We are doing a performance test on an oci(oracle cloud) instance with ‘ht(hyper threading)’ enabled.
We are currently testing the file system pipeline
I read the blog below.
If I disable the instance ‘ht’
I wonder if it will have a good effect on the ongoing test.
Also, what does ‘ht’ affect the function of memsql?
I recall that the perf approach to off-cpu flamegraphs can be problematic because of the cpu time overhead and because some of the command line arguments involved have changed over kernel versions.
If you have a kernel recent enough to support bpf, I’d recommend instead using the offcputime script from this repository: GitHub - iovisor/bcc: BCC - Tools for BPF-based Linux IO analysis, networking, monitoring, and more to produce off-cpu flamegraphs, as described in Linux eBPF Off-CPU Flame Graph .
I can’t personally give a blanket recommendation about hyperthreading. Testing it with your workload is a good idea.
I do want to note, however, that off-cpu flamegraphs are probably not relevant to hyperthreading. Hyperthreading will affect the throughput of threads that are running (and sharing the resources of a single CPU), but shouldn’t directly affect how much time they spend in a non-running state, which is what off-cpu flamegraphs measure.