X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=urcu-bp.c;h=9c7da3d8d235355246de95dfb5de87c8dcc1fec8;hb=refs%2Fheads%2Fstable-0.9;hp=6b78af8bd8dfc77545a8a11adcfec997434e57bd;hpb=f541831e757bc5e0143550f5d686bed0de7d41b7;p=userspace-rcu.git

diff --git a/urcu-bp.c b/urcu-bp.c
index 6b78af8..9c7da3d 100644
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -36,6 +36,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
 
+#include "urcu/arch.h"
 #include "urcu/wfcqueue.h"
 #include "urcu/map/urcu-bp.h"
 #include "urcu/static/urcu-bp.h"
@@ -94,16 +95,9 @@ void *mremap_wrapper(void *old_address, size_t old_size,
 static
 int rcu_bp_refcount;
 
-/*
- * RCU_MEMBARRIER is only possibly available on Linux.
- */
-#ifdef __linux__
-#include <urcu/syscall-compat.h>
-#endif
-
-/* If the headers do not support SYS_membarrier, fall back on RCU_MB */
-#ifdef SYS_membarrier
-# define membarrier(...)		syscall(SYS_membarrier, __VA_ARGS__)
+/* If the headers do not support membarrier system call, fall back smp_mb. */
+#ifdef __NR_membarrier
+# define membarrier(...)		syscall(__NR_membarrier, __VA_ARGS__)
 #else
 # define membarrier(...)		-ENOSYS
 #endif
@@ -379,13 +373,14 @@ void expand_arena(struct registry_arena *arena)
 			sizeof(struct registry_chunk)
 			+ sizeof(struct rcu_reader));
 		new_chunk_len = ARENA_INIT_ALLOC;
-		new_chunk = mmap(NULL, new_chunk_len,
+		new_chunk = (struct registry_chunk *) mmap(NULL,
+			new_chunk_len,
 			PROT_READ | PROT_WRITE,
 			MAP_ANONYMOUS | MAP_PRIVATE,
 			-1, 0);
 		if (new_chunk == MAP_FAILED)
 			abort();
-		bzero(new_chunk, new_chunk_len);
+		memset(new_chunk, 0, new_chunk_len);
 		new_chunk->data_len =
 			new_chunk_len - sizeof(struct registry_chunk);
 		cds_list_add_tail(&new_chunk->node, &arena->chunk_list);
@@ -405,7 +400,7 @@ void expand_arena(struct registry_arena *arena)
 	if (new_chunk != MAP_FAILED) {
 		/* Should not have moved. */
 		assert(new_chunk == last_chunk);
-		bzero((char *) last_chunk + old_chunk_len,
+		memset((char *) last_chunk + old_chunk_len, 0,
 			new_chunk_len - old_chunk_len);
 		last_chunk->data_len =
 			new_chunk_len - sizeof(struct registry_chunk);
@@ -413,13 +408,14 @@ void expand_arena(struct registry_arena *arena)
 	}
 
 	/* Remap did not succeed, we need to add a new chunk. */
-	new_chunk = mmap(NULL, new_chunk_len,
+	new_chunk = (struct registry_chunk *) mmap(NULL,
+		new_chunk_len,
 		PROT_READ | PROT_WRITE,
 		MAP_ANONYMOUS | MAP_PRIVATE,
 		-1, 0);
 	if (new_chunk == MAP_FAILED)
 		abort();
-	bzero(new_chunk, new_chunk_len);
+	memset(new_chunk, 0, new_chunk_len);
 	new_chunk->data_len =
 		new_chunk_len - sizeof(struct registry_chunk);
 	cds_list_add_tail(&new_chunk->node, &arena->chunk_list);
@@ -585,6 +581,17 @@ void urcu_bp_thread_exit_notifier(void *rcu_key)
 	rcu_bp_unregister(rcu_key);
 }
 
+static
+void rcu_sys_membarrier_status(int available)
+{
+	/*
+	 * membarrier has blocking behavior, which changes the
+	 * application behavior too much compared to using barriers when
+	 * synchronize_rcu is used repeatedly (without using call_rcu).
+	 * Don't use membarrier for now.
+	 */
+}
+
 static
 void rcu_bp_init(void)
 {
@@ -597,9 +604,8 @@ void rcu_bp_init(void)
 		if (ret)
 			abort();
 		ret = membarrier(MEMBARRIER_CMD_QUERY, 0);
-		if (ret >= 0 && (ret & MEMBARRIER_CMD_SHARED)) {
-			urcu_bp_has_sys_membarrier = 1;
-		}
+		rcu_sys_membarrier_status(ret >= 0
+				&& (ret & MEMBARRIER_CMD_SHARED));
 		initialized = 1;
 	}
 	mutex_unlock(&init_lock);
@@ -615,9 +621,10 @@ void rcu_bp_exit(void)
 
 		cds_list_for_each_entry_safe(chunk, tmp,
 				&registry_arena.chunk_list, node) {
-			munmap(chunk, chunk->data_len
+			munmap((void *) chunk, chunk->data_len
 					+ sizeof(struct registry_chunk));
 		}
+		CDS_INIT_LIST_HEAD(&registry_arena.chunk_list);
 		ret = pthread_key_delete(urcu_bp_key);
 		if (ret)
 			abort();