From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Thu, 1 Mar 2012 22:23:47 +0000 (-0500)
Subject: Merge branch 'master' into dev
X-Git-Tag: v2.1.0-rc1~97^2~3
X-Git-Url: http://git.liburcu.org/?a=commitdiff_plain;h=2253b139ffb6a4eca7291b60083cc5206a6e128d;hp=a025b017d398818300ad45c92284116d64c56fc1;p=lttng-ust.git

Merge branch 'master' into dev

Conflicts:
	liblttng-ust/ltt-events.c
	liblttng-ust/lttng-context-vtid.c
	liblttng-ust/lttng-ust-comm.c
	libringbuffer/ring_buffer_frontend.c

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/.gitignore b/.gitignore
index 4239f2e6..076cd007 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,6 +19,7 @@ autom4te.cache/
 /include/lttng/config.h
 /include/lttng/stamp-h2
 /include/lttng/ust-version.h
+/include/lttng/ust-config.h
 /config.h.in
 config/
 config.log
diff --git a/include/lttng/ringbuffer-config.h b/include/lttng/ringbuffer-config.h
index 728738cd..5273f321 100644
--- a/include/lttng/ringbuffer-config.h
+++ b/include/lttng/ringbuffer-config.h
@@ -24,6 +24,7 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <urcu/arch.h>
+#include <string.h>
 #include "lttng/align.h"
 
 struct lttng_ust_lib_ring_buffer;
@@ -122,6 +123,7 @@ struct lttng_ust_lib_ring_buffer_client_cb {
  * RING_BUFFER_WAKEUP_NONE does not perform any wakeup whatsoever. The client
  * has the responsibility to perform wakeups.
  */
+#define LTTNG_UST_RING_BUFFER_CONFIG_PADDING	32
 struct lttng_ust_lib_ring_buffer_config {
 	enum {
 		RING_BUFFER_ALLOC_PER_CPU,
@@ -175,6 +177,7 @@ struct lttng_ust_lib_ring_buffer_config {
 	 * callbacks and update the cb pointers.
 	 */
 	int client_type;
+	char padding[LTTNG_UST_RING_BUFFER_CONFIG_PADDING];
 };
 
 /*
@@ -184,6 +187,7 @@ struct lttng_ust_lib_ring_buffer_config {
  * lib_ring_buffer_try_discard_reserve(), lib_ring_buffer_align_ctx() and
  * lib_ring_buffer_write().
  */
+#define LTTNG_UST_RING_BUFFER_CTX_PADDING	24
 struct lttng_ust_lib_ring_buffer_ctx {
 	/* input received by lib_ring_buffer_reserve(), saved here. */
 	struct channel *chan;		/* channel */
@@ -211,6 +215,7 @@ struct lttng_ust_lib_ring_buffer_ctx {
 					 */
 	uint64_t tsc;			/* time-stamp counter value */
 	unsigned int rflags;		/* reservation flags */
+	char padding[LTTNG_UST_RING_BUFFER_CTX_PADDING];
 };
 
 /**
@@ -235,6 +240,7 @@ void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 	ctx->cpu = cpu;
 	ctx->rflags = 0;
 	ctx->handle = handle;
+	memset(ctx->padding, 0, LTTNG_UST_RING_BUFFER_CTX_PADDING);
 }
 
 /*
diff --git a/include/lttng/tracepoint-types.h b/include/lttng/tracepoint-types.h
index 37a7662b..9b104b07 100644
--- a/include/lttng/tracepoint-types.h
+++ b/include/lttng/tracepoint-types.h
@@ -19,11 +19,14 @@ struct tracepoint_probe {
 	void *data;
 };
 
+#define TRACEPOINT_PADDING	16
 struct tracepoint {
 	const char *name;
 	int state;
 	struct tracepoint_probe *probes;
 	int *tracepoint_provider_ref;
+	const char *signature;
+	char padding[TRACEPOINT_PADDING];
 };
 
