projects/linux·commit 2f4f12e5

lockref: uninline lockref helper functions

2f4f12e5 · Linus Torvalds <[email protected]> · 2013-09-02 11:58:20 -07:00

They aren't very good to inline, since they already call external
functions (the spinlock code), and we're going to create rather more
complicated versions of them that can do the reference count updates
locklessly.

Signed-off-by: Linus Torvalds <[email protected]>
Commit
2f4f12e571c4e2f50f3818a3c2544929145f75dd
Parents
15570086

Changes

3 files changed · +74 −62

FileStatusAddDelContent
include/linux/lockref.hmodified+4−62View file
lib/Makefilemodified+1−0View file
lib/lockref.cadded+69−0View file

include/linux/lockref.h

View file
diff --git a/include/linux/lockref.h b/include/linux/lockref.h
index 0ea0260..4c0af31 100644
--- a/include/linux/lockref.h
+++ b/include/linux/lockref.h
@@ -21,67 +21,9 @@ struct lockref {
unsigned int count;
};
-/**
- * lockref_get - Increments reference count unconditionally
- * @lockcnt: pointer to lockref structure
- *
- * This operation is only valid if you already hold a reference
- * to the object, so you know the count cannot be zero.
- */
-static inline void lockref_get(struct lockref *lockref)
-{
- spin_lock(&lockref->lock);
- lockref->count++;
- spin_unlock(&lockref->lock);
-}
-
-/**
- * lockref_get_not_zero - Increments count unless the count is 0
- * @lockcnt: pointer to lockref structure
- * Return: 1 if count updated successfully or 0 if count is 0
- */
-static inline int lockref_get_not_zero(struct lockref *lockref)
-{
- int retval = 0;
-
- spin_lock(&lockref->lock);
- if (lockref->count) {
- lockref->count++;
- retval = 1;
- }
- spin_unlock(&lockref->lock);
- return retval;
-}
-
-/**
- * lockref_get_or_lock - Increments count unless the count is 0
- * @lockcnt: pointer to lockref structure
- * Return: 1 if count updated successfully or 0 if count was zero
- * and we got the lock instead.
- */
-static inline int lockref_get_or_lock(struct lockref *lockref)
-{
- spin_lock(&lockref->lock);
- if (!lockref->count)
- return 0;
- lockref->count++;
- spin_unlock(&lockref->lock);
- return 1;
-}
-
-/**
- * lockref_put_or_lock - decrements count unless count <= 1 before decrement
- * @lockcnt: pointer to lockref structure
- * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken
- */
-static inline int lockref_put_or_lock(struct lockref *lockref)
-{
- spin_lock(&lockref->lock);
- if (lockref->count <= 1)
- return 0;
- lockref->count--;
- spin_unlock(&lockref->lock);
- return 1;
-}
+extern void lockref_get(struct lockref *);
+extern int lockref_get_not_zero(struct lockref *);
+extern int lockref_get_or_lock(struct lockref *);
+extern int lockref_put_or_lock(struct lockref *);
#endif /* __LINUX_LOCKREF_H */

lib/Makefile

View file
diff --git a/lib/Makefile b/lib/Makefile
index 7baccfd..f2cb308 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -20,6 +20,7 @@ lib-$(CONFIG_MMU) += ioremap.o
lib-$(CONFIG_SMP) += cpumask.o
lib-y += kobject.o klist.o
+obj-y += lockref.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \

lib/lockref.c

View file
diff --git a/lib/lockref.c b/lib/lockref.c
new file mode 100644
index 0000000..a9a4f4e
--- /dev/null
+++ b/lib/lockref.c
@@ -0,0 +1,69 @@
+#include <linux/export.h>
+#include <linux/lockref.h>
+
+/**
+ * lockref_get - Increments reference count unconditionally
+ * @lockcnt: pointer to lockref structure
+ *
+ * This operation is only valid if you already hold a reference
+ * to the object, so you know the count cannot be zero.
+ */
+void lockref_get(struct lockref *lockref)
+{
+ spin_lock(&lockref->lock);
+ lockref->count++;
+ spin_unlock(&lockref->lock);
+}
+EXPORT_SYMBOL(lockref_get);
+
+/**
+ * lockref_get_not_zero - Increments count unless the count is 0
+ * @lockcnt: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count was zero
+ */
+int lockref_get_not_zero(struct lockref *lockref)
+{
+ int retval = 0;
+
+ spin_lock(&lockref->lock);
+ if (lockref->count) {
+ lockref->count++;
+ retval = 1;
+ }
+ spin_unlock(&lockref->lock);
+ return retval;
+}
+EXPORT_SYMBOL(lockref_get_not_zero);
+
+/**
+ * lockref_get_or_lock - Increments count unless the count is 0
+ * @lockcnt: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count was zero
+ * and we got the lock instead.
+ */
+int lockref_get_or_lock(struct lockref *lockref)
+{
+ spin_lock(&lockref->lock);
+ if (!lockref->count)
+ return 0;
+ lockref->count++;
+ spin_unlock(&lockref->lock);
+ return 1;
+}
+EXPORT_SYMBOL(lockref_get_or_lock);
+
+/**
+ * lockref_put_or_lock - decrements count unless count <= 1 before decrement
+ * @lockcnt: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken
+ */
+int lockref_put_or_lock(struct lockref *lockref)
+{
+ spin_lock(&lockref->lock);
+ if (lockref->count <= 1)
+ return 0;
+ lockref->count--;
+ spin_unlock(&lockref->lock);
+ return 1;
+}
+EXPORT_SYMBOL(lockref_put_or_lock);