rcu.h: remove duplicated fence

[libside.git] / src / rcu.h

diff --git a/src/rcu.h b/src/rcu.h
index 9d335119b9907aabcd069bed3790bcff2b7800e5..69a07c7091ea2bf99e36a951bd30b39a1c500753 100644 (file)
--- a/src/rcu.h
+++ b/src/rcu.h
@@ -81,7 +81,8 @@ void side_rcu_read_begin(struct side_rcu_gp_state *gp_state, struct side_rcu_rea
        read_state->percpu_count = begin_cpu_count = &cpu_gp_state->count[period];
        read_state->cpu = cpu;
        if (side_likely(side_rcu_rseq_membarrier_available &&
-                       !rseq_addv((intptr_t *)&begin_cpu_count->rseq_begin, 1, cpu))) {
+                       !rseq_addv(RSEQ_MO_RELAXED, RSEQ_PERCPU_CPU_ID,
+                                  (intptr_t *)&begin_cpu_count->rseq_begin, 1, cpu))) {
                /*
                 * This compiler barrier (A) is paired with membarrier() at (C),
                 * (D), (E). It effectively upgrades this compiler barrier to a
@@ -129,7 +130,8 @@ void side_rcu_read_end(struct side_rcu_gp_state *gp_state, struct side_rcu_read_
         */
        rseq_barrier();
        if (side_likely(side_rcu_rseq_membarrier_available &&
-                       !rseq_addv((intptr_t *)&begin_cpu_count->rseq_end, 1, cpu))) {
+                       !rseq_addv(RSEQ_MO_RELAXED, RSEQ_PERCPU_CPU_ID,
+                                  (intptr_t *)&begin_cpu_count->rseq_end, 1, cpu))) {
                /*
                 * This barrier (F) is paired with membarrier()
                 * at (G). It orders increment of the begin/end
@@ -141,11 +143,10 @@ void side_rcu_read_end(struct side_rcu_gp_state *gp_state, struct side_rcu_read_
        /* Fallback to atomic increment and SEQ_CST. */
        (void) __atomic_add_fetch(&begin_cpu_count->end, 1, __ATOMIC_SEQ_CST);
        /*
-        * This barrier (F) is paired with SEQ_CST barrier or
-        * membarrier() at (G). It orders increment of the begin/end
-        * counters before load/store to the futex.
+        * This barrier (F) implied by SEQ_CST is paired with SEQ_CST
+        * barrier or membarrier() at (G). It orders increment of the
+        * begin/end counters before load/store to the futex.
         */
-       __atomic_thread_fence(__ATOMIC_SEQ_CST);
 end:
        side_rcu_wake_up_gp(gp_state);
 }