 #endif /* _LTTNG_TRACEPOINT_TYPES_H */
diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 5fda51f4..b1c2d360 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -149,7 +149,8 @@ end:											\
 static inline void __tracepoint_register_##_provider##___##_name(char *name,		\
 		void *func, void *data)							\
 {											\
-	__tracepoint_probe_register(name, func, data);					\
+	__tracepoint_probe_register(name, func, data,					\
+		__tracepoint_##_provider##___##_name.signature);			\
 }											\
 static inline void __tracepoint_unregister_##_provider##___##_name(char *name,		\
 		void *func, void *data)							\
@@ -157,7 +158,8 @@ static inline void __tracepoint_unregister_##_provider##___##_name(char *name,
 	__tracepoint_probe_unregister(name, func, data);				\
 }
 
-extern int __tracepoint_probe_register(const char *name, void *func, void *data);
+extern int __tracepoint_probe_register(const char *name, void *func, void *data,
+		const char *signature);
 extern int __tracepoint_probe_unregister(const char *name, void *func, void *data);
 
 /*
@@ -191,10 +193,9 @@ extern struct tracepoint_dlopen tracepoint_dlopen;
  * object from the executable.
  */
 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
-#define _TRACEPOINT_UNDEFINED_REF(provider)
+#define _TRACEPOINT_UNDEFINED_REF(provider)	NULL
 #else	/* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
-#define _TRACEPOINT_UNDEFINED_REF(provider)	\
-	&__tracepoint_provider_##provider,
+#define _TRACEPOINT_UNDEFINED_REF(provider)	&__tracepoint_provider_##provider
 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 
 /*
@@ -202,17 +203,25 @@ extern struct tracepoint_dlopen tracepoint_dlopen;
  * in the __tracepoints_ptrs section.
  * Therefore, this section is _not_ const (read-only).
  */
-#define _DEFINE_TRACEPOINT(provider, name)					\
-	extern int __tracepoint_provider_##provider; 				\
-	static const char __tp_strtab_##provider##___##name[]			\
+#define _TP_EXTRACT_STRING(...)	#__VA_ARGS__
+
+#define _DEFINE_TRACEPOINT(_provider, _name, _args)				\
+	extern int __tracepoint_provider_##_provider; 				\
+	static const char __tp_strtab_##_provider##___##_name[]			\
 		__attribute__((section("__tracepoints_strings"))) =		\
-			#provider ":" #name;					\
-	struct tracepoint __tracepoint_##provider##___##name			\
+			#_provider ":" #_name;					\
+	struct tracepoint __tracepoint_##_provider##___##_name			\
 		__attribute__((section("__tracepoints"))) =			\
-			{ __tp_strtab_##provider##___##name, 0, NULL, _TRACEPOINT_UNDEFINED_REF(provider) };		\
-	static struct tracepoint * __tracepoint_ptr_##provider##___##name	\
+		{								\
+			__tp_strtab_##_provider##___##_name,			\
+			0,							\
+			NULL,							\
+			_TRACEPOINT_UNDEFINED_REF(_provider), 			\
+			_TP_EXTRACT_STRING(_args),				\
+		};								\
+	static struct tracepoint * __tracepoint_ptr_##_provider##___##_name	\
 		__attribute__((used, section("__tracepoints_ptrs"))) =		\
-			&__tracepoint_##provider##___##name;
+			&__tracepoint_##_provider##___##_name;
 
 /*
  * These weak symbols, the constructor, and destructor take care of
@@ -281,7 +290,7 @@ static void __attribute__((destructor)) __tracepoints__destroy(void)
 
 #else /* TRACEPOINT_DEFINE */
 
-#define _DEFINE_TRACEPOINT(provider, name)
+#define _DEFINE_TRACEPOINT(_provider, _name, _args)
 
