could you try nxp L3.14.52 bsp

http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/arch/arm/mach-imx?h=imx_3.14.52_1.1...

for non-nxp bsps one can post on  meta-fsl-arm mailing list, so that someone familiar with

it could try to assist you

meta-freescale Info Page 

Best regards
igor
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[myungjukim]

Hi, igor

I'm using nxp official bsp on your  document. I think correct download bsp.

         Freescale Yocto Project User's Guide, Rev. 0, 12/2015 , page 13

         repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-3.14.52-1.1.0_ga

I think, It is not file system issue. It is lower access speed to the SATA controller integrated into the main CPU/SoC.

I've download your 4.1.15 bsp and test it. It's speed  is write 12.5 MB/s and read 42 MB/s .

I get same result on your reference board(imx6q_sabresd).

Best Regards

[igorpadykov]

Hi Christian 

please check

https://community.nxp.com/message/859275

Best regards
igor