six locks: Simplify dispatch

Originally, we used inlining/flattening to cause the compiler to
generate different versions of lock/trylock/relock/unlock for each lock
type - read, intent, and write. This made the individual functions
smaller and let the compiler eliminate table lookups: however, as the
code has gotten more complicated these optimizations have gotten less
worthwhile, and all the tricky inlining and dispatching made the code
less readable.

Text size: 11015 bytes -> 7467 bytes, and benchmarks show no loss of
performance.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/six.c b/fs/bcachefs/six.c
index d8f1d20f5ece5e71fb3100047a8e05ae29cbaaf4..1a64b8a027a7f7cf70621f9bd5cd98f5cd1791a1 100644 (file)
--- a/fs/bcachefs/six.c
+++ b/fs/bcachefs/six.c
@@ -245,9 +245,10 @@ unlock:
        }
 }
 
-static inline void six_lock_wakeup(struct six_lock *lock,
-                                  union six_lock_state state,
-                                  enum six_lock_type lock_type)
+__always_inline
+static void six_lock_wakeup(struct six_lock *lock,
+                           union six_lock_state state,
+                           enum six_lock_type lock_type)
 {
        if (lock_type == SIX_LOCK_write && state.read_lock)
                return;
@@ -258,6 +259,7 @@ static inline void six_lock_wakeup(struct six_lock *lock,
        __six_lock_wakeup(lock, lock_type);
 }
 
+__always_inline
 static bool do_six_trylock_type(struct six_lock *lock,
                                enum six_lock_type type,
                                bool try)
@@ -271,9 +273,8 @@ static bool do_six_trylock_type(struct six_lock *lock,
        return ret > 0;
 }
 
-__always_inline __flatten
-static bool __six_trylock_type(struct six_lock *lock, enum six_lock_type type,
-                              unsigned long ip)
+bool six_trylock_ip_type(struct six_lock *lock, enum six_lock_type type,
+                        unsigned long ip)
 {
        if (!do_six_trylock_type(lock, type, true))
                return false;
@@ -283,9 +284,8 @@ static bool __six_trylock_type(struct six_lock *lock, enum six_lock_type type,
        return true;
 }
 
-__always_inline __flatten
-static bool __six_relock_type(struct six_lock *lock, enum six_lock_type type,
-                             unsigned seq, unsigned long ip)
+bool six_relock_ip_type(struct six_lock *lock, enum six_lock_type type,
+                       unsigned seq, unsigned long ip)
 {
        const struct six_lock_vals l[] = LOCK_VALS;
        union six_lock_state old;
@@ -335,6 +335,7 @@ static bool __six_relock_type(struct six_lock *lock, enum six_lock_type type,
                six_acquire(&lock->dep_map, 1, type == SIX_LOCK_read, ip);
        return true;
 }
+EXPORT_SYMBOL_GPL(six_relock_ip_type);
 
 #ifdef CONFIG_SIX_LOCK_SPIN_ON_OWNER
 
@@ -566,11 +567,10 @@ out:
        return ret;
 }
 
-__always_inline __flatten
-static int __six_lock_type_waiter(struct six_lock *lock, enum six_lock_type type,
-                        struct six_lock_waiter *wait,
-                        six_lock_should_sleep_fn should_sleep_fn, void *p,
-                        unsigned long ip)
+int six_lock_type_ip_waiter(struct six_lock *lock, enum six_lock_type type,
+                           struct six_lock_waiter *wait,
+                           six_lock_should_sleep_fn should_sleep_fn, void *p,
+                           unsigned long ip)
 {
        int ret;
 
@@ -589,18 +589,9 @@ static int __six_lock_type_waiter(struct six_lock *lock, enum six_lock_type type
 
        return ret;
 }
+EXPORT_SYMBOL_GPL(six_lock_type_ip_waiter);
 
