Commit d2bafcf2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup fixes from Tejun Heo:
 "Three patches addressing cpuset corner cases"

* tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Eliminate unncessary sched domains rebuilds in hotplug
  cgroup/cpuset: Clear effective_xcpus on cpus_allowed clearing only if cpus.exclusive not set
  cgroup/cpuset: fix panic caused by partcmd_update
parents cb2c84b3 ff0ce721

kernel/cgroup/cpuset.c

+21 −17
Original line number Diff line number Diff line
@@ -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();

}
@@ -1991,6 +1998,8 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, 
			part_error = PERR_CPUSEMPTY;

			goto write_error;

		}

		/* Check newmask again, whether cpus are available for parent/cs */

		nocpu |= tasks_nocpu_error(parent, cs, newmask);



		/*

		 * partcmd_update with newmask:
@@ -2440,7 +2449,8 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp, 
	}

	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();

}
@@ -2523,6 +2533,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, 
	 */

	if (!*buf) {

		cpumask_clear(trialcs->cpus_allowed);

		if (cpumask_empty(trialcs->exclusive_cpus))

			cpumask_clear(trialcs->effective_xcpus);

	} else {

		retval = cpulist_parse(buf, trialcs->cpus_allowed);
@@ -3101,7 +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)
@@ -4498,11 +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;

}



/**
@@ -4650,15 +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);
@@ -4714,8 +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();

	}