diff options
| author | Juri Lelli <juri.lelli@redhat.com> | 2025-03-13 18:10:21 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-03-17 11:23:42 +0100 |
| commit | 2ff899e3516437354204423ef0a94994717b8e6a (patch) | |
| tree | 1e9fc392a4f839351bf9575c84ff1ece95c41cdf /kernel/cgroup | |
| parent | 45007c6fb5860cf63556a9cadc87c8984927e23d (diff) | |
sched/deadline: Rebuild root domain accounting after every update
Rebuilding of root domains accounting information (total_bw) is
currently broken on some cases, e.g. suspend/resume on aarch64. Problem
is that the way we keep track of domain changes and try to add bandwidth
back is convoluted and fragile.
Fix it by simplify things by making sure bandwidth accounting is cleared
and completely restored after root domains changes (after root domains
are again stable).
To be sure we always call dl_rebuild_rd_accounting while holding
cpuset_mutex we also add cpuset_reset_sched_domains() wrapper.
Fixes: 53916d5fd3c0 ("sched/deadline: Check bandwidth overflow earlier for hotplug")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Co-developed-by: Waiman Long <llong@redhat.com>
Signed-off-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MRfeJKJUOyUSto@jlelli-thinkpadt14gen4.remote.csb
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cpuset.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index f87526edb2a4..1892dc8cd211 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -954,10 +954,12 @@ static void dl_update_tasks_root_domain(struct cpuset *cs) css_task_iter_end(&it); } -static void dl_rebuild_rd_accounting(void) +void dl_rebuild_rd_accounting(void) { struct cpuset *cs = NULL; struct cgroup_subsys_state *pos_css; + int cpu; + u64 cookie = ++dl_cookie; lockdep_assert_held(&cpuset_mutex); lockdep_assert_cpus_held(); @@ -965,11 +967,12 @@ static void dl_rebuild_rd_accounting(void) rcu_read_lock(); - /* - * Clear default root domain DL accounting, it will be computed again - * if a task belongs to it. - */ - dl_clear_root_domain(&def_root_domain); + for_each_possible_cpu(cpu) { + if (dl_bw_visited(cpu, cookie)) + continue; + + dl_clear_root_domain_cpu(cpu); + } cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) { @@ -996,7 +999,6 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[], { sched_domains_mutex_lock(); partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); - dl_rebuild_rd_accounting(); sched_domains_mutex_unlock(); } @@ -1083,6 +1085,13 @@ void rebuild_sched_domains(void) cpus_read_unlock(); } +void cpuset_reset_sched_domains(void) +{ + mutex_lock(&cpuset_mutex); + partition_sched_domains(1, NULL, NULL); + mutex_unlock(&cpuset_mutex); +} + /** * cpuset_update_tasks_cpumask - Update the cpumasks of tasks in the cpuset. * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed |