SPL_AC_TYPE_ATOMIC64_XCHG
SPL_AC_TYPE_UINTPTR_T
SPL_AC_2ARGS_REGISTER_SYSCTL
- SPL_AC_SET_SHRINKER
- SPL_AC_3ARGS_SHRINKER_CALLBACK
+ SPL_AC_SHRINKER_CALLBACK
SPL_AC_PATH_IN_NAMEIDATA
SPL_AC_TASK_CURR
SPL_AC_CTL_UNNUMBERED
])
])
-dnl #
-dnl # 2.6.23 API change
-dnl # Old set_shrinker API replaced with register_shrinker
-dnl #
-AC_DEFUN([SPL_AC_SET_SHRINKER], [
- AC_MSG_CHECKING([whether set_shrinker() available])
- SPL_LINUX_TRY_COMPILE([
- #include <linux/mm.h>
- ],[
- return set_shrinker(DEFAULT_SEEKS, NULL);
- ],[
- AC_MSG_RESULT([yes])
- AC_DEFINE(HAVE_SET_SHRINKER, 1,
- [set_shrinker() available])
- ],[
- AC_MSG_RESULT([no])
- ])
-])
-
-dnl #
-dnl # 2.6.35 API change,
-dnl # Add context to shrinker callback
-dnl #
-AC_DEFUN([SPL_AC_3ARGS_SHRINKER_CALLBACK],
- [AC_MSG_CHECKING([whether shrinker callback wants 3 args])
+AC_DEFUN([SPL_AC_SHRINKER_CALLBACK],[
tmp_flags="$EXTRA_KCFLAGS"
EXTRA_KCFLAGS="-Werror"
+ dnl #
+ dnl # 2.6.23 to 2.6.34 API change
+ dnl # ->shrink(int nr_to_scan, gfp_t gfp_mask)
+ dnl #
+ AC_MSG_CHECKING([whether old 2-argument shrinker exists])
SPL_LINUX_TRY_COMPILE([
#include <linux/mm.h>
- int shrinker_cb(struct shrinker *, int, unsigned int);
+ int shrinker_cb(int nr_to_scan, gfp_t gfp_mask);
],[
struct shrinker cache_shrinker = {
.shrink = shrinker_cb,
register_shrinker(&cache_shrinker);
],[
AC_MSG_RESULT(yes)
- AC_DEFINE(HAVE_3ARGS_SHRINKER_CALLBACK, 1,
- [shrinker callback wants 3 args])
+ AC_DEFINE(HAVE_2ARGS_OLD_SHRINKER_CALLBACK, 1,
+ [old shrinker callback wants 2 args])
],[
AC_MSG_RESULT(no)
+ dnl #
+ dnl # 2.6.35 - 2.6.39 API change
+ dnl # ->shrink(struct shrinker *,
+ dnl # int nr_to_scan, gfp_t gfp_mask)
+ dnl #
+ AC_MSG_CHECKING([whether old 3-argument shrinker exists])
+ SPL_LINUX_TRY_COMPILE([
+ #include <linux/mm.h>
+
+ int shrinker_cb(struct shrinker *, int nr_to_scan,
+ gfp_t gfp_mask);
+ ],[
+ struct shrinker cache_shrinker = {
+ .shrink = shrinker_cb,
+ .seeks = DEFAULT_SEEKS,
+ };
+ register_shrinker(&cache_shrinker);
+ ],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_3ARGS_SHRINKER_CALLBACK, 1,
+ [old shrinker callback wants 3 args])
+ ],[
+ AC_MSG_RESULT(no)
+ dnl #
+ dnl # 3.0 - 3.11 API change
+ dnl # ->shrink(struct shrinker *,
+ dnl # struct shrink_control *sc)
+ dnl #
+ AC_MSG_CHECKING(
+ [whether new 2-argument shrinker exists])
+ SPL_LINUX_TRY_COMPILE([
+ #include <linux/mm.h>
+
+ int shrinker_cb(struct shrinker *,
+ struct shrink_control *sc);
+ ],[
+ struct shrinker cache_shrinker = {
+ .shrink = shrinker_cb,
+ .seeks = DEFAULT_SEEKS,
+ };
+ register_shrinker(&cache_shrinker);
+ ],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_2ARGS_NEW_SHRINKER_CALLBACK, 1,
+ [new shrinker callback wants 2 args])
+ ],[
+ AC_MSG_RESULT(no)
+ dnl #
+ dnl # 3.12 API change,
+ dnl # ->shrink() is logically split in to
+ dnl # ->count_objects() and ->scan_objects()
+ dnl #
+ AC_MSG_CHECKING(
+ [whether ->count_objects callback exists])
+ SPL_LINUX_TRY_COMPILE([
+ #include <linux/mm.h>
+
+ unsigned long shrinker_cb(
+ struct shrinker *,
+ struct shrink_control *sc);
+ ],[
+ struct shrinker cache_shrinker = {
+ .count_objects = shrinker_cb,
+ .scan_objects = shrinker_cb,
+ .seeks = DEFAULT_SEEKS,
+ };
+ register_shrinker(&cache_shrinker);
+ ],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_SPLIT_SHRINKER_CALLBACK,
+ 1, [->count_objects exists])
+ ],[
+ AC_MSG_ERROR(error)
+ ])
+ ])
+ ])
])
EXTRA_KCFLAGS="$tmp_flags"
])
#endif /* HAVE_SHRINK_ICACHE_MEMORY */
/*
- * Linux 2.6. - 2.6. Shrinker API Compatibility.
