On 06/15/2011 02:57 AM, Avi Kivity wrote:
> Okay. If you do anything interesting with it, please let us know. I
> only tested the watchdog, 'perf top', and 'perf stat'.
>
For the following I was using the userspace command from latest
perf-core branch.
cycles H/W event is not working for me, so perf-top did not do much
other than start.
perf-stat -ddd shows a whole lot of 0's - which is interesting. It means
time enabled and time running are non-0, yet the counter value is 0.
cycles and instructions events also show as not counted
Command I was playing with:
taskset -c 1 chrt -r 1 perf stat -ddd openssl speed aes
Performance counter stats for 'openssl speed aes':
46111.369065 task-clock # 0.984 CPUs utilized
195 context-switches # 0.000 M/sec
0 CPU-migrations # 0.000 M/sec
650 page-faults # 0.000 M/sec
<not counted> cycles
0 stalled-cycles-frontend # 0.00% frontend cycles
idle [ 7.63%]
0 stalled-cycles-backend # 0.00% backend cycles
idle [12.70%]
<not counted> instructions
801,002,999 branches # 17.371 M/sec
[ 8.15%]
8,491,676 branch-misses # 1.06% of all branches
[15.17%]
0 L1-dcache-loads # 0.000 M/sec
[ 9.23%]
0 L1-dcache-load-misses # 0.00% of all L1-dcache
hits [ 8.48%]
0 LLC-loads # 0.000 M/sec
[13.89%]
0 LLC-load-misses # 0.00% of all LL-cache
hits [12.47%]
0 L1-icache-loads # 0.000 M/sec
[ 9.46%]
0 L1-icache-load-misses # 0.00% of all L1-icache
hits [ 9.44%]
0 dTLB-loads # 0.000 M/sec
[ 9.59%]
0 dTLB-load-misses # 0.00% of all dTLB
cache hits [11.00%]
0 iTLB-loads # 0.000 M/sec
[11.13%]
0 iTLB-load-misses # 0.00% of all iTLB
cache hits [ 9.73%]
0 L1-dcache-prefetches # 0.000 M/sec
[10.98%]
0 L1-dcache-prefetch-misses # 0.000 M/sec
[12.51%]
46.851192693 seconds time elapsed
Also, the numbers for branches and branch-misses just seem wrong
compared to the same command run in the host as well as running
perf-stat in the host on the vcpu thread running openssl (with the vcpu
pinned to a pcpu).
And then reality kicked in and I had to move on to other items.
David
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