 __always_inline
-static int __six_lock_type(struct six_lock *lock, enum six_lock_type type,
-                          six_lock_should_sleep_fn should_sleep_fn, void *p,
-                          unsigned long ip)
-{
-       struct six_lock_waiter wait;
-
-       return __six_lock_type_waiter(lock, type, &wait, should_sleep_fn, p, ip);
-}
-
-__always_inline __flatten
 static void do_six_unlock_type(struct six_lock *lock, enum six_lock_type type)
 {
        const struct six_lock_vals l[] = LOCK_VALS;
@@ -628,9 +619,7 @@ static void do_six_unlock_type(struct six_lock *lock, enum six_lock_type type)
        six_lock_wakeup(lock, state, l[type].unlock_wakeup);
 }
 
-__always_inline __flatten
-static void __six_unlock_type(struct six_lock *lock, enum six_lock_type type,
-                             unsigned long ip)
+void six_unlock_ip_type(struct six_lock *lock, enum six_lock_type type, unsigned long ip)
 {
        EBUG_ON(type == SIX_LOCK_write &&
                !(lock->state.v & __SIX_LOCK_HELD_intent));
@@ -649,48 +638,7 @@ static void __six_unlock_type(struct six_lock *lock, enum six_lock_type type,
 
        do_six_unlock_type(lock, type);
 }
-
-#define __SIX_LOCK(type)                                               \
-bool six_trylock_ip_##type(struct six_lock *lock, unsigned long ip)    \
-{                                                                      \
-       return __six_trylock_type(lock, SIX_LOCK_##type, ip);           \
-}                                                                      \
-EXPORT_SYMBOL_GPL(six_trylock_ip_##type);                              \
-                                                                       \
-bool six_relock_ip_##type(struct six_lock *lock, u32 seq, unsigned long ip)\
-{                                                                      \
-       return __six_relock_type(lock, SIX_LOCK_##type, seq, ip);       \
-}                                                                      \
-EXPORT_SYMBOL_GPL(six_relock_ip_##type);                               \
-                                                                       \
-int six_lock_ip_##type(struct six_lock *lock,                          \
-                   six_lock_should_sleep_fn should_sleep_fn, void *p,  \
-                   unsigned long ip)                                   \
-{                                                                      \
-       return __six_lock_type(lock, SIX_LOCK_##type, should_sleep_fn, p, ip);\
-}                                                                      \
-EXPORT_SYMBOL_GPL(six_lock_ip_##type);                                 \
-                                                                       \
-int six_lock_ip_waiter_##type(struct six_lock *lock,                   \
-                          struct six_lock_waiter *wait,                \
-                          six_lock_should_sleep_fn should_sleep_fn, void *p,\
-                          unsigned long ip)                            \
-{                                                                      \
-       return __six_lock_type_waiter(lock, SIX_LOCK_##type, wait, should_sleep_fn, p, ip);\
-}                                                                      \
-EXPORT_SYMBOL_GPL(six_lock_ip_waiter_##type);                          \
-                                                                       \
-void six_unlock_ip_##type(struct six_lock *lock, unsigned long ip)     \
-{                                                                      \
-       __six_unlock_type(lock, SIX_LOCK_##type, ip);                   \
-}                                                                      \
-EXPORT_SYMBOL_GPL(six_unlock_ip_##type);
-
-__SIX_LOCK(read)
-__SIX_LOCK(intent)
-__SIX_LOCK(write)
-
-#undef __SIX_LOCK
+EXPORT_SYMBOL_GPL(six_unlock_ip_type);
 
 /* Convert from intent to read: */
 void six_lock_downgrade(struct six_lock *lock)

diff --git a/fs/bcachefs/six.h b/fs/bcachefs/six.h
index 2c8424bd7d2faf9571cb80f4613972cbccf413bf..5ddabbfb8aba41f3dc14de8e7c27613d31d9100c 100644 (file)
--- a/fs/bcachefs/six.h
+++ b/fs/bcachefs/six.h
@@ -148,37 +148,116 @@ do {                                                                     \
        __six_lock_init((lock), #lock, &__key, flags);                  \
 } while (0)
 
