X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_backend.c;h=40fae8017aed823401ae85a328be5bb8833a8231;hb=82ee1ee4a147de031957bfcb8a1908b926bac603;hp=3a667adce53c8ccdda4f15b872c13d054907f7ed;hpb=a9ff648cc4cc06d28b522d705c467d45ab916a9d;p=lttng-ust.git

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 3a667adc..40fae801 100644
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -19,6 +19,7 @@
  */
 
 #define _GNU_SOURCE
+#include <unistd.h>
 #include <urcu/arch.h>
 #include <limits.h>
 
@@ -29,8 +30,6 @@
 #include "smp.h"
 #include "shm.h"
 
-#define UINT_MAX_STR_LEN 11	/* includes \0 */
-
 /**
  * lib_ring_buffer_backend_allocate - allocate a channel buffer
  * @config: ring buffer instance configuration
@@ -51,6 +50,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
 	unsigned long subbuf_size, mmap_offset = 0;
 	unsigned long num_subbuf_alloc;
 	unsigned long i;
+	long page_size;
 
 	subbuf_size = chanb->subbuf_size;
 	num_subbuf_alloc = num_subbuf;
@@ -58,6 +58,11 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
 	if (extra_reader_sb)
 		num_subbuf_alloc++;
 
+	page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size <= 0) {
+		goto page_size_error;
+	}
+
 	align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
 	set_shmp(bufb->array, zalloc_shm(shmobj,
 			sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc));
@@ -66,9 +71,9 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
 
 	/*
 	 * This is the largest element (the buffer pages) which needs to
-	 * be aligned on PAGE_SIZE.
+	 * be aligned on page size.
 	 */
-	align_shm(shmobj, PAGE_SIZE);
+	align_shm(shmobj, page_size);
 	set_shmp(bufb->memory_map, zalloc_shm(shmobj,
 			subbuf_size * num_subbuf_alloc));
 	if (caa_unlikely(!shmp(handle, bufb->memory_map)))
@@ -124,6 +129,7 @@ free_array:
 memory_map_error:
 	/* bufb->array will be freed by shm teardown */
 array_error:
+page_size_error:
 	return -ENOMEM;
 }
 
@@ -197,10 +203,10 @@ void channel_backend_reset(struct channel_backend *chanb)
  * @name: channel name
  * @config: client ring buffer configuration
  * @parent: dentry of parent directory, %NULL for root directory
- * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
+ * @subbuf_size: size of sub-buffers (> page size, power of 2)
  * @num_subbuf: number of sub-buffers (power of 2)
  * @lttng_ust_shm_handle: shared memory handle
- * @shm_path: shared memory files path
+ * @stream_fds: stream file descriptors.
  *
  * Returns channel pointer if successful, %NULL otherwise.
  *
@@ -215,18 +221,23 @@ int channel_backend_init(struct channel_backend *chanb,
 			 const struct lttng_ust_lib_ring_buffer_config *config,
 			 size_t subbuf_size, size_t num_subbuf,
 			 struct lttng_ust_shm_handle *handle,
-			 const char *shm_path)
+			 const int *stream_fds)
 {
 	struct channel *chan = caa_container_of(chanb, struct channel, backend);
 	unsigned int i;
 	int ret;
 	size_t shmsize = 0, num_subbuf_alloc;
+	long page_size;
 
 	if (!name)
 		return -EPERM;
 
+	page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size <= 0) {
+		return -ENOMEM;
+	}
 	/* Check that the subbuffer size is larger than a page. */
-	if (subbuf_size < PAGE_SIZE)
+	if (subbuf_size < page_size)
 		return -EINVAL;
 
 	/*
@@ -269,7 +280,7 @@ int channel_backend_init(struct channel_backend *chanb,
 	num_subbuf_alloc = num_subbuf + 1;
 	shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
 	shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc;
-	shmsize += offset_align(shmsize, PAGE_SIZE);
+	shmsize += offset_align(shmsize, page_size);
 	shmsize += subbuf_size * num_subbuf_alloc;
 	shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages));
 	shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages) * num_subbuf_alloc;
@@ -288,21 +299,9 @@ int channel_backend_init(struct channel_backend *chanb,
 		 */
 		for_each_possible_cpu(i) {
 			struct shm_object *shmobj;
-			char shm_buf_path[PATH_MAX];
-
-			if (shm_path) {
-				char cpu_nr[UINT_MAX_STR_LEN];	/* unsigned int max len */
-
-				strncpy(shm_buf_path, shm_path, PATH_MAX);
-				shm_buf_path[PATH_MAX - 1] = '\0';
-				ret = snprintf(cpu_nr, UINT_MAX_STR_LEN, "%u", i);
-				if (ret != 1)
-					goto end;
-				strncat(shm_buf_path, cpu_nr,
-					PATH_MAX - strlen(shm_buf_path) - 1);
-			}
+
 			shmobj = shm_object_table_alloc(handle->table, shmsize,
-					SHM_OBJECT_SHM, shm_path ? shm_buf_path : NULL);
+					SHM_OBJECT_SHM, stream_fds[i]);
 			if (!shmobj)
 				goto end;
 			align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -321,7 +320,7 @@ int channel_backend_init(struct channel_backend *chanb,
 		struct lttng_ust_lib_ring_buffer *buf;
 
 		shmobj = shm_object_table_alloc(handle->table, shmsize,
-					SHM_OBJECT_SHM, shm_path);
+					SHM_OBJECT_SHM, stream_fds[0]);
 		if (!shmobj)
 			goto end;
 		align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));