Hello! v2 of a patch series [3] that addresses two issues affecting DEADLINE bandwidth accounting during non-destructive changes to root domains and hotplug operations. The series is based on top of Waiman's "cgroup/cpuset: Remove redundant rebuild_sched_domains_locked() calls" series [1] which is now merged into cgroups/for-6.13 (this series is based on top of that, commit c4c9cebe2fb9). The discussion that eventually led to these two series can be found at [2]. Waiman reported that v1 still failed to make his test_cpuset_prs.sh happy, so I had to change both patches a little. It now seems to pass on my runs. Patch 01/02 deals with non-destructive root domain changes. With respect to v1 we now always restore dl_server contributions, considering root domain span and active cpus mask (otherwise accounting on the default root domain would end up to be incorrect). Patch 02/02 deals with hotplug. With respect to v1 I added special casing when total_bw = 0 (so no DEADLINE tasks to consider) and when a root domain is left with no cpus due to hotplug. In all honesty, I still see intermittent issues that seems to however be related to the dance we do in sched_cpu_deactivate(), where we first turn everything related to a cpu/rq off and revert that if cpuset_cpu_inactive() reveals failing DEADLINE checks. But, since these seem to be orthogonal to the original discussion we started from, I wanted to send this out as an hopefully meaningful update/improvement since yesterday. Will continue looking into this. Please go forth and test/review. Series also available at git@xxxxxxxxxx:jlelli/linux.git upstream/dl-server-apply Best, Juri [1] https://lore.kernel.org/lkml/20241110025023.664487-1-longman@xxxxxxxxxx/ [2] https://lore.kernel.org/lkml/20241029225116.3998487-1-joel@xxxxxxxxxxxxxxxxx/ [3] v1 - https://lore.kernel.org/lkml/20241113125724.450249-1-juri.lelli@xxxxxxxxxx/ Juri Lelli (2): sched/deadline: Restore dl_server bandwidth on non-destructive root domain changes sched/deadline: Correctly account for allocated bandwidth during hotplug kernel/sched/core.c | 2 +- kernel/sched/deadline.c | 65 +++++++++++++++++++++++++++++++++-------- kernel/sched/sched.h | 2 +- kernel/sched/topology.c | 8 +++-- 4 files changed, 60 insertions(+), 17 deletions(-) -- 2.47.0
