<div dir="ltr"><div><div><div><div>Hi, all:<br><br>I was trying to run some experiments in Litmus in a VM. However, all the number I got was negative for the task lateness.<br></div><div>And all jobs are showing 0 for the period, and shows CPU=-1.<br>
</div><div><br>here is my setup:<br></div>HostOS: Normal Linux 3.4.35<br></div>Xen: 4.1.4<br></div>GuestOS: root@litmus1:~# uname -a<br>Linux litmus1 3.0.0-litmus #3 SMP PREEMPT Wed Apr 17 11:02:36 CDT 2013 x86_64 x86_64 x86_64 GNU/Linux<br>
<br></div>Here is the scripts to run experiments: <br>root@litmus1:~# cat 200_1_MPR_Dom1.sh <br>rtspin -s 0.98 8 10 100 &<br>rtspin -s 0.98 8 10 100 &<br>rtspin -s 0.98 8 10 100 &<br>rtspin -s 0.98 8 10 100 &<br>
rtspin -s 0.98 8 10 100 &<br>st_trace 200_1_MPR_Dom1 <br>killall rtspin<br><br><div>I modified the st_trace so it stopped after 20 seconds. This is the only modification I made.<br></div><div>Here is the script output:<br>
root@litmus1:~# ./200_1_MPR_Dom1.sh <br>CPU 0: 1382 > st-200_1_MPR_Dom1-0.bin [0]<br>CPU 1: 1383 > st-200_1_MPR_Dom1-1.bin [0]<br>CPU 2: 1384 > st-200_1_MPR_Dom1-2.bin [0]<br>CPU 3: 1385 > st-200_1_MPR_Dom1-3.bin [0]<br>
CPU 4: 1386 > st-200_1_MPR_Dom1-4.bin [0]<br>Press Enter to end tracing...<br>Ending Trace...<br>Disabling 10 events.<br>Disabling 10 events.<br>Disabling 10 events.<br>Disabling 10 events.<br>Disabling 10 events.<br>[10462.657790] Failed trace writes: 0<br>
/dev/litmus/sched_trace3: 192096 bytes read.<br>[10462.658101] Failed trace writes: 0<br>/dev/litmus/sched_trace1: 192096 bytes read.<br>[10462.663359] Failed trace writes: 0<br>/dev/litmus/sched_trace0: 192120 bytes read.<br>
[10462.663989] Failed trace writes: 0<br>/dev/litmus/sched_trace4: 192168 bytes read.<br>[10462.665088] Failed trace writes: 0<br>/dev/litmus/sched_trace2: 192168 bytes read.<br><br></div><div>However, here is the result using st_job_stats<br>
root@litmus1:~# st_job_stats st-200_1_MPR_Dom1-0.bin | head<br># Task, Job, Period, Response, DL Miss?, Lateness, Tardiness<br># task NAME=<unknown> PID=1369 COST=0 PERIOD=0 CPU=-1<br> 1369, 509, 0, 7900519, 0, -2099481, 0<br>
1369, 510, 0, 7895709, 0, -2104291, 0<br> 1369, 511, 0, 7893512, 0, -2106488, 0<br> 1369, 512, 0, 7898799, 0, -2101201, 0<br>
1369, 513, 0, 7902469, 0, -2097531, 0<br> 1369, 514, 0, 7902914, 0, -2097086, 0<br> 1369, 515, 0, 7894691, 0, -2105309, 0<br>
1369, 516, 0, 7897107, 0, -2102893, 0<br><br></div><div>And the data on other cpus shows the same negative value for lateness..<br></div><div><br><br></div><div>In Xen, I am using tsc_mode=1, which is:<br>
- tsc_mode=1 (always emulate). All rdtsc instructions are emulated;<br> this is the best choice when TSC-sensitive apps are running and<br> it is necessary to understand worst-case performance degradation<br> for a specific hardware environment.<br>
<br></div><div>this should be good for tsc-sensitive applications..<br><br></div><div>Any ideas?<br><br>Thanks very much!<br><br>Sisu<br></div><div><br></div><div><br><br></div><div> <br></div><div><div><div><div><br clear="all">
<div><br>-- <br>Sisu Xi, PhD Candidate<br><br><a href="http://www.cse.wustl.edu/~xis/" target="_blank">http://www.cse.wustl.edu/~xis/</a><br>Department of Computer Science and Engineering<br>Campus Box 1045<br>Washington University in St. Louis<br>
One Brookings Drive<br>St. Louis, MO 63130
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