net/failsafe: mitigate data plane atomic operations

Fail-safe uses atomic operations to protect sub-device close operation
calling by host thread in removal time while the removed sub-device
burst functions are still in process by application threads.

Using "set" atomic operations is a little bit more efficient than "add"
or "sub" atomic operations because "set" shouldn't read the value and
in fact, it does not need a special atomic mechanism in x86 platforms.

Replace "add 1" and "sub 1" atomic operations by "set 1" and "set 0"
atomic operations.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Gaetan Rivet <gaetan.rivet@6wind.com>

diff --git a/drivers/net/failsafe/failsafe_private.h b/drivers/net/failsafe/failsafe_private.h
index d81cc3c..4196ece 100644 (file)
--- a/drivers/net/failsafe/failsafe_private.h
+++ b/drivers/net/failsafe/failsafe_private.h
@@ -269,13 +269,13 @@ extern int mac_from_arg;
  * a: (rte_atomic64_t)
  */
 #define FS_ATOMIC_P(a) \
-       rte_atomic64_add(&(a), 1)
+       rte_atomic64_set(&(a), 1)
 
 /**
  * a: (rte_atomic64_t)
  */
 #define FS_ATOMIC_V(a) \
-       rte_atomic64_sub(&(a), 1)
+       rte_atomic64_set(&(a), 0)
 
 /**
  * s: (struct sub_device *)