From ae1c802382f7af60aa54879fb4f5920a9df1ff48 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 9 Jul 2014 16:48:32 +0800 Subject: cpuset: apply cs->effective_{cpus,mems} Now we can use cs->effective_{cpus,mems} as effective masks. It's used whenever: - we update tasks' cpus_allowed/mems_allowed, - we want to retrieve tasks_cs(tsk)'s cpus_allowed/mems_allowed. They actually replace effective_{cpu,node}mask_cpuset(). effective_mask == configured_mask & parent effective_mask except when the reault is empty, in which case it inherits parent effective_mask. The result equals the mask computed from effective_{cpu,node}mask_cpuset(). This won't affect the original legacy hierarchy, because in this case we make sure the effective masks are always the same with user-configured masks. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- kernel/cpuset.c | 83 ++++++++++----------------------------------------------- 1 file changed, 14 insertions(+), 69 deletions(-) (limited to 'kernel/cpuset.c') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index e4c31e6b8716..820870a715f8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -313,9 +313,9 @@ static struct file_system_type cpuset_fs_type = { */ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) { - while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask)) + while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) cs = parent_cs(cs); - cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask); + cpumask_and(pmask, cs->effective_cpus, cpu_online_mask); } /* @@ -331,9 +331,9 @@ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) */ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask) { - while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY])) + while (!nodes_intersects(cs->effective_mems, node_states[N_MEMORY])) cs = parent_cs(cs); - nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]); + nodes_and(*pmask, cs->effective_mems, node_states[N_MEMORY]); } /* @@ -795,45 +795,6 @@ void rebuild_sched_domains(void) mutex_unlock(&cpuset_mutex); } -/* - * effective_cpumask_cpuset - return nearest ancestor with non-empty cpus - * @cs: the cpuset in interest - * - * A cpuset's effective cpumask is the cpumask of the nearest ancestor - * with non-empty cpus. We use effective cpumask whenever: - * - we update tasks' cpus_allowed. (they take on the ancestor's cpumask - * if the cpuset they reside in has no cpus) - * - we want to retrieve task_cs(tsk)'s cpus_allowed. - * - * Called with cpuset_mutex held. cpuset_cpus_allowed_fallback() is an - * exception. See comments there. - */ -static struct cpuset *effective_cpumask_cpuset(struct cpuset *cs) -{ - while (cpumask_empty(cs->cpus_allowed)) - cs = parent_cs(cs); - return cs; -} - -/* - * effective_nodemask_cpuset - return nearest ancestor with non-empty mems - * @cs: the cpuset in interest - * - * A cpuset's effective nodemask is the nodemask of the nearest ancestor - * with non-empty memss. We use effective nodemask whenever: - * - we update tasks' mems_allowed. (they take on the ancestor's nodemask - * if the cpuset they reside in has no mems) - * - we want to retrieve task_cs(tsk)'s mems_allowed. - * - * Called with cpuset_mutex held. - */ -static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs) -{ - while (nodes_empty(cs->mems_allowed)) - cs = parent_cs(cs); - return cs; -} - /** * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset. * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed @@ -844,13 +805,12 @@ static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs) */ static void update_tasks_cpumask(struct cpuset *cs) { - struct cpuset *cpus_cs = effective_cpumask_cpuset(cs); struct css_task_iter it; struct