Hi, Daniel, On Wed, Mar 17, 2021 at 08:49:03AM +0100, Daniel Wagner wrote: > On Tue, Mar 16, 2021 at 04:07:05PM -0400, Peter Xu wrote: > > I think what I'm missing is why we had such a restriction. Quotting from the > > commit ID: > > IIRC, the current behavior allows the process to be placed into a cgroup > with a subset of CPUs and you just can do 'cyclictest -a -t'. Process > should not ignore external configuration. That's my whole point here. In that case again I think a sane solution is not to check the cpu list in every single tool we use, because even if we do that for all tools in rt-teets repo, we can't guarantee to have this check for the rest tools to not ignore this restriction. A simple example is: what if the user specified "taskset -c $CPU cyclictest -a $CPU -t 1 ..." where $CPU is not in the allowed list of current bash? As long as the taskset would work the so-called "environment" will be changed before even loading cyclictest. If you see that's the point I said we should fail at the same check point of sched_setaffinity() rather than checking it explicitly in the tool, because if we want a real-world restriction that's the only place I think it's possible.. But I'm not a cgroup/container guy, please correct me if I understood. -- Peter Xu
