From 8e4645226b4931e96d55546a1fb3863aa50b5e62 Mon Sep 17 00:00:00 2001 From: Haifeng Xu Date: Tue, 28 Feb 2023 08:35:37 +0000 Subject: cpuset: Clean up cpuset_node_allowed Commit 002f290627c2 ("cpuset: use static key better and convert to new API") has used __cpuset_node_allowed() instead of cpuset_node_allowed() to check whether we can allocate on a memory node. Now this function isn't used by anyone, so we can do the follow things to clean up it. 1. remove unused codes 2. rename __cpuset_node_allowed() to cpuset_node_allowed() 3. update comments in mm/page_alloc.c Suggested-by: Waiman Long Signed-off-by: Haifeng Xu Acked-by: Waiman Long Signed-off-by: Tejun Heo --- kernel/cgroup/cpuset.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/cgroup/cpuset.c') diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 636f1c682ac0..0241b07d6f21 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3831,7 +3831,7 @@ static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs) } /* - * __cpuset_node_allowed - Can we allocate on a memory node? + * cpuset_node_allowed - Can we allocate on a memory node? * @node: is this an allowed node? * @gfp_mask: memory allocation flags * @@ -3870,7 +3870,7 @@ 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. */ -bool __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 */ bool allowed; /* is allocation in zone z allowed? */ -- cgit From df59b72cd8fb8ca00301f47e65853efed195d23f Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Fri, 17 Mar 2023 11:15:06 -0400 Subject: cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a hotplug event doesn't affect the current cpuset, there is no point to call hotplug_update_tasks() or hotplug_update_tasks_legacy(). So just skip it. Signed-off-by: Waiman Long Reviewed-by: Michal Koutný Signed-off-by: Tejun Heo --- kernel/cgroup/cpuset.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/cgroup/cpuset.c') diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 8472c711eb1b..a05bc93215ac 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3516,6 +3516,8 @@ retry: update_tasks: cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus); mems_updated = !nodes_equal(new_mems, cs->effective_mems); + if (!cpus_updated && !mems_updated) + goto unlock; /* Hotplug doesn't affect this cpuset */ if (mems_updated) check_insane_mems_config(&new_mems); @@ -3527,6 +3529,7 @@ update_tasks: hotplug_update_tasks_legacy(cs, &new_cpus, &new_mems, cpus_updated, mems_updated); +unlock: percpu_up_write(&cpuset_rwsem); } -- cgit From 6667439f51c446fead5d991ff49b842a811a6195 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Fri, 17 Mar 2023 11:15:07 -0400 Subject: cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated Similar to commit 3fb906e7fabb ("group/cpuset: Don't filter offline CPUs in cpuset_cpus_allowed() for top cpuset tasks"), the whole set of possible CPUs including offline ones should be used for setting cpumasks for tasks in the top cpuset when a cpuset partition is modified as the hotplug code won't update cpumasks for tasks in the top cpuset when CPUs become online or offline. Signed-off-by: Waiman Long Signed-off-by: Tejun Heo --- kernel/cgroup/cpuset.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'kernel/cgroup/cpuset.c') diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index a05bc93215ac..bc4dcfd7bee5 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1209,7 +1209,9 @@ void rebuild_sched_domains(void) * * Iterate through each task of @cs updating its cpus_allowed to the * effective cpuset's. As this function is called with cpuset_rwsem held, - * cpuset membership stays stable. + * cpuset membership stays stable. For top_cpuset, task_cpu_possible_mask() + * is used instead of effective_cpus to make sure all offline CPUs are also + * included as hotplug code won't update cpumasks for tasks in top_cpuset. */ static void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus) { @@ -1219,15 +1221,18 @@ static void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus) css_task_iter_start(&cs->css, 0, &it); while ((task = css_task_iter_next(&it))) { - /* - * Percpu kthreads in top_cpuset are ignored - */ - if (top_cs && (task->flags & PF_KTHREAD) && - kthread_is_per_cpu(task)) - continue; + const struct cpumask *possible_mask = task_cpu_possible_mask(task); - cpumask_and(new_cpus, cs->effective_cpus, - task_cpu_possible_mask(task)); + if (top_cs) { + /* + * Percpu kthreads in top_cpuset are ignored + */ + if ((task->flags & PF_KTHREAD) && kthread_is_per_cpu(task)) + continue; + cpumask_andnot(new_cpus, possible_mask, cs->subparts_cpus); + } else { + cpumask_and(new_cpus, possible_mask, cs->effective_cpus); + } set_cpus_allowed_ptr(task, new_cpus); } css_task_iter_end(&it); -- cgit