+ * Due to frequent changes in the shrinker API the following
+ * compatibility wrappers should be used. They are as follows:
+ *
+ * SPL_SHRINKER_DECLARE is used to declare the shrinker which is
+ * passed to spl_register_shrinker()/spl_unregister_shrinker(). Use
+ * shrinker_name to set the shrinker variable name, shrinker_callback
+ * to set the callback function, and seek_cost to define the cost of
+ * reclaiming an object.
+ *
+ * SPL_SHRINKER_DECLARE(shrinker_name, shrinker_callback, seek_cost);
+ *
+ * SPL_SHRINKER_CALLBACK_FWD_DECLARE is used when a forward declaration
+ * of the shrinker callback function is required. Only the callback
+ * function needs to be passed.
+ *
+ * SPL_SHRINKER_CALLBACK_FWD_DECLARE(shrinker_callback);
+ *
+ * SPL_SHRINKER_CALLBACK_WRAPPER is used to declare the callback function
+ * which is registered with the shrinker. This function will call your
+ * custom shrinker which must use the following prototype. Notice the
+ * leading __'s, these must be appended to the callback_function name.
+ *
+ * int __shrinker_callback(struct shrinker *, struct shrink_control *)
+ * SPL_SHRINKER_CALLBACK_WRAPPER(shrinker_callback);a
+ *
+ *
+ * Example:
+ *
+ * SPL_SHRINKER_CALLBACK_FWD_DECLARE(my_shrinker_fn);
+ * SPL_SHRINKER_DECLARE(my_shrinker, my_shrinker_fn, 1);
+ *
+ * static int
+ * __my_shrinker_fn(struct shrinker *shrink, struct shrink_control *sc)
+ * {
+ * if (sc->nr_to_scan) {
+ * ...scan objects in the cache and reclaim them...
+ * }
+ *
+ * ...calculate number of objects in the cache...
+ *
+ * return (number of objects in the cache);
+ * }
+ * SPL_SHRINKER_CALLBACK_WRAPPER(my_shrinker_fn);
*/
-#ifdef HAVE_SET_SHRINKER
-typedef struct spl_shrinker {
- struct shrinker *shrinker;
- shrinker_t fn;
- int seeks;
-} spl_shrinker_t;
-
-static inline void
-spl_register_shrinker(spl_shrinker_t *ss)
-{
- ss->shrinker = set_shrinker(ss->seeks, ss->fn);
-}
-static inline void
-spl_unregister_shrinker(spl_shrinker_t *ss)
-{
- remove_shrinker(ss->shrinker);
-}
+#define spl_register_shrinker(x) register_shrinker(x)
+#define spl_unregister_shrinker(x) unregister_shrinker(x)
-# define SPL_SHRINKER_DECLARE(s, x, y) \
- static spl_shrinker_t s = { \
- .shrinker = NULL, \
- .fn = x, \
- .seeks = y \
- }
-
-# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
- static int fn(int, unsigned int)
-# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
-static int \
-fn(int nr_to_scan, unsigned int gfp_mask) \
-{ \
- struct shrink_control sc; \
- \
- sc.nr_to_scan = nr_to_scan; \
- sc.gfp_mask = gfp_mask; \
- \
- return __ ## fn(NULL, &sc); \
+/*
+ * Linux 2.6.23 - 2.6.34 Shrinker API Compatibility.
+ */
+#if defined(HAVE_2ARGS_OLD_SHRINKER_CALLBACK)
+#define SPL_SHRINKER_DECLARE(s, x, y) \
+static struct shrinker s = { \
+ .shrink = x, \
+ .seeks = y \
}
-#else
+#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
+static int fn(int nr_to_scan, unsigned int gfp_mask)
-# define spl_register_shrinker(x) register_shrinker(x)
-# define spl_unregister_shrinker(x) unregister_shrinker(x)
-# define SPL_SHRINKER_DECLARE(s, x, y) \
- static struct shrinker s = { \
- .shrink = x, \
- .seeks = y \
- }
+#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
+static int \
+fn(int nr_to_scan, unsigned int gfp_mask) \
+{ \
+ struct shrink_control sc; \
+ \
+ sc.nr_to_scan = nr_to_scan; \
+ sc.gfp_mask = gfp_mask; \
+ \
+ return (__ ## fn(NULL, &sc)); \
+}
/*
- * Linux 2.6. - 2.6. Shrinker API Compatibility.