+bool six_trylock_ip_type(struct six_lock *lock, enum six_lock_type type,
+                        unsigned long ip);
+
+static inline bool six_trylock_type(struct six_lock *lock, enum six_lock_type type)
+{
+       return six_trylock_ip_type(lock, type, _THIS_IP_);
+}
+
+int six_lock_type_ip_waiter(struct six_lock *lock, enum six_lock_type type,
+                           struct six_lock_waiter *wait,
+                           six_lock_should_sleep_fn should_sleep_fn, void *p,
+                           unsigned long ip);
+
+static inline int six_lock_type_waiter(struct six_lock *lock, enum six_lock_type type,
+                               struct six_lock_waiter *wait,
+                               six_lock_should_sleep_fn should_sleep_fn, void *p)
+{
+       return six_lock_type_ip_waiter(lock, type, wait, should_sleep_fn, p, _THIS_IP_);
+}
+
+static inline int six_lock_ip_type(struct six_lock *lock, enum six_lock_type type,
+                               six_lock_should_sleep_fn should_sleep_fn, void *p,
+                               unsigned long ip)
+{
+       struct six_lock_waiter wait;
+
+       return six_lock_type_ip_waiter(lock, type, &wait, should_sleep_fn, p, ip);
+}
+
+static inline int six_lock_type(struct six_lock *lock, enum six_lock_type type,
+                               six_lock_should_sleep_fn should_sleep_fn, void *p)
+{
+       struct six_lock_waiter wait;
+
+       return six_lock_type_ip_waiter(lock, type, &wait, should_sleep_fn, p, _THIS_IP_);
+}
+
+bool six_relock_ip_type(struct six_lock *lock, enum six_lock_type type,
+                       unsigned seq, unsigned long ip);
+
+static inline bool six_relock_type(struct six_lock *lock, enum six_lock_type type,
+                                  unsigned seq)
+{
+       return six_relock_ip_type(lock, type, seq, _THIS_IP_);
+}
+
+void six_unlock_ip_type(struct six_lock *lock, enum six_lock_type type, unsigned long ip);
+
+static inline void six_unlock_type(struct six_lock *lock, enum six_lock_type type)
+{
+       six_unlock_ip_type(lock, type, _THIS_IP_);
+}
+
 #define __SIX_LOCK(type)                                               \
-bool six_trylock_ip_##type(struct six_lock *, unsigned long);          \
-bool six_relock_ip_##type(struct six_lock *, u32, unsigned long);      \
-int six_lock_ip_##type(struct six_lock *, six_lock_should_sleep_fn,    \
-                      void *, unsigned long);                          \
-int six_lock_ip_waiter_##type(struct six_lock *, struct six_lock_waiter *,\
-                       six_lock_should_sleep_fn, void *, unsigned long);\
-void six_unlock_ip_##type(struct six_lock *, unsigned long);           \
+static inline bool six_trylock_ip_##type(struct six_lock *lock, unsigned long ip)\
+{                                                                      \
+       return six_trylock_ip_type(lock, SIX_LOCK_##type, ip);          \
+}                                                                      \
                                                                        \
 static inline bool six_trylock_##type(struct six_lock *lock)           \
 {                                                                      \
-       return six_trylock_ip_##type(lock, _THIS_IP_);                  \
+       return six_trylock_ip_type(lock, SIX_LOCK_##type, _THIS_IP_);   \
+}                                                                      \
+                                                                       \
+static inline int six_lock_ip_waiter_##type(struct six_lock *lock,     \
+                          struct six_lock_waiter *wait,                \
+                          six_lock_should_sleep_fn should_sleep_fn, void *p,\
+                          unsigned long ip)                            \
+{                                                                      \
+       return six_lock_type_ip_waiter(lock, SIX_LOCK_##type, wait, should_sleep_fn, p, ip);\
+}                                                                      \
+                                                                       \
+static inline int six_lock_ip_##type(struct six_lock *lock,            \
+                   six_lock_should_sleep_fn should_sleep_fn, void *p,  \
+                   unsigned long ip)                                   \
+{                                                                      \
+       return six_lock_ip_type(lock, SIX_LOCK_##type, should_sleep_fn, p, ip);\
+}                                                                      \
+                                                                       \
+static inline bool six_relock_ip_##type(struct six_lock *lock, u32 seq, unsigned long ip)\
+{                                                                      \
+       return six_relock_ip_type(lock, SIX_LOCK_##type, seq, ip);      \
 }                                                                      \
+                                                                       \
 static inline bool six_relock_##type(struct six_lock *lock, u32 seq)   \
 {                                                                      \
-       return six_relock_ip_##type(lock, seq, _THIS_IP_);              \
+       return six_relock_ip_type(lock, SIX_LOCK_##type, seq, _THIS_IP_);\
 }                                                                      \
+                                                                       \
 static inline int six_lock_##type(struct six_lock *lock,               \
                                  six_lock_should_sleep_fn fn, void *p)\
 {                                                                      \
        return six_lock_ip_##type(lock, fn, p, _THIS_IP_);              \
 }                                                                      \
+                                                                       \
 static inline int six_lock_waiter_##type(struct six_lock *lock,                \
                        struct six_lock_waiter *wait,                   \
                        six_lock_should_sleep_fn fn, void *p)           \
 {                                                                      \
        return six_lock_ip_waiter_##type(lock, wait, fn, p, _THIS_IP_); \
 }                                                                      \
+                                                                       \
+static inline void six_unlock_ip_##type(struct six_lock *lock, unsigned long ip)       \
+{                                                                      \
+       six_unlock_ip_type(lock, SIX_LOCK_##type, ip);                  \
+}                                                                      \
+                                                                       \
 static inline void six_unlock_##type(struct six_lock *lock)            \
 {                                                                      \
-       return six_unlock_ip_##type(lock, _THIS_IP_);                   \
+       six_unlock_ip_type(lock, SIX_LOCK_##type, _THIS_IP_);           \
 }
 
