Re: [patch v11 00/13] extensible prctl task isolation interface and vmstat sync

From: Oscar Shiang
Date: Sat Feb 19 2022 - 03:02:59 EST


Hi Marcelo,

I tried to apply your patches to kernel v5.15.18-rt28 and measured
the latencies through oslat [1].

It turns out that the peak latency (around 100us) can drop to about 90us.
The result is impressive since I only changed the guest's kernel
instead of installing the patched kernel to both host and guest.

However, I am still curious about:
1) Why did I catch a bigger maximum latency in almost each of the
results of applying task isolation patches? Or does it come from
other reasons?
2) Why did we only get a 10us improvement on quiescing vmstat?

[1]: The result and the test scripts I used can be found at
https://gist.github.com/OscarShiang/8b530a00f472fd1c39f5979ee601516d#testing-task-isolation-via-oslat

Thanks,
Oscar