+ * Linux 2.6.35 to 2.6.39 Shrinker API Compatibility.
*/
-# if defined(HAVE_SHRINK_CONTROL_STRUCT)
-# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
- static int fn(struct shrinker *, struct shrink_control *)
-# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
-static int \
-fn(struct shrinker *shrink, struct shrink_control *sc) { \
- return __ ## fn(shrink, sc); \
+#elif defined(HAVE_3ARGS_SHRINKER_CALLBACK)
+#define SPL_SHRINKER_DECLARE(s, x, y) \
+static struct shrinker s = { \
+ .shrink = x, \
+ .seeks = y \
+}
+
+#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
+static int fn(struct shrinker *, int, unsigned int)
+
+#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
+static int \
+fn(struct shrinker *shrink, int nr_to_scan, unsigned int gfp_mask) \
+{ \
+ struct shrink_control sc; \
+ \
+ sc.nr_to_scan = nr_to_scan; \
+ sc.gfp_mask = gfp_mask; \
+ \
+ return (__ ## fn(shrink, &sc)); \
}
/*
- * Linux 2.6. - 2.6. Shrinker API Compatibility.
+ * Linux 3.0 to 3.11 Shrinker API Compatibility.
*/
-# elif defined(HAVE_3ARGS_SHRINKER_CALLBACK)
-# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
- static int fn(struct shrinker *, int, unsigned int)
-# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
-static int \
-fn(struct shrinker *shrink, int nr_to_scan, unsigned int gfp_mask) \
-{ \
- struct shrink_control sc; \
- \
- sc.nr_to_scan = nr_to_scan; \
- sc.gfp_mask = gfp_mask; \
- \
- return __ ## fn(shrink, &sc); \
+#elif defined(HAVE_2ARGS_NEW_SHRINKER_CALLBACK)
+#define SPL_SHRINKER_DECLARE(s, x, y) \
+static struct shrinker s = { \
+ .shrink = x, \
+ .seeks = y \
+}
+
+#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
+static int fn(struct shrinker *, struct shrink_control *)
+
+#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
+static int \
+fn(struct shrinker *shrink, struct shrink_control *sc) \
+{ \
+ return (__ ## fn(shrink, sc)); \
}
/*
- * Linux 2.6. - 2.6. Shrinker API Compatibility.
+ * Linux 3.12 and later Shrinker API Compatibility.
*/
-# else
-# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
- static int fn(int, unsigned int)
-# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
-static int \
-fn(int nr_to_scan, unsigned int gfp_mask) \
-{ \
- struct shrink_control sc; \
- \
- sc.nr_to_scan = nr_to_scan; \
- sc.gfp_mask = gfp_mask; \
- \
- return __ ## fn(NULL, &sc); \
+#elif defined(HAVE_SPLIT_SHRINKER_CALLBACK)
+#define SPL_SHRINKER_DECLARE(s, x, y) \
+static struct shrinker s = { \
+ .count_objects = x ## _count_objects, \
+ .scan_objects = x ## _scan_objects, \
+ .seeks = y \
}
-# endif
-#endif /* HAVE_SET_SHRINKER */
+#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
+static unsigned long fn ## _count_objects(struct shrinker *, \
+ struct shrink_control *); \
+static unsigned long fn ## _scan_objects(struct shrinker *, \
+ struct shrink_control *)
+
+#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
+static unsigned long \
+fn ## _count_objects(struct shrinker *shrink, struct shrink_control *sc)\
+{ \
+ int __ret__; \
+ \
+ sc->nr_to_scan = 0; \
+ __ret__ = __ ## fn(NULL, sc); \
+ \
+ /* Errors may not be returned and must be converted to zeros */ \
+ return ((__ret__ < 0) ? 0 : __ret__); \
+} \
+ \
+static unsigned long \
+fn ## _scan_objects(struct shrinker *shrink, struct shrink_control *sc) \
+{ \
+ int __ret__; \
+ \
+ __ret__ = __ ## fn(NULL, sc); \
+ return ((__ret__ < 0) ? SHRINK_STOP : __ret__); \
+}
+#else
+/*
+ * Linux 2.x to 2.6.22, or a newer shrinker API has been introduced.
+ */
+#error "Unknown shrinker callback"
+#endif
#endif /* SPL_MM_COMPAT_H */
projects / zfs / commitdiff