 __SIX_LOCK(read)
@@ -186,55 +265,6 @@ __SIX_LOCK(intent)
 __SIX_LOCK(write)
 #undef __SIX_LOCK
 
-#define SIX_LOCK_DISPATCH(type, fn, ...)                       \
-       switch (type) {                                         \
-       case SIX_LOCK_read:                                     \
-               return fn##_read(__VA_ARGS__);                  \
-       case SIX_LOCK_intent:                                   \
-               return fn##_intent(__VA_ARGS__);                \
-       case SIX_LOCK_write:                                    \
-               return fn##_write(__VA_ARGS__);                 \
-       default:                                                \
-               BUG();                                          \
-       }
-
-static inline bool six_trylock_type(struct six_lock *lock, enum six_lock_type type)
-{
-       SIX_LOCK_DISPATCH(type, six_trylock, lock);
-}
-
-static inline bool six_relock_type(struct six_lock *lock, enum six_lock_type type,
-                                  unsigned seq)
-{
-       SIX_LOCK_DISPATCH(type, six_relock, lock, seq);
-}
-
-static inline int six_lock_type(struct six_lock *lock, enum six_lock_type type,
-                               six_lock_should_sleep_fn should_sleep_fn, void *p)
-{
-       SIX_LOCK_DISPATCH(type, six_lock, lock, should_sleep_fn, p);
-}
-
-static inline int six_lock_type_ip_waiter(struct six_lock *lock, enum six_lock_type type,
-                               struct six_lock_waiter *wait,
-                               six_lock_should_sleep_fn should_sleep_fn, void *p,
-                               unsigned long ip)
-{
-       SIX_LOCK_DISPATCH(type, six_lock_ip_waiter, lock, wait, should_sleep_fn, p, ip);
-}
-
-static inline int six_lock_type_waiter(struct six_lock *lock, enum six_lock_type type,
-                               struct six_lock_waiter *wait,
-                               six_lock_should_sleep_fn should_sleep_fn, void *p)
-{
-       SIX_LOCK_DISPATCH(type, six_lock_waiter, lock, wait, should_sleep_fn, p);
-}
-
-static inline void six_unlock_type(struct six_lock *lock, enum six_lock_type type)
-{
-       SIX_LOCK_DISPATCH(type, six_unlock, lock);
-}
-
 void six_lock_downgrade(struct six_lock *);
 bool six_lock_tryupgrade(struct six_lock *);
 bool six_trylock_convert(struct six_lock *, enum six_lock_type,