Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / include / linux / percpu.h

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 6aedd71..e436dbd 100644 (file)
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -8,7 +8,7 @@
 
 /* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
 #ifndef PERCPU_ENOUGH_ROOM
-#define PERCPU_ENOUGH_ROOM 32768
+#define PERCPU_ENOUGH_ROOM 65536
 #endif
 
 /* Must be an lvalue. */
@@ -19,13 +19,12 @@
 
 struct percpu_data {
        void *ptrs[NR_CPUS];
-       void *blkp;
 };
 
 /* 
  * Use this to get to a cpu's version of the per-cpu object allocated using
- * alloc_percpu.  If you want to get "this cpu's version", maybe you want
- * to use get_cpu_ptr... 
+ * alloc_percpu.  Non-atomic access to the current CPU's version should
+ * probably be combined with get_cpu()/put_cpu().
  */ 
 #define per_cpu_ptr(ptr, cpu)                   \
 ({                                              \
@@ -33,14 +32,14 @@ struct percpu_data {
         (__typeof__(ptr))__p->ptrs[(cpu)];     \
 })
 
-extern void *__alloc_percpu(size_t size, size_t align);
+extern void *__alloc_percpu(size_t size);
 extern void free_percpu(const void *);
 
 #else /* CONFIG_SMP */
 
-#define per_cpu_ptr(ptr, cpu) (ptr)
+#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
 
-static inline void *__alloc_percpu(size_t size, size_t align)
+static inline void *__alloc_percpu(size_t size)
 {
        void *ret = kmalloc(size, GFP_KERNEL);
        if (ret)
@@ -55,29 +54,6 @@ static inline void free_percpu(const void *ptr)
 #endif /* CONFIG_SMP */
 
 /* Simple wrapper for the common case: zeros memory. */
-#define alloc_percpu(type) \
-       ((type *)(__alloc_percpu(sizeof(type), __alignof__(type))))
-
-/* 
- * Use these with alloc_percpu. If
- * 1. You want to operate on memory allocated by alloc_percpu (dereference
- *    and read/modify/write)  AND 
- * 2. You want "this cpu's version" of the object AND 
- * 3. You want to do this safely since:
- *    a. On multiprocessors, you don't want to switch between cpus after 
- *    you've read the current processor id due to preemption -- this would 
- *    take away the implicit  advantage to not have any kind of traditional 
- *    serialization for per-cpu data
- *    b. On uniprocessors, you don't want another kernel thread messing
- *    up with the same per-cpu data due to preemption
- *    
- * So, Use get_cpu_ptr to disable preemption and get pointer to the 
- * local cpu version of the per-cpu object. Use put_cpu_ptr to enable
- * preemption.  Operations on per-cpu data between get_ and put_ is
- * then considered to be safe. And ofcourse, "Thou shalt not sleep between 
- * get_cpu_ptr and put_cpu_ptr"
- */
-#define get_cpu_ptr(ptr) per_cpu_ptr(ptr, get_cpu())
-#define put_cpu_ptr(ptr) put_cpu()
+#define alloc_percpu(type)     ((type *)(__alloc_percpu(sizeof(type))))
 
 #endif /* __LINUX_PERCPU_H */