 #endif /* #else TRACEPOINT_DEFINE */
 
@@ -376,13 +385,13 @@ static void __attribute__((destructor)) __tracepoints__destroy(void)
 
 #define TRACEPOINT_EVENT(provider, name, args, fields)			\
 	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))		\
-	_DEFINE_TRACEPOINT(provider, name)
+	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 
 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 
 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)	\
 	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))		\
-	_DEFINE_TRACEPOINT(provider, name)
+	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 
 #endif /* #ifndef TRACEPOINT_EVENT */
 
diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 96435c48..f1ef8c91 100644
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -32,6 +32,11 @@ struct ltt_channel;
 struct ltt_session;
 struct lttng_ust_lib_ring_buffer_ctx;
 
+/*
+ * Data structures used by tracepoint event declarations, and by the
+ * tracer. Those structures have padding for future extension.
+ */
+
 /*
  * LTTng client type enumeration. Used by the consumer to map the
  * callbacks from its own address space.
@@ -64,9 +69,11 @@ enum lttng_string_encodings {
 	NR_STRING_ENCODINGS,
 };
 
+#define LTTNG_UST_ENUM_ENTRY_PADDING	16
 struct lttng_enum_entry {
 	unsigned long long start, end;	/* start and end are inclusive */
 	const char *string;
+	char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
 };
 
 #define __type_integer(_type, _byte_order, _base, _encoding)	\
@@ -83,6 +90,7 @@ struct lttng_enum_entry {
 		},						\
 	}							\
 
+#define LTTNG_UST_INTEGER_TYPE_PADDING	24
 struct lttng_integer_type {
 	unsigned int size;		/* in bits */
 	unsigned short alignment;	/* in bits */
@@ -90,6 +98,7 @@ struct lttng_integer_type {
 	unsigned int reverse_byte_order:1;
 	unsigned int base;		/* 2, 8, 10, 16, for pretty print */
 	enum lttng_string_encodings encoding;
+	char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 };
 
 /*
@@ -114,13 +123,16 @@ struct lttng_integer_type {
 		},						\
 	}							\
 
+#define LTTNG_UST_FLOAT_TYPE_PADDING	24
 struct lttng_float_type {
 	unsigned int exp_dig;		/* exponent digits, in bits */
 	unsigned int mant_dig;		/* mantissa digits, in bits */
 	unsigned short alignment;	/* in bits */
 	unsigned int reverse_byte_order:1;
+	char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 };
 
+#define LTTNG_UST_BASIC_TYPE_PADDING	128
 union _lttng_basic_type {
 	struct lttng_integer_type integer;
 	struct {
@@ -130,6 +142,7 @@ union _lttng_basic_type {
 		enum lttng_string_encodings encoding;
 	} string;
 	struct lttng_float_type _float;
+	char padding[LTTNG_UST_BASIC_TYPE_PADDING];
 };
 
 struct lttng_basic_type {
@@ -139,6 +152,7 @@ struct lttng_basic_type {
 	} u;
 };
 
+#define LTTNG_UST_TYPE_PADDING	128
 struct lttng_type {
 	enum abstract_types atype;
 	union {
@@ -151,23 +165,29 @@ struct lttng_type {
 			struct lttng_basic_type length_type;
 			struct lttng_basic_type elem_type;
 		} sequence;
+		char padding[LTTNG_UST_TYPE_PADDING];
 	} u;
 };
 
+#define LTTNG_UST_ENUM_TYPE_PADDING	24
 struct lttng_enum {
 	const char *name;
 	struct lttng_type container_type;
 	const struct lttng_enum_entry *entries;
 	unsigned int len;
+	char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 };
 
 /* Event field description */
 
+#define LTTNG_UST_EVENT_FIELD_PADDING	32
 struct lttng_event_field {
 	const char *name;
 	struct lttng_type type;
+	char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 };
 
