Commit 3bfe4796 authored by Waiman Long's avatar Waiman Long Committed by Tejun Heo
Browse files

cgroup/cpuset: Move housekeeping_update()/rebuild_sched_domains() together 



With the latest changes in sched/isolation.c, rebuild_sched_domains*()
requires the HK_TYPE_DOMAIN housekeeping cpumask to be properly
updated first, if needed, before the sched domains can be
rebuilt. So the two naturally fit together. Do that by creating a new
update_hk_sched_domains() helper to house both actions.

The name of the isolated_cpus_updating flag to control the
call to housekeeping_update() is now outdated. So change it to
update_housekeeping to better reflect its purpose. Also move the call
to update_hk_sched_domains() to the end of cpuset and hotplug operations
before releasing the cpuset_mutex.

Signed-off-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 5e6aac57

kernel/cgroup/cpuset.c

+24 −27
Original line number Diff line number Diff line
@@ -130,10 +130,9 @@ static cpumask_var_t subpartitions_cpus; /* RWCS */ 
static cpumask_var_t	isolated_cpus;		/* CSCB */



/*

 * Set if isolated_cpus is being updated in the current cpuset_mutex

 * critical section.

 * Set if housekeeping cpumasks are to be updated.

 */

static bool		isolated_cpus_updating;	/* RWCS */

static bool		update_housekeeping;	/* RWCS */



/*

 * A flag to force sched domain rebuild at the end of an operation.
@@ -1189,7 +1188,7 @@ static void isolated_cpus_update(int old_prs, int new_prs, struct cpumask *xcpus 
			return;

		cpumask_andnot(isolated_cpus, isolated_cpus, xcpus);

	}

	isolated_cpus_updating = true;

	update_housekeeping = true;

}



/*
@@ -1307,22 +1306,22 @@ static bool prstate_housekeeping_conflict(int prstate, struct cpumask *new_cpus) 
}



/*

 * update_isolation_cpumasks - Update external isolation related CPU masks

 * update_hk_sched_domains - Update HK cpumasks & rebuild sched domains

 *

 * The following external CPU masks will be updated if necessary:

 * - workqueue unbound cpumask

 * Update housekeeping cpumasks and rebuild sched domains if necessary.

 * This should be called at the end of cpuset or hotplug actions.

 */

static void update_isolation_cpumasks(void)

static void update_hk_sched_domains(void)

{

	int ret;



	if (!isolated_cpus_updating)

		return;



	ret = housekeeping_update(isolated_cpus);

	WARN_ON_ONCE(ret < 0);



	isolated_cpus_updating = false;

	if (update_housekeeping) {

		/* Updating HK cpumasks implies rebuild sched domains */

		WARN_ON_ONCE(housekeeping_update(isolated_cpus));

		update_housekeeping = false;

		force_sd_rebuild = true;

	}

	/* force_sd_rebuild will be cleared in rebuild_sched_domains_locked() */

	if (force_sd_rebuild)

		rebuild_sched_domains_locked();

}



/**
@@ -1473,7 +1472,6 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs, 
	cs->remote_partition = true;

	cpumask_copy(cs->effective_xcpus, tmp->new_cpus);

	spin_unlock_irq(&callback_lock);

	update_isolation_cpumasks();

	cpuset_force_rebuild();

	cs->prs_err = 0;
@@ -1518,7 +1516,6 @@ static void remote_partition_disable(struct cpuset *cs, struct tmpmasks *tmp) 
	compute_excpus(cs, cs->effective_xcpus);

	reset_partition_data(cs);

	spin_unlock_irq(&callback_lock);

	update_isolation_cpumasks();

	cpuset_force_rebuild();



	/*
@@ -1589,7 +1586,6 @@ static void remote_cpus_update(struct cpuset *cs, struct cpumask *xcpus, 
	if (xcpus)

		cpumask_copy(cs->exclusive_cpus, xcpus);

	spin_unlock_irq(&callback_lock);

	update_isolation_cpumasks();

	if (adding || deleting)

		cpuset_force_rebuild();
@@ -1933,7 +1929,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, 
		partition_xcpus_add(new_prs, parent, tmp->delmask);



	spin_unlock_irq(&callback_lock);

	update_isolation_cpumasks();



	if ((old_prs != new_prs) && (cmd == partcmd_update))

		update_partition_exclusive_flag(cs, new_prs);
@@ -2901,7 +2896,6 @@ static int update_prstate(struct cpuset *cs, int new_prs) 
	else if (isolcpus_updated)

		isolated_cpus_update(old_prs, new_prs, cs->effective_xcpus);

	spin_unlock_irq(&callback_lock);

	update_isolation_cpumasks();



	/* Force update if switching back to member & update effective_xcpus */

	update_cpumasks_hier(cs, &tmpmask, !new_prs);
@@ -3191,9 +3185,8 @@ ssize_t cpuset_write_resmask(struct kernfs_open_file *of, 
	}



	free_cpuset(trialcs);

	if (force_sd_rebuild)

		rebuild_sched_domains_locked();

out_unlock:

	update_hk_sched_domains();

	cpuset_full_unlock();

	if (of_cft(of)->private == FILE_MEMLIST)

		schedule_flush_migrate_mm();
@@ -3301,6 +3294,7 @@ static ssize_t cpuset_partition_write(struct kernfs_open_file *of, char *buf, 
	cpuset_full_lock();

	if (is_cpuset_online(cs))

		retval = update_prstate(cs, val);

	update_hk_sched_domains();

	cpuset_full_unlock();

	return retval ?: nbytes;

}
@@ -3475,6 +3469,7 @@ static void cpuset_css_killed(struct cgroup_subsys_state *css) 
	/* Reset valid partition back to member */

	if (is_partition_valid(cs))

		update_prstate(cs, PRS_MEMBER);

	update_hk_sched_domains();

	cpuset_full_unlock();

}
@@ -3882,10 +3877,12 @@ static void cpuset_handle_hotplug(void) 
		rcu_read_unlock();

	}



	/* rebuild sched domains if necessary */

	if (force_sd_rebuild)

		rebuild_sched_domains_cpuslocked();



	if (update_housekeeping || force_sd_rebuild) {

		mutex_lock(&cpuset_mutex);

		update_hk_sched_domains();

		mutex_unlock(&cpuset_mutex);

	}

	free_tmpmasks(ptmp);

}