MX6Q SATA read speed gets worse in linux 3.14.52_1.1.0 BSP

[Danube]

Hi All,

SSD device is INTEL SSDSA2CT040G3.

The test commad i use on target board:

echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Write test command:

dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fsync

Read test command:

dd if=tempfile of=/dev/null bs=1M count=1024

Test Result: (Rootfs is buildroot)

linux 3.14.52:

Write:

1073741824 bytes (1.0GB) copied, 26.856296 seconds, 38.1MB/s

Read:

1073741824 bytes (1.0GB) copied, 13.097736 seconds, 78.2MB/s

linux 3.10.53:

Write:

1073741824 bytes (1.0GB) copied, 28.990223 seconds, 35.3MB/s

Read:

1073741824 bytes (1.0GB) copied, 8.182314 seconds, 125.1MB/s

linux 3.0.35:

Write:

1073741824 bytes (1.0GB) copied, 36.756555 seconds, 27.9MB/s

Read:

1073741824 bytes (1.0GB) copied, 10.264888 seconds, 99.8MB/s

As you see, the read speed is 30% worse in linux 3.14.52 then linux 3.10.53.

Any idea ?

Is Any patch code for SATA performance improve ?

Apollo Chang

[igorpadykov]

Hi Appolo

what board used in the case. Could you try to measure on Sabre reference board

running fsl-image-machine-test image without gui and multimedia.

May be useful to check core load with top commands :

http://unix.stackexchange.com/questions/41311/cpu-and-core-usage-stats

also measure the bus load with MMDC profiling tool in unit tests ../mmdc/mmdc.c

I am not aware of official sata performance numbers, believe you can request it

through local fae channel.

Best regards

igor

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