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authorTejun Heo <tj@kernel.org>2015-01-06 18:26:10 +0300
committerTejun Heo <tj@kernel.org>2015-01-06 18:26:10 +0300
commit4c907baf36d8339f393bb576d0bab29194d0e6ad (patch)
tree86a550f40df9f004913f5b6db4b1e3b69e7d040e /include/linux/percpu-refcount.h
parent6810e4a394f9d781050107529b8d1465c00b7b13 (diff)
downloadlinux-4c907baf36d8339f393bb576d0bab29194d0e6ad.tar.xz
percpu_ref: implement percpu_ref_is_dying()
Implement percpu_ref_is_dying() which tests whether the ref is dying or dead. This is useful to determine the current state when a percpu_ref is used as a cyclic on/off switch via kill and reinit. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kent Overstreet <kmo@daterainc.com>
Diffstat (limited to 'include/linux/percpu-refcount.h')
-rw-r--r--include/linux/percpu-refcount.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 6a7a670366ab..12c9b485beb7 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -295,6 +295,20 @@ static inline void percpu_ref_put(struct percpu_ref *ref)
}
/**
+ * percpu_ref_is_dying - test whether a percpu refcount is dying or dead
+ * @ref: percpu_ref to test
+ *
+ * Returns %true if @ref is dying or dead.
+ *
+ * This function is safe to call as long as @ref is between init and exit
+ * and the caller is responsible for synchronizing against state changes.
+ */
+static inline bool percpu_ref_is_dying(struct percpu_ref *ref)
+{
+ return ref->percpu_count_ptr & __PERCPU_REF_DEAD;
+}
+
+/**
* percpu_ref_is_zero - test whether a percpu refcount reached zero
* @ref: percpu_ref to test
*