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Diffstat (limited to 'cddl/contrib/dtracetoolkit/Examples/dispqlen_example.txt')
| -rw-r--r-- | cddl/contrib/dtracetoolkit/Examples/dispqlen_example.txt | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/cddl/contrib/dtracetoolkit/Examples/dispqlen_example.txt b/cddl/contrib/dtracetoolkit/Examples/dispqlen_example.txt new file mode 100644 index 000000000000..f3542c00ea82 --- /dev/null +++ b/cddl/contrib/dtracetoolkit/Examples/dispqlen_example.txt @@ -0,0 +1,62 @@ +This is a demonstration of the dispqlen.d script, + + +Here we run it on a single CPU desktop, + + # dispqlen.d + Sampling... Hit Ctrl-C to end. + ^C + CPU 0 + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1790 + 1 |@@@ 160 + 2 | 10 + 3 | 0 + +The output shows the length of the dispatcher queue is mostly 0. This is +evidence that the CPU is not very saturated. It does not indicate that the +CPU is idle - as we are measuring the length of the queue, not what is +on the CPU. + + + +Here it is run on a multi CPU server, + + # dispqlen.d + Sampling... Hit Ctrl-C to end. + ^C + CPU 1 + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1573 + 1 |@@@@@@@@@ 436 + 2 | 4 + 3 | 0 + + CPU 4 + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@@@@@@@@@@@@@@@ 1100 + 1 |@@@@@@@@@@@@@@@@@@ 912 + 2 | 1 + 3 | 0 + + CPU 0 + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@@@@@@@@@@ 846 + 1 |@@@@@@@@@@@@@@@@@@@@@@@ 1167 + 2 | 0 + + CPU 5 + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@ 397 + 1 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1537 + 2 |@@ 79 + 3 | 0 + +The above output shows that threads are queueing up on CPU 5 much more than +CPU 0. + |