diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 63 |
1 files changed, 37 insertions, 26 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 1902956baba1..2b4c20ab5bbe 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -61,7 +61,7 @@ #include <linux/cgroup.h> #include <linux/wait.h> -struct static_key cpusets_enabled_key __read_mostly = STATIC_KEY_INIT_FALSE; +DEFINE_STATIC_KEY_FALSE(cpusets_enabled_key); /* See "Frequency meter" comments, below. */ @@ -325,8 +325,7 @@ 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. @@ -335,8 +334,20 @@ 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); } @@ -1034,15 +1045,6 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk, { bool need_loop; - /* - * Allow tasks that have access to memory reserves because they have - * been OOM killed to get memory anywhere. - */ - if (unlikely(test_thread_flag(TIF_MEMDIE))) - return; - if (current->flags & PF_EXITING) /* Let dying task have memory */ - return; - task_lock(tsk); /* * Determine if a loop is necessary if another thread is doing @@ -2078,6 +2080,20 @@ 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. + */ +static 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, @@ -2088,6 +2104,7 @@ struct cgroup_subsys cpuset_cgrp_subsys = { .attach = cpuset_attach, .post_attach = cpuset_post_attach, .bind = cpuset_bind, + .fork = cpuset_fork, .legacy_cftypes = files, .early_init = true, }; @@ -2528,27 +2545,27 @@ static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs) * GFP_KERNEL - any node in enclosing hardwalled cpuset ok * GFP_USER - only nodes in current tasks mems allowed ok. */ -int __cpuset_node_allowed(int node, gfp_t gfp_mask) +bool __cpuset_node_allowed(int node, gfp_t gfp_mask) { struct cpuset *cs; /* current cpuset ancestors */ int allowed; /* is allocation in zone z allowed? */ unsigned long flags; if (in_interrupt()) - return 1; + return true; if (node_isset(node, current->mems_allowed)) - return 1; + return true; /* * Allow tasks that have access to memory reserves because they have * been OOM killed to get memory anywhere. */ if (unlikely(test_thread_flag(TIF_MEMDIE))) - return 1; + return true; if (gfp_mask & __GFP_HARDWALL) /* If hardwall request, stop here */ - return 0; + return false; if (current->flags & PF_EXITING) /* Let dying task have memory */ - return 1; + return true; /* Not hardwall and node outside mems_allowed: scan up cpusets */ spin_lock_irqsave(&callback_lock, flags); @@ -2591,13 +2608,7 @@ int __cpuset_node_allowed(int node, gfp_t gfp_mask) static int cpuset_spread_node(int *rotor) { - int node; - - node = next_node(*rotor, current->mems_allowed); - if (node == MAX_NUMNODES) - node = first_node(current->mems_allowed); - *rotor = node; - return node; + return *rotor = next_node_in(*rotor, current->mems_allowed); } int cpuset_mem_spread_node(void) |