On Mon, 30 Sep 2024 08:57:26 -0700 Stephen Hemminger <[email protected]> wrote:
> > After placing counters all over the code, we realize that some threads are > > uniformly slow, in other words there is no application level issue that is > > throttling one thread over the other. We come to the conculsion that either > > the Cores on which they are running are not at the same frequency which > > seems doubtful or the threads are not getting a chance to execute on the > > cores uniformly. > > > > It seems that isolcpus has been deprecated in recent versions of linux. > > > > What is the recommended approach to prevent the kernel from utilizing some > > CPU threads, for anything other than the threads that are launched on them. > > > > On modern Linux systems, CPU isolation can be achieved with cgroups. Did you checkout the links in the section in the docs on core isolation. https://doc.dpdk.org/guides/linux_gsg/enable_func.html https://www.suse.com/c/cpu-isolation-practical-example-part-5/ https://www.rcannings.com/systemd-core-isolation/ There is also a much more complex and detailed script which is part of the open source project DanOs here: https://github.com/danos/vyatta-cpu-shield/blob/master/usr/bin/cpu_shield If you really want isolated CPU's you have to some more complex stuff to make sure interrupts etc don't run on that CPU. Also never use CPU 0
