X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=libringbuffer%2Ffrontend_api.h;h=4207574f55e59f36c2aab06a922fcadf4543d6d0;hb=3b8bedd809f1a5b56da5fc101a90b44263b0f473;hp=fd601ce5ca93589636d6932cc435a3a1c8f1677b;hpb=5198080d2234eb06e95d245d0a9747810f496475;p=lttng-ust.git

diff --git a/libringbuffer/frontend_api.h b/libringbuffer/frontend_api.h
index fd601ce5..4207574f 100644
--- a/libringbuffer/frontend_api.h
+++ b/libringbuffer/frontend_api.h
@@ -18,12 +18,11 @@
 #include "frontend.h"
 
 /**
- * lib_ring_buffer_get_cpu - Precedes ring buffer reserve/commit.
+ * lib_ring_buffer_nesting_inc - Ring buffer recursive use protection.
  *
- * Keeps a ring buffer nesting count as supplementary safety net to
- * ensure tracer client code will never trigger an endless recursion.
- * Returns the processor ID on success, -EPERM on failure (nesting count
- * too high).
+ * The rint buffer buffer nesting count is a safety net to ensure tracer
+ * client code will never trigger an endless recursion.
+ * Returns 0 on success, -EPERM on failure (nesting count too high).
  *
  * asm volatile and "memory" clobber prevent the compiler from moving
  * instructions out of the ring buffer nesting count. This is required to ensure
@@ -32,27 +31,22 @@
  * section.
  */
 static inline
-int lib_ring_buffer_get_cpu(const struct lttng_ust_lib_ring_buffer_config *config)
+int lib_ring_buffer_nesting_inc(const struct lttng_ust_lib_ring_buffer_config *config)
 {
-	int cpu, nesting;
+	int nesting;
 
-	cpu = lttng_ust_get_cpu();
 	nesting = ++URCU_TLS(lib_ring_buffer_nesting);
 	cmm_barrier();
-
 	if (caa_unlikely(nesting > 4)) {
 		WARN_ON_ONCE(1);
 		URCU_TLS(lib_ring_buffer_nesting)--;
 		return -EPERM;
-	} else
-		return cpu;
+	}
+	return 0;
 }
 
-/**
- * lib_ring_buffer_put_cpu - Follows ring buffer reserve/commit.
- */
 static inline
-void lib_ring_buffer_put_cpu(const struct lttng_ust_lib_ring_buffer_config *config)
+void lib_ring_buffer_nesting_dec(const struct lttng_ust_lib_ring_buffer_config *config)
 {
 	cmm_barrier();
 	URCU_TLS(lib_ring_buffer_nesting)--;		/* TLS */
@@ -96,7 +90,7 @@ int lib_ring_buffer_try_reserve(const struct lttng_ust_lib_ring_buffer_config *c
 	ctx->slot_size = record_header_size(config, chan, *o_begin,
 					    before_hdr_pad, ctx, client_ctx);
 	ctx->slot_size +=
-		lib_ring_buffer_align(*o_begin + ctx->slot_size,
+		lttng_ust_lib_ring_buffer_align(*o_begin + ctx->slot_size,
 				      ctx->largest_align) + ctx->data_size;
 	if (caa_unlikely((subbuf_offset(*o_begin, chan) + ctx->slot_size)
 		     > chan->backend.subbuf_size))
@@ -140,7 +134,7 @@ int lib_ring_buffer_reserve(const struct lttng_ust_lib_ring_buffer_config *confi
 			    void *client_ctx)
 {
 	struct lttng_ust_lib_ring_buffer_channel *chan = ctx->chan;
-	struct lttng_ust_shm_handle *handle = ctx->handle;
+	struct lttng_ust_shm_handle *handle = ctx->chan->handle;
 	struct lttng_ust_lib_ring_buffer *buf;
 	unsigned long o_begin, o_end, o_old;
 	size_t before_hdr_pad = 0;
@@ -148,10 +142,12 @@ int lib_ring_buffer_reserve(const struct lttng_ust_lib_ring_buffer_config *confi
 	if (caa_unlikely(uatomic_read(&chan->record_disabled)))
 		return -EAGAIN;
 
-	if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
-		buf = shmp(handle, chan->backend.buf[ctx->cpu].shmp);
-	else
+	if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
+		ctx->reserve_cpu = lttng_ust_get_cpu();
+		buf = shmp(handle, chan->backend.buf[ctx->reserve_cpu].shmp);
+	} else {
 		buf = shmp(handle, chan->backend.buf[0].shmp);
+	}
 	if (caa_unlikely(!buf))
 		return -EIO;
 	if (caa_unlikely(uatomic_read(&buf->record_disabled)))
@@ -232,7 +228,7 @@ void lib_ring_buffer_commit(const struct lttng_ust_lib_ring_buffer_config *confi
 			    const struct lttng_ust_lib_ring_buffer_ctx *ctx)
 {
 	struct lttng_ust_lib_ring_buffer_channel *chan = ctx->chan;
-	struct lttng_ust_shm_handle *handle = ctx->handle;
+	struct lttng_ust_shm_handle *handle = ctx->chan->handle;
 	struct lttng_ust_lib_ring_buffer *buf = ctx->buf;
 	unsigned long offset_end = ctx->buf_offset;
 	unsigned long endidx = subbuf_index(offset_end - 1, chan);