On 13/11/24 11:50, Waiman Long wrote: > > On 11/13/24 11:42 AM, Waiman Long wrote: > > > > On 11/13/24 11:40 AM, Juri Lelli wrote: > > > On 13/11/24 11:06, Waiman Long wrote: > > > > > > ... > > > > > > > This part can still cause a failure in one of test cases in my cpuset > > > > partition test script. In this particular case, the CPU to be > > > > offlined is an > > > > isolated CPU with scheduling disabled. As a result, total_bw is > > > > 0 and the > > > > __dl_overflow() test failed. Is there a way to skip the > > > > __dl_overflow() test > > > > for isolated CPUs? Can we use a null total_bw as a proxy for that? > > > Can you please share the repro script? Would like to check locally what > > > is going on. > > > > Just run tools/testing/selftests/cgroup/test_cpuset_prs.sh. > > The failing test is > > # Remote partition offline tests > " C0-3:S+ C1-3:S+ C2-3 . X2-3 X2-3 X2-3:P2:O2=0 . 0 > A1:0-1,A2:1,A3:3 A1:P0,A3:P2 2-3" > > You can remove all the previous lines in the TEST_MATRIX to get to failed > test case immediately eliminating unnecessary noise in your testing. So, IIUC this test is doing the following # echo +cpuset >cgroup/cgroup.subtree_control # mkdir cgroup/A1 # echo 0-3 >cgroup/A1/cpuset.cpus # echo +cpuset >cgroup/A1/cgroup.subtree_control # mkdir cgroup/A1/A2 # echo 1-3 >cgroup/A1/A2/cpuset.cpus # echo +cpuset >cgroup/A1/A2/cgroup.subtree_control # mkdir cgroup/A1/A2/A3 # echo 2-3 >cgroup/A1/A2/A3/cpuset.cpus # echo 2-3 >cgroup/A1/cpuset.cpus.exclusive # echo 2-3 >cgroup/A1/A2/cpuset.cpus.exclusive # echo 2-3 >cgroup/A1/A2/A3/cpuset.cpus.exclusive # echo isolated >cgroup/A1/A2/A3/cpuset.cpus.partition With the last command, we get to one root domain with span: 0-1,4-7 (in my setup with 8 CPUs) and no root domain for 2,3, since they are isolated. The test then tries to hotplug CPU 2, but fails to do so and so the reported error. total_bw for CPU 2 and CPU 3 is indeed 0, and I guess we could special case this as you suggest (nothing to really worry about if we don't have DEADLINE tasks affined to these CPUs). But I would have expected the fair server contribution to still show up in total_bw, so this is something a need to check. Thanks, Juri
