The limitation that update_parent_subparts_cpumask() can only use addmask & delmask in the given tmp cpumasks is fragile and may lead to unexpected error.
Fix this problem by allocating/freeing a struct tmpmasks in update_cpumask() to avoid reusing the cpumasks in trial_cs.
With this change, we can move the update_tasks_cpumask() for the parent and update_sibling_cpumasks() for the sibling to inside update_parent_subparts_cpumask().
Signed-off-by: Waiman Long longman@redhat.com --- kernel/cgroup/cpuset.c | 42 +++++++++++++----------------------------- 1 file changed, 13 insertions(+), 29 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index ade33e50ffe2..b8ccc1be7bde 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1277,6 +1277,8 @@ enum subparts_cmd {
static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, int turning_on); +static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs, + struct tmpmasks *tmp);
/* * Update partition exclusive flag @@ -1447,7 +1449,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cs, int cmd, adding = cpumask_andnot(tmp->addmask, tmp->addmask, parent->subparts_cpus); /* - * Empty cpumask is not allewed + * Empty cpumask is not allowed */ if (cpumask_empty(newmask)) { part_error = PERR_CPUSEMPTY; @@ -1567,8 +1569,11 @@ static int update_parent_subparts_cpumask(struct cpuset *cs, int cmd,
spin_unlock_irq(&callback_lock);
- if (adding || deleting) + if (adding || deleting) { update_tasks_cpumask(parent, tmp->addmask); + if (parent->child_ecpus_count) + update_sibling_cpumasks(parent, cs, tmp); + }
/* * For partcmd_update without newmask, it is being called from @@ -1842,18 +1847,8 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed)) return 0;
-#ifdef CONFIG_CPUMASK_OFFSTACK - /* - * Use the cpumasks in trialcs for tmpmasks when they are pointers - * to allocated cpumasks. - * - * Note that update_parent_subparts_cpumask() uses only addmask & - * delmask, but not new_cpus. - */ - tmp.addmask = trialcs->subparts_cpus; - tmp.delmask = trialcs->effective_cpus; - tmp.new_cpus = NULL; -#endif + if (alloc_cpumasks(NULL, &tmp)) + return -ENOMEM;
retval = validate_change(cs, trialcs);
@@ -1882,7 +1877,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, retval = 0; } if (retval < 0) - return retval; + goto out_free;
if (cs->partition_root_state) { if (invalidate) @@ -1917,11 +1912,6 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, } spin_unlock_irq(&callback_lock);
-#ifdef CONFIG_CPUMASK_OFFSTACK - /* Now trialcs->cpus_allowed is available */ - tmp.new_cpus = trialcs->cpus_allowed; -#endif - /* effective_cpus will be updated here */ update_cpumasks_hier(cs, &tmp, false);
@@ -1938,6 +1928,8 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, /* Update CS_SCHED_LOAD_BALANCE and/or sched_domains */ update_partition_sd_lb(cs, old_prs); } +out_free: + free_cpumasks(NULL, &tmp); return 0; }
@@ -2346,13 +2338,11 @@ static int update_prstate(struct cpuset *cs, int new_prs)
err = update_parent_subparts_cpumask(cs, partcmd_enable, NULL, &tmpmask); - if (err) - goto out; } else if (old_prs && new_prs) { /* * A change in load balance state only, no change in cpumasks. */ - goto out; + ; } else { /* * Switching back to member is always allowed even if it @@ -2372,12 +2362,6 @@ static int update_prstate(struct cpuset *cs, int new_prs) spin_unlock_irq(&callback_lock); } } - - update_tasks_cpumask(parent, tmpmask.new_cpus); - - if (parent->child_ecpus_count) - update_sibling_cpumasks(parent, cs, &tmpmask); - out: /* * Make partition invalid & disable CS_CPU_EXCLUSIVE if an error