X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fbackend_internal.h;h=dc69ecf39ff41591f3d65908252c4276751c3c6a;hb=85d3c2feb0aca86360e1abcbb66232281308005c;hp=e03d8c0b1b23a1363fdebbe5ed8589223226983c;hpb=85a07c33f3b180d9c1be38832961d0feef66be66;p=lttng-modules.git

diff --git a/lib/ringbuffer/backend_internal.h b/lib/ringbuffer/backend_internal.h
index e03d8c0b..dc69ecf3 100644
--- a/lib/ringbuffer/backend_internal.h
+++ b/lib/ringbuffer/backend_internal.h
@@ -23,6 +23,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <wrapper/compiler.h>
 #include <wrapper/ringbuffer/config.h>
 #include <wrapper/ringbuffer/backend_types.h>
 #include <wrapper/ringbuffer/frontend_types.h>
@@ -171,7 +172,7 @@ void subbuffer_id_set_noref_offset(const struct lib_ring_buffer_config *config,
 		tmp |= offset << SB_ID_OFFSET_SHIFT;
 		tmp |= SB_ID_NOREF_MASK;
 		/* Volatile store, read concurrently by readers. */
-		ACCESS_ONCE(*id) = tmp;
+		WRITE_ONCE(*id, tmp);
 	}
 }
 
@@ -379,7 +380,7 @@ void lib_ring_buffer_clear_noref(const struct lib_ring_buffer_config *config,
 	 * Performing a volatile access to read the sb_pages, because we want to
 	 * read a coherent version of the pointer and the associated noref flag.
 	 */
-	id = ACCESS_ONCE(bufb->buf_wsb[idx].id);
+	id = READ_ONCE(bufb->buf_wsb[idx].id);
 	for (;;) {
 		/* This check is called on the fast path for each record. */
 		if (likely(!subbuffer_id_is_noref(config, id))) {
@@ -448,7 +449,7 @@ int update_read_sb_index(const struct lib_ring_buffer_config *config,
 	if (config->mode == RING_BUFFER_OVERWRITE) {
 		/*
 		 * Exchange the target writer subbuffer with our own unused
-		 * subbuffer. No need to use ACCESS_ONCE() here to read the
+		 * subbuffer. No need to use READ_ONCE() here to read the
 		 * old_wpage, because the value read will be confirmed by the
 		 * following cmpxchg().
 		 */
@@ -478,6 +479,28 @@ int update_read_sb_index(const struct lib_ring_buffer_config *config,
 	return 0;
 }
 
+static inline __attribute__((always_inline))
+void lttng_inline_memcpy(void *dest, const void *src,
+		unsigned long len)
+{
+	switch (len) {
+	case 1:
+		*(uint8_t *) dest = *(const uint8_t *) src;
+		break;
+	case 2:
+		*(uint16_t *) dest = *(const uint16_t *) src;
+		break;
+	case 4:
+		*(uint32_t *) dest = *(const uint32_t *) src;
+		break;
+	case 8:
+		*(uint64_t *) dest = *(const uint64_t *) src;
+		break;
+	default:
+		inline_memcpy(dest, src, len);
+	}
+}
+
 /*
  * Use the architecture-specific memcpy implementation for constant-sized
  * inputs, but rely on an inline memcpy for length statically unknown.
@@ -489,7 +512,7 @@ do {								\
 	if (__builtin_constant_p(len))				\
 		memcpy(dest, src, __len);			\
 	else							\
-		inline_memcpy(dest, src, __len);		\
+		lttng_inline_memcpy(dest, src, __len);		\
 } while (0)
 
 /*