+#define LTTNG_UST_CTX_FIELD_PADDING	40
 struct lttng_ctx_field {
 	struct lttng_event_field event_field;
 	size_t (*get_size)(size_t offset);
@@ -175,16 +195,42 @@ struct lttng_ctx_field {
 		       struct lttng_ust_lib_ring_buffer_ctx *ctx,
 		       struct ltt_channel *chan);
 	union {
+		char padding[LTTNG_UST_CTX_FIELD_PADDING];
 	} u;
 	void (*destroy)(struct lttng_ctx_field *field);
 };
 
+#define LTTNG_UST_CTX_PADDING	24
 struct lttng_ctx {
 	struct lttng_ctx_field *fields;
 	unsigned int nr_fields;
 	unsigned int allocated_fields;
+	char padding[LTTNG_UST_CTX_PADDING];
+};
+
+#define LTTNG_UST_EVENT_DESC_PADDING	40
+struct lttng_event_desc {
+	const char *name;
+	void *probe_callback;
+	const struct lttng_event_ctx *ctx;	/* context */
+	const struct lttng_event_field *fields;	/* event payload */
+	unsigned int nr_fields;
+	const int **loglevel;
+	const char *signature;	/* Argument types/names received */
+	char padding[LTTNG_UST_EVENT_DESC_PADDING];
+};
+
+#define LTTNG_UST_PROBE_DESC_PADDING	40
+struct lttng_probe_desc {
+	const char *provider;
+	const struct lttng_event_desc **event_desc;
+	unsigned int nr_events;
+	struct cds_list_head head;		/* chain registered probes */
+	char padding[LTTNG_UST_PROBE_DESC_PADDING];
 };
 
+/* Data structures used by the tracer. */
+
 /*
  * Entry describing a per-session active wildcard, along with the event
  * attribute and channel information configuring the events that need to
@@ -214,22 +260,6 @@ struct wildcard_entry {
 	char name[0];
 };
 
-struct lttng_event_desc {
-	const char *name;
-	void *probe_callback;
-	const struct lttng_event_ctx *ctx;	/* context */
-	const struct lttng_event_field *fields;	/* event payload */
-	unsigned int nr_fields;
-	const int **loglevel;
-};
-
-struct lttng_probe_desc {
-	const char *provider;
-	const struct lttng_event_desc **event_desc;
-	unsigned int nr_events;
-	struct cds_list_head head;		/* chain registered probes */
-};
-
 struct tp_list_entry {
 	struct lttng_ust_tracepoint_iter tp;
 	struct cds_list_head head;
diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h
index 18aa4e44..1dffd946 100644
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -76,7 +76,7 @@
 			 _TP_PARAMS(_args),			\
 			 _TP_PARAMS(_fields))			\
 	TRACEPOINT_EVENT_INSTANCE(_provider, _name, _name,	\
-			 _TP_PARAMS(args))
+			 _TP_PARAMS(_args))
 
 /* Helpers */
 #define _TP_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
@@ -433,6 +433,25 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
 
 #undef __get_dynamic_len
 
+/*
+ * Stage 5.1 of tracepoint event generation.
+ *
+ * Create probe signature
+ */
+
+/* Reset all macros within TRACEPOINT_EVENT */
+#include <lttng/ust-tracepoint-event-reset.h>
+
+#undef TP_ARGS
+#define TP_ARGS(args...) #args
+
+#undef TRACEPOINT_EVENT_CLASS
+#define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)	\
+const char __tp_event_signature___##_provider##___##_name[] = 		\
+		_args;
+
+#include TRACEPOINT_INCLUDE
+
 /*
  * Stage 6 of tracepoint event generation.
  *
@@ -475,6 +494,7 @@ const struct lttng_event_desc __event_desc___##_provider##_##_name = {	       \
 	.probe_callback = (void *) &__event_probe__##_provider##___##_template,\
 	.nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template), \
 	.loglevel = &__ref_loglevel___##_provider##___##_name,		       \
+	.signature = __tp_event_signature___##_provider##___##_template,       \
 };
 