task_struct *task; css_task_iter_start(&cs->css, &it); while ((task = css_task_iter_next(&it))) - set_cpus_allowed_ptr(task, cpus_cs->cpus_allowed); + set_cpus_allowed_ptr(task, cs->effective_cpus); css_task_iter_end(&it); } @@ -988,15 +948,13 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, const nodemask_t *to) { struct task_struct *tsk = current; - struct cpuset *mems_cs; tsk->mems_allowed = *to; do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL); rcu_read_lock(); - mems_cs = effective_nodemask_cpuset(task_cs(tsk)); - guarantee_online_mems(mems_cs, &tsk->mems_allowed); + guarantee_online_mems(task_cs(tsk), &tsk->mems_allowed); rcu_read_unlock(); } @@ -1065,13 +1023,12 @@ static void *cpuset_being_rebound; static void update_tasks_nodemask(struct cpuset *cs) { static nodemask_t newmems; /* protected by cpuset_mutex */ - struct cpuset *mems_cs = effective_nodemask_cpuset(cs); struct css_task_iter it; struct task_struct *task; cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ - guarantee_online_mems(mems_cs, &newmems); + guarantee_online_mems(cs, &newmems); /* * The mpol_rebind_mm() call takes mmap_sem, which we couldn't @@ -1497,8 +1454,6 @@ static void cpuset_attach(struct cgroup_subsys_state *css, struct task_struct *leader = cgroup_taskset_first(tset); struct cpuset *cs = css_cs(css); struct cpuset *oldcs = cpuset_attach_old_cs; - struct cpuset *cpus_cs = effective_cpumask_cpuset(cs); - struct cpuset *mems_cs = effective_nodemask_cpuset(cs); mutex_lock(&cpuset_mutex); @@ -1506,9 +1461,9 @@ static void cpuset_attach(struct cgroup_subsys_state *css, if (cs == &top_cpuset) cpumask_copy(cpus_attach, cpu_possible_mask); else - guarantee_online_cpus(cpus_cs, cpus_attach); + guarantee_online_cpus(cs, cpus_attach); - guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to); + guarantee_online_mems(cs, &cpuset_attach_nodemask_to); cgroup_taskset_for_each(task, tset) { /* @@ -1525,11 +1480,9 @@ static void cpuset_attach(struct cgroup_subsys_state *css, * Change mm, possibly for multiple threads in a threadgroup. This is * expensive and may sleep. */ - cpuset_attach_nodemask_to = cs->mems_allowed; + cpuset_attach_nodemask_to = cs->effective_mems; mm = get_task_mm(leader); if (mm) { - struct cpuset *mems_oldcs = effective_nodemask_cpuset(oldcs); - mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); /* @@ -1540,7 +1493,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css, * mm from. */ if (is_memory_migrate(cs)) { - cpuset_migrate_mm(mm, &mems_oldcs->old_mems_allowed, + cpuset_migrate_mm(mm, &oldcs->old_mems_allowed, &cpuset_attach_nodemask_to); } mmput(mm); @@ -2331,23 +2284,17 @@ void __init cpuset_init_smp(void) void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) { - struct cpuset *cpus_cs; - mutex_lock(&callback_mutex); rcu_read_lock(); - cpus_cs = effective_cpumask_cpuset(task_cs(tsk)); - guarantee_online_cpus(cpus_cs, pmask); + guarantee_online_cpus(task_cs(tsk), pmask); rcu_read_unlock(); mutex_unlock(&callback_mutex); } void cpuset_cpus_allowed_fallback(struct task_struct *tsk) { - struct cpuset *cpus_cs; - rcu_read_lock(); - cpus_cs = effective_cpumask_cpuset(task_cs(tsk)); - do_set_cpus_allowed(tsk, cpus_cs->cpus_allowed); + do_set_cpus_allowed(tsk, task_cs(tsk)->effective_cpus); rcu_read_unlock(); /* @@ -2386,13 +2333,11 @@ void cpuset_init_current_mems_allowed(void) nodemask_t cpuset_mems_allowed(struct task_struct *tsk) { - struct cpuset *mems_cs; nodemask_t mask; mutex_lock(&callback_mutex); rcu_read_lock(); - mems_cs = effective_nodemask_cpuset(task_cs(tsk)); - guarantee_online_mems(mems_cs, &mask); + guarantee_online_mems(task_cs(tsk), &mask); rcu_read_unlock(); mutex_unlock(&callback_mutex); -- cgit