On 26 January 2018 at 08:14, Steve McIntyre <steve.mcintyre@linaro.org> wrote:

On Fri, Jan 26, 2018 at 02:04:52PM +0000, Florence ROUGER JUNG wrote:
>That's right, at first I used following command  and there was some output  to the terminal
>       iozone $OPT -f /mnt_emmc/tmp/iozone.tmp | tee result.log
>
>But now I redirect output
>       iozone $OPT -f /mnt_emmc/tmp/iozone.tmp > iozone.log 2>&1
>performance are better but remain not homogeneous with Lava

OK, that does surprise me. I could imagine that running a test with
lots of output to the serial port could slow things down, but if
you're redirecting everything then it should be making no difference
at all. What kind of variance are you seeing?

I've been working on a long test run definition with a lot of serial console output (Piglit), here is what i found [1],  looks like is related to this thread.