Re: [PATCH] KVM test: Memory ballooning test for KVM guest

[pradeep <psuriset@linux.vnet.ibm.com>]

sudhir kumar wrote:

> On Fri, Apr 9, 2010 at 2:40 PM, pradeep <psuriset@linux.vnet.ibm.com> wrote:
>   
>> Hi Lucas
>>
>> Thanks for your comments.
>> Please find the patch, with suggested changes.
>>
>> Thanks
>> Pradeep
>>
>>
>>
>> Signed-off-by: Pradeep Kumar Surisetty <psuriset@linux.vnet.ibm.com>
>> ---
>> diff -uprN autotest-old/client/tests/kvm/tests/balloon_check.py
>> autotest/client/tests/kvm/tests/balloon_check.py
>> --- autotest-old/client/tests/kvm/tests/balloon_check.py        1969-12-31
>> 19:00:00.000000000 -0500
>> +++ autotest/client/tests/kvm/tests/balloon_check.py    2010-04-09
>> 12:33:34.000000000 -0400
>> @@ -0,0 +1,47 @@
>> +import re, string, logging, random, time
>> +from autotest_lib.client.common_lib import error
>> +import kvm_test_utils, kvm_utils
>> +
>> +def run_balloon_check(test, params, env):
>> +    """
>> +    Check Memory ballooning:
>> +    1) Boot a guest
>> +    2) Increase and decrease the memory of guest using balloon command from
>> monitor
>>     
> Better replace this description by "Change the guest memory between X
> and Y values"
> Also instead of using 0.6 and 0.95 below, better use two variables and
> take their value from config file. This will give the user a
> flexibility to narrow or widen the ballooning range.
>   
Thanks for your suggestions. I dont  think, user should need flexibility 
here.
If ballooning doest work for one set of value, it will not work for any 
other.
And here, we are choosing between 60 to 95% of actual values, which is 
reasonable.

>   
>> +    3) check memory info
>> +
>> +    @param test: kvm test object
>> +    @param params: Dictionary with the test parameters
>> +    @param env: Dictionary with test environment.
>> +    """
>> +
>> +    vm = kvm_test_utils.get_living_vm(env, params.get("main_vm"))
>> +    session = kvm_test_utils.wait_for_login(vm)
>> +    fail = 0
>> +
>> +    # Check memory size
>> +    logging.info("Memory size check")
>> +    expected_mem = int(params.get("mem"))
>> +    actual_mem = vm.get_memory_size()
>> +    if actual_mem != expected_mem:
>> +        logging.error("Memory size mismatch:")
>> +        logging.error("Assigned to VM: %s" % expected_mem)
>> +        logging.error("Reported by OS: %s" % actual_mem)
>> +
>> +    #change memory to random size between 60% to 95% of actual memory
>> +    percent = random.uniform(0.6, 0.95)
>> +    new_mem = int(percent*expected_mem)
>> +    vm.send_monitor_cmd("balloon %s" %new_mem)
>>     
>
> You may want to check if the command passed/failed. Older versions
> might not support ballooning.
>   

sure,  i will make changes here.
>   
>> +    time.sleep(20)
>>     
> why 20 second sleep and why the magic number?
>   
As soon as balloon command is passed, it takes some time for memory 
ballooing.
If we check "info balloon" as soon as we run ballooning, it will give 
weird values.
I just choose it as, 20sec and its not huge time from testing perspective.
>   
>> +    status, output = vm.send_monitor_cmd("info balloon")
>>     
> You might want to put this check before changing the memory.
>
>   
sure, will make changes here too.
>> +    if status != 0:
>> +        logging.error("qemu monitor command failed: info balloon")
>> +
>> +    balloon_cmd_mem = int(re.findall("\d+",output)[0])
>>     
> A better variable name I can think of is "ballooned_mem"
>   

will  change it...
>   
>> +    if balloon_cmd_mem != new_mem:
>> +        logging.error("memory ballooning failed while changing memory to
>> %s" %balloon_cmd_mem)
>> +       fail += 1
>> +
>> +    #Checking for test result
>> +    if fail != 0:
>>     
> In case you are running multiple iterations and the 2nd iteration
> fails you will always miss this condition.
>   

>   
>> +        raise error.TestFail("Memory ballooning test failed ")
>> +    session.close()
>> diff -uprN autotest-old/client/tests/kvm/tests_base.cfg.sample
>> autotest/client/tests/kvm/tests_base.cfg.sample
>> --- autotest-old/client/tests/kvm/tests_base.cfg.sample 2010-04-09
>> 12:32:50.000000000 -0400
>> +++ autotest/client/tests/kvm/tests_base.cfg.sample     2010-04-09
>> 12:53:27.000000000 -0400
>> @@ -185,6 +185,10 @@ variants:
>>                 drift_threshold = 10
>>                 drift_threshold_single = 3
>>
>> +    - balloon_check:  install setup unattended_install boot
>> +        type = balloon_check
>> +        extra_params += " -balloon virtio"
>> +
>>     - stress_boot:  install setup unattended_install
>>         type = stress_boot
>>         max_vms = 5
>> ---
>>     
>
> Rest all looks good!!!!
>   
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>>     
>
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