From 1344ab9c2991b45bacfd2e26a8800a62663ae427 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 9 Jul 2014 16:47:16 +0800 Subject: [PATCH] cpuset: update cpuset->effective_{cpus,mems} at hotplug We're going to have separate user-configured masks and effective ones. Eventually configured masks can only be changed by writing cpuset.cpus and cpuset.mems, and they won't be restricted by parent cpuset. While effective masks reflect cpu/memory hotplug and hierachical restriction, and these are the real masks that apply to the tasks in the cpuset. We calculate effective mask this way: - top cpuset's effective_mask == online_mask, otherwise - cpuset's effective_mask == configured_mask & parent effective_mask, if the result is empty, it inherits parent effective mask. Those behavior changes are for default hierarchy only. For legacy hierarchy, effective_mask and configured_mask are the same, so we won't break old interfaces. To make cs->effective_{cpus,mems} to be effective masks, we need to - update the effective masks at hotplug - update the effective masks at config change - take on ancestor's mask when the effective mask is empty The first item is done here. This won't introduce behavior change. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- kernel/cpuset.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index ef0974c73b4b..94f651d2eee5 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2082,6 +2082,7 @@ retry: mutex_lock(&callback_mutex); cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); + cpumask_andnot(cs->effective_cpus, cs->effective_cpus, &off_cpus); mutex_unlock(&callback_mutex); /* @@ -2096,6 +2097,7 @@ retry: mutex_lock(&callback_mutex); nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); + nodes_andnot(cs->effective_mems, cs->effective_mems, off_mems); mutex_unlock(&callback_mutex); /* @@ -2159,6 +2161,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) if (cpus_updated) { mutex_lock(&callback_mutex); cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); + cpumask_copy(top_cpuset.effective_cpus, &new_cpus); mutex_unlock(&callback_mutex); /* we don't mess with cpumasks of tasks in top_cpuset */ } @@ -2167,6 +2170,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) if (mems_updated) { mutex_lock(&callback_mutex); top_cpuset.mems_allowed = new_mems; + top_cpuset.effective_mems = new_mems; mutex_unlock(&callback_mutex); update_tasks_nodemask(&top_cpuset); }