cgroup/cpuset: Eliminate unncessary sched domains rebuilds in hotplug
It was found that some hotplug operations may cause multiple rebuild_sched_domains_locked() calls. Some of those intermediate calls may use cpuset states not in the final correct form leading to incorrect sched domain setting. Fix this problem by using the existing force_rebuild flag to inhibit immediate rebuild_sched_domains_locked() calls if set and only doing one final call at the end. Also renaming the force_rebuild flag to force_sd_rebuild to make its meaning for clear. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
parent
311a1bdc44
commit
ff0ce721ec
@ -232,6 +232,13 @@ static cpumask_var_t isolated_cpus;
|
||||
/* List of remote partition root children */
|
||||
static struct list_head remote_children;
|
||||
|
||||
/*
|
||||
* A flag to force sched domain rebuild at the end of an operation while
|
||||
* inhibiting it in the intermediate stages when set. Currently it is only
|
||||
* set in hotplug code.
|
||||
*/
|
||||
static bool force_sd_rebuild;
|
||||
|
||||
/*
|
||||
* Partition root states:
|
||||
*
|
||||
@ -1475,7 +1482,7 @@ static void update_partition_sd_lb(struct cpuset *cs, int old_prs)
|
||||
clear_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
|
||||
}
|
||||
|
||||
if (rebuild_domains)
|
||||
if (rebuild_domains && !force_sd_rebuild)
|
||||
rebuild_sched_domains_locked();
|
||||
}
|
||||
|
||||
@ -1833,7 +1840,7 @@ static void remote_partition_check(struct cpuset *cs, struct cpumask *newmask,
|
||||
remote_partition_disable(child, tmp);
|
||||
disable_cnt++;
|
||||
}
|
||||
if (disable_cnt)
|
||||
if (disable_cnt && !force_sd_rebuild)
|
||||
rebuild_sched_domains_locked();
|
||||
}
|
||||
|
||||
@ -2442,7 +2449,8 @@ get_css:
|
||||
}
|
||||
rcu_read_unlock();
|
||||
|
||||
if (need_rebuild_sched_domains && !(flags & HIER_NO_SD_REBUILD))
|
||||
if (need_rebuild_sched_domains && !(flags & HIER_NO_SD_REBUILD) &&
|
||||
!force_sd_rebuild)
|
||||
rebuild_sched_domains_locked();
|
||||
}
|
||||
|
||||
@ -3104,7 +3112,8 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
|
||||
cs->flags = trialcs->flags;
|
||||
spin_unlock_irq(&callback_lock);
|
||||
|
||||
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
|
||||
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed &&
|
||||
!force_sd_rebuild)
|
||||
rebuild_sched_domains_locked();
|
||||
|
||||
if (spread_flag_changed)
|
||||
@ -4501,11 +4510,9 @@ hotplug_update_tasks(struct cpuset *cs,
|
||||
update_tasks_nodemask(cs);
|
||||
}
|
||||
|
||||
static bool force_rebuild;
|
||||
|
||||
void cpuset_force_rebuild(void)
|
||||
{
|
||||
force_rebuild = true;
|
||||
force_sd_rebuild = true;
|
||||
}
|
||||
|
||||
/**
|
||||
@ -4653,15 +4660,9 @@ static void cpuset_handle_hotplug(void)
|
||||
!cpumask_empty(subpartitions_cpus);
|
||||
mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems);
|
||||
|
||||
/*
|
||||
* In the rare case that hotplug removes all the cpus in
|
||||
* subpartitions_cpus, we assumed that cpus are updated.
|
||||
*/
|
||||
if (!cpus_updated && !cpumask_empty(subpartitions_cpus))
|
||||
cpus_updated = true;
|
||||
|
||||
/* For v1, synchronize cpus_allowed to cpu_active_mask */
|
||||
if (cpus_updated) {
|
||||
cpuset_force_rebuild();
|
||||
spin_lock_irq(&callback_lock);
|
||||
if (!on_dfl)
|
||||
cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
|
||||
@ -4717,8 +4718,8 @@ static void cpuset_handle_hotplug(void)
|
||||
}
|
||||
|
||||
/* rebuild sched domains if cpus_allowed has changed */
|
||||
if (cpus_updated || force_rebuild) {
|
||||
force_rebuild = false;
|
||||
if (force_sd_rebuild) {
|
||||
force_sd_rebuild = false;
|
||||
rebuild_sched_domains_cpuslocked();
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user