 #include TRACEPOINT_INCLUDE
diff --git a/liblttng-ust/ltt-events.c b/liblttng-ust/ltt-events.c
index d6f569e8..dcc64a55 100644
--- a/liblttng-ust/ltt-events.c
+++ b/liblttng-ust/ltt-events.c
@@ -277,7 +277,7 @@ int pending_probe_fix_events(const struct lttng_event_desc *desc)
 		remove_pending_probe(e);
 		ret |= __tracepoint_probe_register(name,
 				event->desc->probe_callback,
-				event);
+				event, event->desc->signature);
 		if (ret)
 			continue;
 		event->id = chan->free_event_id++;
@@ -552,7 +552,7 @@ int ltt_event_create(struct ltt_channel *chan,
 		if (event->desc) {
 			ret = __tracepoint_probe_register(event_param->name,
 					event->desc->probe_callback,
-					event);
+					event, event->desc->signature);
 			if (ret)
 				goto register_error;
 			event->id = chan->free_event_id++;
diff --git a/liblttng-ust/ltt-probes.c b/liblttng-ust/ltt-probes.c
index 474ac454..0de5c6a4 100644
--- a/liblttng-ust/ltt-probes.c
+++ b/liblttng-ust/ltt-probes.c
@@ -99,7 +99,12 @@ desc_added:
 	 * fix the events awaiting probe load.
 	 */
 	for (i = 0; i < desc->nr_events; i++) {
-		ret = pending_probe_fix_events(desc->event_desc[i]);
+		const struct lttng_event_desc *ed;
+
+		ed = desc->event_desc[i];
+		DBG("Registered event probe \"%s\" with signature \"%s\"",
+			ed->name, ed->signature);
+		ret = pending_probe_fix_events(ed);
 		assert(!ret);
 	}
 end:
diff --git a/liblttng-ust/tracepoint-internal.h b/liblttng-ust/tracepoint-internal.h
index d302e6ba..98688ace 100644
--- a/liblttng-ust/tracepoint-internal.h
+++ b/liblttng-ust/tracepoint-internal.h
@@ -31,8 +31,11 @@ struct tracepoint_lib {
 	int tracepoints_count;
 };
 
-extern int tracepoint_probe_register_noupdate(const char *name, void *callback, void *priv);
-extern int tracepoint_probe_unregister_noupdate(const char *name, void *callback, void *priv);
+extern int tracepoint_probe_register_noupdate(const char *name,
+		void *callback, void *priv,
+		const char *signature);
+extern int tracepoint_probe_unregister_noupdate(const char *name,
+		void *callback, void *priv);
 extern void tracepoint_probe_update_all(void);
 
 /*
diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c
index 7144fab4..a14c8b34 100644
--- a/liblttng-ust/tracepoint.c
+++ b/liblttng-ust/tracepoint.c
@@ -94,6 +94,7 @@ struct tracepoint_entry {
 	struct cds_hlist_node hlist;
 	struct tracepoint_probe *probes;
 	int refcount;	/* Number of times armed. 0 if disarmed. */
+	const char *signature;
 	char name[0];
 };
 
