CPU Count

[tylerharter]

When I walk through the tutorial, the example seems to assume I have more cores than I actually do, leading to the following exception:

======================================================================
ERROR: test_run (tests.test_demo.Test_TraceAndSimulateLinuxDD)

Traceback (most recent call last):
File "tests/test_demo.py", line 28, in test_run
obj.main()
File "config_helper/experiment.py", line 235, in main
self.run()
File "config_helper/experiment.py", line 226, in run
run_workflow(self.conf)
File "workflow.py", line 14, in run_workflow
wf.run()
File "workflow.py", line 23, in run
event_iter = self._run_workload()
File "workflow.py", line 43, in _run_workload
event_iter = runner.run()
File "workrunner/wlrunner.py", line 168, in run
return self.run_with_blktrace()
File "workrunner/wlrunner.py", line 202, in run_with_blktrace
cpuhandler.set_cpus(self.conf['n_online_cpus'])
File "workrunner/cpuhandler.py", line 69, in set_cpus
enable_all_cpus()
File "workrunner/cpuhandler.py", line 62, in enable_all_cpus
enable_n_cpus(len(possible_cpus))
File "workrunner/cpuhandler.py", line 93, in enable_n_cpus
switch_cpu(cpuid, 'ON')
File "workrunner/cpuhandler.py", line 53, in switch_cpu
f = open(path, 'w')
IOError: [Errno 2] No such file or directory: '/sys/devices/system/cpu/cpu8/online'

[tylerharter]

I only have 8 cores, so /sys/devices/system/cpu/cpu7/online exists, but /sys/devices/system/cpu/cpu8/online does not.

[junhe]

Weird, I thought I automatically detected number of core... Will check it later.

[luminus7]

same problem here
Environment: 14.04 Ubuntu, 4.5.4 kernel
cpu: i5-8500 with 6cores

IOError: [Errno 2] No such file or directory: '/sys/devices/system/cpu/cpu6/online'
occured in every last line of error

attached file is log after $make test_all
wiscsim error 'cpu'.txt

[junhe]

How many cores do you have? Could you do
$ ls /sys/devices/system/cpu/

[luminus7]

got 6 cores in my pc

~$ ls /sys/devices/system/cpu/
cpu0 cpu2 cpu4 cpufreq isolated microcode offline possible present
cpu1 cpu3 cpu5 cpuidle kernel_max modalias online power uevent

[junhe]

Also, do the following?

$ cat /sys/devices/system/cpu/online

[luminus7]

sure!
~$ cat /sys/devices/system/cpu/online
0-5

[junhe]

I think the cause of the failure is that /sys/devices/system/cpu/possible contains CPU id 6, but there is actually no CPU 6. To workaround, try change get_possible_cpus() ( https://github.com/junhe/wiscsee/blob/e0f086b04230747205056d8f4def42f9eb36c8d2/workrunner/cpuhandler.py#L4) to def get_possible_cpus(): return range(0, 6) I hope this works for you..

…

On Mon, Feb 17, 2020 at 10:58 PM luminus7 ***@***.***> wrote: sure! ~$ cat /sys/devices/system/cpu/online 0-5 — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#8?email_source=notifications&email_token=AAEZ6JIFBYVIO3VP5LNJAL3RDNTIJA5CNFSM4EEKZ2F2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEMASUCQ#issuecomment-587278858>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEZ6JL5IXRVK6PDQQHRISDRDNTIJANCNFSM4EEKZ2FQ> .

[luminus7]

~$ cat /sys/devices/system/cpu/possible
0-7

in wiscsee/workrunner/cpuhandler.py

def get_possible_cpus():
    f = open("/sys/devices/system/cpu/possible", 'r')
    line = f.readline()
    f.close()

    # assuming format of 0-2,4,6-63
    items = line.split(',')
    cpus = []
    for item in items:
        if '-' in item:
            a,b = item.split('-')
            a = int(a)
            b = int(b)
            cpus.extend(range(a, b+1))
        else:
            cpus.append(int(item))

#    return cpus
    return range(0,6)

this make successful test_all, and run_demo

thank you for your fast and kind respond :)

[junhe]

:)

…

On Tue, Feb 18, 2020 at 8:32 PM luminus7 ***@***.***> wrote: ~$ cat /sys/devices/system/cpu/possible 0-7 in wiscsee/workrunner/cpuhandler.py def get_possible_cpus(): f = open("/sys/devices/system/cpu/possible", 'r') line = f.readline() f.close() # assuming format of 0-2,4,6-63 items = line.split(',') cpus = [] for item in items: if '-' in item: a,b = item.split('-') a = int(a) b = int(b) cpus.extend(range(a, b+1)) else: cpus.append(int(item)) # return cpus return range(0,6) this make successful test_all, and run_demo thank you for your fast and kind respond :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#8?email_source=notifications&email_token=AAEZ6JPAHVL4PUVTOIQVI3TRDSK4HA5CNFSM4EEKZ2F2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEMGDWDQ#issuecomment-588004110>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEZ6JN3HOAXE3PZAWD2OI3RDSK4HANCNFSM4EEKZ2FQ> .