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Diffstat (limited to 'cddl/contrib/dtracetoolkit/Examples/priclass_example.txt')
| -rw-r--r-- | cddl/contrib/dtracetoolkit/Examples/priclass_example.txt | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/cddl/contrib/dtracetoolkit/Examples/priclass_example.txt b/cddl/contrib/dtracetoolkit/Examples/priclass_example.txt new file mode 100644 index 0000000..bf63e09 --- /dev/null +++ b/cddl/contrib/dtracetoolkit/Examples/priclass_example.txt @@ -0,0 +1,82 @@ +The following is a demonstration of the priclass.d script. + + +The script was run for several seconds then Ctrl-C was hit. During +this time, other processes in different scheduling classes were +running. + + # ./priclass.d + Sampling... Hit Ctrl-C to end. + ^C + + IA + value ------------- Distribution ------------- count + 40 | 0 + 50 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 30 + 60 | 0 + + SYS + value ------------- Distribution ------------- count + < 0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 4959 + 0 | 0 + 10 | 0 + 20 | 0 + 30 | 0 + 40 | 0 + 50 | 0 + 60 | 30 + 70 | 0 + 80 | 0 + 90 | 0 + 100 | 0 + 110 | 0 + 120 | 0 + 130 | 0 + 140 | 0 + 150 | 0 + 160 | 50 + >= 170 | 0 + + RT + value ------------- Distribution ------------- count + 90 | 0 + 100 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 110 + 110 | 0 + + TS + value ------------- Distribution ------------- count + < 0 | 0 + 0 |@@@@@@@@@@@@@@@ 2880 + 10 |@@@@@@@ 1280 + 20 |@@@@@ 990 + 30 |@@@@@ 920 + 40 |@@@@ 670 + 50 |@@@@ 730 + 60 | 0 + +The output is quite interesting, and illustrates neatly the behaviour +of different scheduling classes. + +The IA interactive class had 30 samples of a 50 to 59 priority, a fairly +high priority. This class is used for interactive processes, such as +the windowing system. I had clicked on a few windows to create this +activity. + +The SYS system class has had 4959 samples at a < 0 priority - the lowest, +which was for the idle thread. There are a few samples at higher +priorities, including some in the 160 to 169 range (the highest), which +are for interrupt threads. The system class is used by the kernel. + +The RT real time class had 110 samples in the 100 to 109 priority range. +This class is designed for real-time applications, those that must have +a consistant response time regardless of other process activity. For that +reason, the RT class trumps both TS and IA. I created these events by +running "prstat -R" as root, which runs prstat in the real time class. + +The TS time sharing class is the default scheduling class for the processes +on a Solaris system. I ran an infinite shell loop to create heavy activity, +"while :; do :; done", which shows a profile that leans towards lower +priorities. This is deliberate behaivour from the time sharing class, which +reduces the priority of CPU bound processes so that they interefere less +with I/O bound processes. The result is more samples in the lower priority +ranges. |