@@ -243,7 +244,8 @@ static struct tracepoint_entry *get_tracepoint(const char *name)
  * Add the tracepoint to the tracepoint hash table. Must be called with
  * tracepoint mutex held.
  */
-static struct tracepoint_entry *add_tracepoint(const char *name)
+static struct tracepoint_entry *add_tracepoint(const char *name,
+		const char *signature)
 {
 	struct cds_hlist_head *head;
 	struct cds_hlist_node *node;
@@ -274,6 +276,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name)
 	e->name[name_len] = '\0';
 	e->probes = NULL;
 	e->refcount = 0;
+	e->signature = signature;
 	cds_hlist_add_head(&e->hlist, head);
 	return e;
 }
@@ -295,6 +298,23 @@ static void set_tracepoint(struct tracepoint_entry **entry,
 	struct tracepoint *elem, int active)
 {
 	WARN_ON(strncmp((*entry)->name, elem->name, LTTNG_UST_SYM_NAME_LEN - 1) != 0);
+	/*
+	 * Check that signatures match before connecting a probe to a
+	 * tracepoint. Warn the user if they don't.
+	 */
+	if (strcmp(elem->signature, (*entry)->signature) != 0) {
+		static int warned = 0;
+
+		/* Only print once, don't flood console. */
+		if (!warned) {
+			WARN("Tracepoint signature mismatch, not enabling one or more tracepoints. Ensure that the tracepoint probes prototypes match the application.");
+			WARN("Tracepoint \"%s\" signatures: call: \"%s\" vs probe: \"%s\".",
+				elem->name, elem->signature, (*entry)->signature);
+			warned = 1;
+		}
+		/* Don't accept connecting non-matching signatures. */
+		return;
+	}
 
 	/*
 	 * rcu_assign_pointer has a cmm_smp_wmb() which makes sure that the new
@@ -370,14 +390,15 @@ static void tracepoint_update_probes(void)
 }
 
 static struct tracepoint_probe *
-tracepoint_add_probe(const char *name, void *probe, void *data)
+tracepoint_add_probe(const char *name, void *probe, void *data,
+		const char *signature)
 {
 	struct tracepoint_entry *entry;
 	struct tracepoint_probe *old;
 
 	entry = get_tracepoint(name);
 	if (!entry) {
-		entry = add_tracepoint(name);
+		entry = add_tracepoint(name, signature);
 		if (IS_ERR(entry))
 			return (struct tracepoint_probe *)entry;
 	}
@@ -396,7 +417,8 @@ tracepoint_add_probe(const char *name, void *probe, void *data)
  * The probe address must at least be aligned on the architecture pointer size.
  * Called with the tracepoint mutex held.
  */
-int __tracepoint_probe_register(const char *name, void *probe, void *data)
+int __tracepoint_probe_register(const char *name, void *probe, void *data,
+		const char *signature)
 {
 	void *old;
 	int ret = 0;
@@ -404,7 +426,7 @@ int __tracepoint_probe_register(const char *name, void *probe, void *data)
 	DBG("Registering probe to tracepoint %s", name);
 
 	pthread_mutex_lock(&tracepoint_mutex);
-	old = tracepoint_add_probe(name, probe, data);
+	old = tracepoint_add_probe(name, probe, data, signature);
 	if (IS_ERR(old)) {
 		ret = PTR_ERR(old);
 		goto end;
@@ -477,13 +499,13 @@ static void tracepoint_add_old_probes(void *old)
  * caller must call tracepoint_probe_update_all()
  */
 int tracepoint_probe_register_noupdate(const char *name, void *probe,
-				       void *data)
+				       void *data, const char *signature)
 {
 	void *old;
 	int ret = 0;
 
 	pthread_mutex_lock(&tracepoint_mutex);
-	old = tracepoint_add_probe(name, probe, data);
+	old = tracepoint_add_probe(name, probe, data, signature);
 	if (IS_ERR(old)) {
 		ret = PTR_ERR(old);
 		goto end;
diff --git a/libringbuffer/backend_types.h b/libringbuffer/backend_types.h
index 3d8bd3cb..81e67119 100644
--- a/libringbuffer/backend_types.h
+++ b/libringbuffer/backend_types.h
@@ -15,12 +15,14 @@
 #include "shm_internal.h"
 #include "vatomic.h"
 
