X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_backend.c;h=83a6e39b4b2df692c955c6930f04d432e4a2c88a;hb=0112cb7bc68d85c9c98b496937bde7af50f13cc6;hp=f7ed20df19869b767fd23f568c87e5831956ead2;hpb=bfe529f90b1354246b5d8a18f49e30595c612041;p=lttng-modules.git

diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c
index f7ed20df..83a6e39b 100644
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -52,7 +52,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	unsigned long subbuf_size, mmap_offset = 0;
 	unsigned long num_subbuf_alloc;
 	struct page **pages;
-	void **virt;
 	unsigned long i;
 
 	num_pages = size >> PAGE_SHIFT;
@@ -71,12 +70,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	if (unlikely(!pages))
 		goto pages_error;
 
-	virt = kmalloc_node(ALIGN(sizeof(*virt) * num_pages,
-				  1 << INTERNODE_CACHE_SHIFT),
-			GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
-	if (unlikely(!virt))
-		goto virt_error;
-
 	bufb->array = kmalloc_node(ALIGN(sizeof(*bufb->array)
 					 * num_subbuf_alloc,
 				  1 << INTERNODE_CACHE_SHIFT),
@@ -89,7 +82,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 					    GFP_KERNEL | __GFP_ZERO, 0);
 		if (unlikely(!pages[i]))
 			goto depopulate;
-		virt[i] = page_address(pages[i]);
 	}
 	bufb->num_pages_per_subbuf = num_pages_per_subbuf;
 
@@ -125,12 +117,21 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	else
 		bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
 
+	/* Allocate subbuffer packet counter table */
+	bufb->buf_cnt = kzalloc_node(ALIGN(
+				sizeof(struct lib_ring_buffer_backend_counts)
+				* num_subbuf,
+				1 << INTERNODE_CACHE_SHIFT),
+			GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+	if (unlikely(!bufb->buf_cnt))
+		goto free_wsb;
+
 	/* Assign pages to page index */
 	for (i = 0; i < num_subbuf_alloc; i++) {
 		for (j = 0; j < num_pages_per_subbuf; j++) {
 			CHAN_WARN_ON(chanb, page_idx > num_pages);
-			bufb->array[i]->p[j].virt = virt[page_idx];
-			bufb->array[i]->p[j].page = pages[page_idx];
+			bufb->array[i]->p[j].virt = page_address(pages[page_idx]);
+			bufb->array[i]->p[j].pfn = page_to_pfn(pages[page_idx]);
 			page_idx++;
 		}
 		if (config->output == RING_BUFFER_MMAP) {
@@ -144,10 +145,11 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	 * will not fault.
 	 */
 	wrapper_vmalloc_sync_all();
-	kfree(virt);
 	kfree(pages);
 	return 0;
 
+free_wsb:
+	kfree(bufb->buf_wsb);
 free_array:
 	for (i = 0; (i < num_subbuf_alloc && bufb->array[i]); i++)
 		kfree(bufb->array[i]);
@@ -157,8 +159,6 @@ depopulate:
 		__free_page(pages[i]);
 	kfree(bufb->array);
 array_error:
-	kfree(virt);
-virt_error:
 	kfree(pages);
 pages_error:
 	return -ENOMEM;
@@ -187,9 +187,10 @@ void lib_ring_buffer_backend_free(struct lib_ring_buffer_backend *bufb)
 		num_subbuf_alloc++;
 
 	kfree(bufb->buf_wsb);
+	kfree(bufb->buf_cnt);
 	for (i = 0; i < num_subbuf_alloc; i++) {
 		for (j = 0; j < bufb->num_pages_per_subbuf; j++)
-			__free_page(bufb->array[i]->p[j].page);
+			__free_page(pfn_to_page(bufb->array[i]->p[j].pfn));
 		kfree(bufb->array[i]);
 	}
 	kfree(bufb->array);
@@ -331,6 +332,12 @@ int channel_backend_init(struct channel_backend *chanb,
 		return -EINVAL;
 	if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
 		return -EINVAL;
+	/*
+	 * Overwrite mode buffers require at least 2 subbuffers per
+	 * buffer.
+	 */
+	if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2)
+		return -EINVAL;
 
 	ret = subbuffer_id_check_index(config, num_subbuf);
 	if (ret)
@@ -943,15 +950,15 @@ int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offse
 EXPORT_SYMBOL_GPL(lib_ring_buffer_read_cstr);
 
 /**
- * lib_ring_buffer_read_get_page - Get a whole page to read from
+ * lib_ring_buffer_read_get_pfn - Get a page frame number to read from
  * @bufb : buffer backend
  * @offset : offset within the buffer
  * @virt : pointer to page address (output)
  *
  * Should be protected by get_subbuf/put_subbuf.
- * Returns the pointer to the page struct pointer.
+ * Returns the pointer to the page frame number unsigned long.
  */
-struct page **lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb,
+unsigned long *lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb,
 					    size_t offset, void ***virt)
 {
 	size_t index;
@@ -968,9 +975,9 @@ struct page **lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb
 	CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
 		     && subbuffer_id_is_noref(config, id));
 	*virt = &rpages->p[index].virt;
-	return &rpages->p[index].page;
+	return &rpages->p[index].pfn;
 }
-EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_page);
+EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_pfn);
 
 /**
  * lib_ring_buffer_read_offset_address - get address of a buffer location