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authorPaolo Bonzini <pbonzini@redhat.com>2017-08-01 18:24:06 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:28:57 +0300
commitbe040bea9085a9c2b1700c9e60888777baeb96d5 (patch)
tree553fd82239ca9da9878bfef881e3d49d16dbcc06
parent7a34bcb8b272b1300f0125c93a54f0c98812acdd (diff)
downloadlinux-be040bea9085a9c2b1700c9e60888777baeb96d5.tar.xz
cpuset: Make nr_cpusets private
Any use of key->enabled (that is static_key_enabled and static_key_count) outside jump_label_lock should handle its own serialization. In the case of cpusets_enabled_key, the key is always incremented/decremented under cpuset_mutex, and hence the same rule applies to nr_cpusets. The rule *is* respected currently, but the mutex is static so nr_cpusets should be static too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Zefan Li <lizefan@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1501601046-35683-4-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/cpuset.h6
-rw-r--r--kernel/cgroup/cpuset.c7
2 files changed, 7 insertions, 6 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 898cfe2eeb42..e74655d941b7 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -37,12 +37,6 @@ static inline bool cpusets_enabled(void)
return static_branch_unlikely(&cpusets_enabled_key);
}
-static inline int nr_cpusets(void)
-{
- /* jump label reference count + the top-level cpuset */
- return static_key_count(&cpusets_enabled_key.key) + 1;
-}
-
static inline void cpuset_inc(void)
{
static_branch_inc(&cpusets_pre_enable_key);
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 8d5151688504..9ed6a051a1b9 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -577,6 +577,13 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
rcu_read_unlock();
}
+/* Must be called with cpuset_mutex held. */
+static inline int nr_cpusets(void)
+{
+ /* jump label reference count + the top-level cpuset */
+ return static_key_count(&cpusets_enabled_key.key) + 1;
+}
+
/*
* generate_sched_domains()
*