+#define RB_BACKEND_PAGES_PADDING	16
 struct lttng_ust_lib_ring_buffer_backend_pages {
 	unsigned long mmap_offset;	/* offset of the subbuffer in mmap */
 	union v_atomic records_commit;	/* current records committed count */
 	union v_atomic records_unread;	/* records to read */
 	unsigned long data_size;	/* Amount of data to read from subbuf */
 	DECLARE_SHMP(char, p);		/* Backing memory map */
+	char padding[RB_BACKEND_PAGES_PADDING];
 };
 
 struct lttng_ust_lib_ring_buffer_backend_subbuffer {
@@ -38,6 +40,7 @@ struct lttng_ust_lib_ring_buffer_backend_pages_shmp {
 	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages, shmp);
 };
 
+#define RB_BACKEND_RING_BUFFER_PADDING		64
 struct lttng_ust_lib_ring_buffer_backend {
 	/* Array of ring_buffer_backend_subbuffer for writer */
 	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_subbuffer, buf_wsb);
@@ -54,12 +57,14 @@ struct lttng_ust_lib_ring_buffer_backend {
 	int cpu;			/* This buffer's cpu. -1 if global. */
 	union v_atomic records_read;	/* Number of records read */
 	unsigned int allocated:1;	/* is buffer allocated ? */
+	char padding[RB_BACKEND_RING_BUFFER_PADDING];
 };
 
 struct lttng_ust_lib_ring_buffer_shmp {
 	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, shmp); /* Channel per-cpu buffers */
 };
 
+#define RB_BACKEND_CHANNEL_PADDING	64
 struct channel_backend {
 	unsigned long buf_size;		/* Size of the buffer */
 	unsigned long subbuf_size;	/* Sub-buffer size */
@@ -75,6 +80,7 @@ struct channel_backend {
 	DECLARE_SHMP(void *, priv_data);/* Client-specific information */
 	struct lttng_ust_lib_ring_buffer_config config; /* Ring buffer configuration */
 	char name[NAME_MAX];		/* Channel name */
+	char padding[RB_BACKEND_CHANNEL_PADDING];
 	struct lttng_ust_lib_ring_buffer_shmp buf[];
 };
 
diff --git a/libringbuffer/frontend_types.h b/libringbuffer/frontend_types.h
index 961c90e5..1d47b275 100644
--- a/libringbuffer/frontend_types.h
+++ b/libringbuffer/frontend_types.h
@@ -34,6 +34,7 @@
 enum switch_mode { SWITCH_ACTIVE, SWITCH_FLUSH };
 
 /* channel: collection of per-cpu ring buffers. */
+#define RB_CHANNEL_PADDING	64
 struct channel {
 	int record_disabled;
 	unsigned long commit_count_mask;	/*
@@ -53,20 +54,26 @@ struct channel {
 	 * be last member.
 	 */
 	struct channel_backend backend;		/* Associated backend */
+	char padding[RB_CHANNEL_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
 /* Per-subbuffer commit counters used on the hot path */
+#define RB_COMMIT_COUNT_HOT_PADDING	16
 struct commit_counters_hot {
 	union v_atomic cc;		/* Commit counter */
 	union v_atomic seq;		/* Consecutive commits */
+	char padding[RB_COMMIT_COUNT_HOT_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
 /* Per-subbuffer commit counters used only on cold paths */
+#define RB_COMMIT_COUNT_COLD_PADDING	24
 struct commit_counters_cold {
 	union v_atomic cc_sb;		/* Incremented _once_ at sb switch */
+	char padding[RB_COMMIT_COUNT_COLD_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
 /* ring buffer state */
+#define RB_RING_BUFFER_PADDING		64
 struct lttng_ust_lib_ring_buffer {
 	/* First 32 bytes cache-hot cacheline */
 	union v_atomic offset;		/* Current offset in the buffer */
@@ -109,6 +116,7 @@ struct lttng_ust_lib_ring_buffer {
 		read_timer_enabled:1;	/* Protected by ring_buffer_nohz_lock */
 	/* shmp pointer to self */
 	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, self);
+	char padding[RB_RING_BUFFER_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
 static inline