I'm interessted in getting the number of context switches a two processes in a KVM vm takes on a singel CPU over some time.
Earlier i have used perf, is this best practice?
And how much time is used on a context switch per CPU?
-
There are many publications about this topic. For example, Quantifying the cost of context switch. dl.acm.org/doi/abs/10.1145/1281700.1281702hakunami– hakunami2020-04-30 10:16:35 +00:00Commented Apr 30, 2020 at 10:16
Add a comment
|
1 Answer
About 1.2 microseconds which is about a thousand Cycles
answered Mar 15, 2019 at 22:19
-
And most of that time is taken up by the Linux scheduler doing its workJanKanis– JanKanis2020-06-12 06:29:14 +00:00Commented Jun 12, 2020 at 6:29
-
1000 cycles in 1.2 mics implies a processor frequency of 800mhz? This doesn't seem correct in 2019...nickt– nickt2024-07-24 10:15:34 +00:00Commented Jul 24, 2024 at 10:15
-
Wrong, the OP is asking about process context switch, not thread context switch. And even thread context switch costs about 30-300 us, if you take into account indirect costs like cache invalidation etc.Boris Burkov– Boris Burkov2025-03-03 06:59:45 +00:00Commented Mar 3 at 6:59