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cpuset: Make nr_cpusets private

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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>
This commit is contained in:
Paolo Bonzini
2017-08-01 17:24:06 +02:00
committed by Ingo Molnar
parent 7a34bcb8b2
commit be040bea90
2 changed files with 7 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/cpuset.h
View File

@@ -37,12 +37,6 @@ static inline bool cpusets_enabled(void)
return static_branch_unlikely(&cpusets_enabled_key); 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 inline void cpuset_inc(void)
{ {
static_branch_inc(&cpusets_pre_enable_key); static_branch_inc(&cpusets_pre_enable_key);

7
kernel/cgroup/cpuset.c
View File

@@ -577,6 +577,13 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
rcu_read_unlock(); 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() * generate_sched_domains()
* *