Andrew Morton a écrit :
Eric Dumazet <[EMAIL PROTECTED]> wrote:
An advantage of retaining a spinlock in percpu_counter is that if accuracy
is needed at a low rate (say, /proc reading) we can take the lock and then
go spill each CPU's local count into the main one. It would need to be a
very low rate though. Or we make the cpu-local counters atomic too.
We might use atomic_long_t only (and no spinlocks)
Yup, that's it.
Something like this ?
It'd be a lot neater if we had atomic_long_xchg().
You are my guest :)
[PATCH] Add atomic_long_xchg() and atomic_long_cmpxchg() wrappers
Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]>
--- a/include/asm-generic/atomic.h 2006-01-28 02:59:49.000000000 +0100
+++ b/include/asm-generic/atomic.h 2006-01-28 02:57:36.000000000 +0100
@@ -66,6 +66,18 @@
atomic64_sub(i, v);
}
+static inline long atomic_long_xchg(atomic_long_t *l, long val)
+{
+ atomic64_t *v = (atomic64_t *)l;
+ return atomic64_xchg(v, val);
+}
+
+static inline long atomic_long_cmpxchg(atomic_long_t *l, long old, long new)
+{
+ atomic64_t *v = (atomic64_t *)l;
+ return atomic64_cmpxchg(v, old, new);
+}
+
#else
typedef atomic_t atomic_long_t;
@@ -113,5 +125,17 @@
atomic_sub(i, v);
}
+static inline long atomic_long_xchg(atomic_long_t *l, long val)
+{
+ atomic_t *v = (atomic_t *)l;
+ return atomic_xchg(v, val);
+}
+
+static inline long atomic_long_cmpxchg(atomic_long_t *l, long old, long new)
+{
+ atomic_t *v = (atomic_t *)l;
+ return atomic_cmpxchg(v, old, new);
+}
+
#endif
#endif
