mm: move vmscan writes and file write accounting to the node

[cascardo/linux.git] / include / linux / rcupdate.h

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 5f1533e..1aa62e1 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -45,6 +45,7 @@
 #include <linux/bug.h>
 #include <linux/compiler.h>
 #include <linux/ktime.h>
+#include <linux/irqflags.h>
 
 #include <asm/barrier.h>
 
@@ -379,12 +380,13 @@ static inline void rcu_init_nohz(void)
  * in the inner idle loop.
  *
  * This macro provides the way out:  RCU_NONIDLE(do_something_with_RCU())
- * will tell RCU that it needs to pay attending, invoke its argument
- * (in this example, a call to the do_something_with_RCU() function),
+ * will tell RCU that it needs to pay attention, invoke its argument
+ * (in this example, calling the do_something_with_RCU() function),
  * and then tell RCU to go back to ignoring this CPU.  It is permissible
- * to nest RCU_NONIDLE() wrappers, but the nesting level is currently
- * quite limited.  If deeper nesting is required, it will be necessary
- * to adjust DYNTICK_TASK_NESTING_VALUE accordingly.
+ * to nest RCU_NONIDLE() wrappers, but not indefinitely (but the limit is
+ * on the order of a million or so, even on 32-bit systems).  It is
+ * not legal to block within RCU_NONIDLE(), nor is it permissible to
+ * transfer control either into or out of RCU_NONIDLE()'s statement.
  */
 #define RCU_NONIDLE(a) \
        do { \
@@ -611,6 +613,12 @@ static inline void rcu_preempt_sleep_check(void)
        rcu_dereference_sparse(p, space); \
        ((typeof(*p) __force __kernel *)(p)); \
 })
+#define rcu_dereference_raw(p) \
+({ \
+       /* Dependency order vs. p above. */ \
+       typeof(p) ________p1 = lockless_dereference(p); \
+       ((typeof(*p) __force __kernel *)(________p1)); \
+})
 
 /**
  * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
@@ -649,7 +657,16 @@ static inline void rcu_preempt_sleep_check(void)
  * please be careful when making changes to rcu_assign_pointer() and the
  * other macros that it invokes.
  */
-#define rcu_assign_pointer(p, v) smp_store_release(&p, RCU_INITIALIZER(v))
+#define rcu_assign_pointer(p, v)                                             \
+({                                                                           \
+       uintptr_t _r_a_p__v = (uintptr_t)(v);                                 \
+                                                                             \
+       if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL)        \
+               WRITE_ONCE((p), (typeof(p))(_r_a_p__v));                      \
+       else                                                                  \
+               smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
+       _r_a_p__v;                                                            \
+})
 
 /**
  * rcu_access_pointer() - fetch RCU pointer with no dereferencing
@@ -729,8 +746,6 @@ static inline void rcu_preempt_sleep_check(void)
        __rcu_dereference_check((p), (c) || rcu_read_lock_sched_held(), \
                                __rcu)
 
-#define rcu_dereference_raw(p) rcu_dereference_check(p, 1) /*@@@ needed? @@@*/
-
 /*
  * The tracing infrastructure traces RCU (we want that), but unfortunately
  * some of the RCU checks causes tracing to lock up the system.