diff options
author | Stefan Agner <stefan@agner.ch> | 2017-03-14 13:59:28 -0700 |
---|---|---|
committer | Max Krummenacher <max.krummenacher@toradex.com> | 2017-03-15 18:35:51 +0100 |
commit | 39ac0033f2345ce7b5d8ca4439192407dacb2355 (patch) | |
tree | 51dc588baa63d31bc406388885f62c1cae068fa3 /kernel/cpuset.c | |
parent | 13f2767f31803754aa883f298737aff866f04628 (diff) | |
parent | d9e0350d2575a20ee7783427da9bd6b6107eb983 (diff) |
Merge tag 'v4.1.39' into toradex_vf_4.1-nexttoradex_vf_4.1
Linux 4.1.39
Diffstat (limited to 'kernel/cpuset.c')
-rw-r--r-- | kernel/cpuset.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index f0acff0f66c9..71403502411b 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -323,8 +323,7 @@ static struct file_system_type cpuset_fs_type = { /* * Return in pmask the portion of a cpusets's cpus_allowed that * are online. If none are online, walk up the cpuset hierarchy - * until we find one that does have some online cpus. The top - * cpuset always has some cpus online. + * until we find one that does have some online cpus. * * One way or another, we guarantee to return some non-empty subset * of cpu_online_mask. @@ -333,8 +332,20 @@ static struct file_system_type cpuset_fs_type = { */ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) { - while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) + while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) { cs = parent_cs(cs); + if (unlikely(!cs)) { + /* + * The top cpuset doesn't have any online cpu as a + * consequence of a race between cpuset_hotplug_work + * and cpu hotplug notifier. But we know the top + * cpuset's effective_cpus is on its way to to be + * identical to cpu_online_mask. + */ + cpumask_copy(pmask, cpu_online_mask); + return; + } + } cpumask_and(pmask, cs->effective_cpus, cpu_online_mask); } @@ -2042,6 +2053,20 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css) mutex_unlock(&cpuset_mutex); } +/* + * Make sure the new task conform to the current state of its parent, + * which could have been changed by cpuset just after it inherits the + * state from the parent and before it sits on the cgroup's task list. + */ +void cpuset_fork(struct task_struct *task) +{ + if (task_css_is_root(task, cpuset_cgrp_id)) + return; + + set_cpus_allowed_ptr(task, ¤t->cpus_allowed); + task->mems_allowed = current->mems_allowed; +} + struct cgroup_subsys cpuset_cgrp_subsys = { .css_alloc = cpuset_css_alloc, .css_online = cpuset_css_online, @@ -2051,6 +2076,7 @@ struct cgroup_subsys cpuset_cgrp_subsys = { .cancel_attach = cpuset_cancel_attach, .attach = cpuset_attach, .bind = cpuset_bind, + .fork = cpuset_fork, .legacy_cftypes = files, .early_init = 1, }; |