Commit be040bea authored Aug 01, 2017 by Paolo Bonzini Committed by Ingo Molnar Aug 10, 2017

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>

parent 7a34bcb8

include/linux/cpuset.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -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);

kernel/cgroup/cpuset.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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()
		*