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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 12:15:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 12:15:00 -0700
commit00bcf5cdd6c0e2e92ce3dd852ca68a3b779fa4ec (patch)
tree387b2ed2ac0e35776714515665f25ddb5fee1de3 /kernel/rcu
parentde956b8f45b3338cfb66a725e22b4050109daf2a (diff)
parent08645077b7f9f7824dbaf1959b0e014a894c8acc (diff)
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Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - rwsem micro-optimizations (Davidlohr Bueso) - Improve the implementation and optimize the performance of percpu-rwsems. (Peter Zijlstra.) - Convert all lglock users to better facilities such as percpu-rwsems or percpu-spinlocks and remove lglocks. (Peter Zijlstra) - Remove the ticket (spin)lock implementation. (Peter Zijlstra) - Korean translation of memory-barriers.txt and related fixes to the English document. (SeongJae Park) - misc fixes and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/cmpxchg, locking/atomics: Remove superfluous definitions x86, locking/spinlocks: Remove ticket (spin)lock implementation locking/lglock: Remove lglock implementation stop_machine: Remove stop_cpus_lock and lg_double_lock/unlock() fs/locks: Use percpu_down_read_preempt_disable() locking/percpu-rwsem: Add down_read_preempt_disable() fs/locks: Replace lg_local with a per-cpu spinlock fs/locks: Replace lg_global with a percpu-rwsem locking/percpu-rwsem: Add DEFINE_STATIC_PERCPU_RWSEMand percpu_rwsem_assert_held() locking/pv-qspinlock: Use cmpxchg_release() in __pv_queued_spin_unlock() locking/rwsem, x86: Drop a bogus cc clobber futex: Add some more function commentry locking/hung_task: Show all locks locking/rwsem: Scan the wait_list for readers only once locking/rwsem: Remove a few useless comments locking/rwsem: Return void in __rwsem_mark_wake() locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write() locking/Documentation: Add Korean translation locking/Documentation: Fix a typo of example result locking/Documentation: Fix wrong section reference ...
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/sync.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c
index be922c9f3d37..50d1861f7759 100644
--- a/kernel/rcu/sync.c
+++ b/kernel/rcu/sync.c
@@ -68,6 +68,8 @@ void rcu_sync_lockdep_assert(struct rcu_sync *rsp)
RCU_LOCKDEP_WARN(!gp_ops[rsp->gp_type].held(),
"suspicious rcu_sync_is_idle() usage");
}
+
+EXPORT_SYMBOL_GPL(rcu_sync_lockdep_assert);
#endif
/**
@@ -83,6 +85,18 @@ void rcu_sync_init(struct rcu_sync *rsp, enum rcu_sync_type type)
}
/**
+ * Must be called after rcu_sync_init() and before first use.
+ *
+ * Ensures rcu_sync_is_idle() returns false and rcu_sync_{enter,exit}()
+ * pairs turn into NO-OPs.
+ */
+void rcu_sync_enter_start(struct rcu_sync *rsp)
+{
+ rsp->gp_count++;
+ rsp->gp_state = GP_PASSED;
+}
+
+/**
* rcu_sync_enter() - Force readers onto slowpath
* @rsp: Pointer to rcu_sync structure to use for synchronization
*