Comment 12 for bug 1027203

I have suspected strace output problem on ubuntu and carried out few experiments to confirm the behavior.
expected sysfs output is coming on EXP-1 and EXP-2. but not incase of EXP-3, EXP-4 and EXP-5

Regarding the EXP-1 and EXP-2 test
        with strace switching is happening.
        without strace switching is happening.

Regarding the EXP-3, EXP-4 and EXP-5 test
        with strace switching is not happening.
        without strace switching is happening.
The above behavior is confirmed by amit pundir, he has GUI FM where we can see cluster blinks.

EXP 1:
#cd /usr/bin
#strace -f /usr/bin/sh governor
open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 3
write(1, "userspace\n", 10) = 10
[pid 1970] open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", O_RDONLY|O_LARGEFILE) = 3
[pid 1970] read(3, "userspace\n", 32768) = 10

File not found error we can ignore from the strace output.
After above open() read() and write() operations, still strace reported governor file not found several times.

[pid 1968] write(2, "[[: not found", 13[[: not found) = 13
[pid 1968] write(2, "\n", 1

EXP 2:
#strace -f /usr/bin/sh /usr/bin/run_stress_switcher_test.sh -b (run-bl-basic-tests.sh and switcher-tests.sh )
rmmod arm-bl-cpufreq
[pid 1427] open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = -1 ENOENT (No such file or directory)
...
insmod arm-bl-cpufreq
[pid 1503] open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 3
[pid 1503] write(1, "1000000\n", 8) = 8

EXP 3:
#strace -f /usr/bin/sh /usr/bin/run_stress_switcher_test.sh -t 1 (test name cache-coherency-a7 )

EXP 4:
#strace -f /usr/bin/sh /usr/bin/run_stress_switcher_test.sh -t 2 (test name cache-coherency-a15 )

EXP 5:
#strace -f /usr/bin/sh /usr/bin/run_stress_switcher_test.sh -t 3 (test name cache-coherency-switching )