ion: Register with show_mem notification framework

Bugs in Ion clients are semi-common cause of out of memory
errors. Register with the show_mem notification framework
to let Ion dump out data for debugging. To avoid having to
take an excessive amount of locks, keep a running total of
allocated and potentially orphaned memory.

Change-Id: I52c31459d5bf975c67adb5f3fe17033c8e01d91b
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

5 files changed, 90 insertions, 16 deletions

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 5cfa495909bc..93f626bc3dad 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -260,6 +260,7 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
 	mutex_lock(&dev->buffer_lock);
 	ion_buffer_add(dev, buffer);
 	mutex_unlock(&dev->buffer_lock);
+	atomic_add(len, &heap->total_allocated);
 	return buffer;
 
 err:
@@ -277,6 +278,7 @@ void ion_buffer_destroy(struct ion_buffer *buffer)
 		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
 	buffer->heap->ops->unmap_dma(buffer->heap, buffer);
 
+	atomic_sub(buffer->size, &buffer->heap->total_allocated);
 	buffer->heap->ops->free(buffer);
 	vfree(buffer->pages);
 	kfree(buffer);
@@ -311,6 +313,9 @@ static int ion_buffer_put(struct ion_buffer *buffer)
 static void ion_buffer_add_to_handle(struct ion_buffer *buffer)
 {
 	mutex_lock(&buffer->lock);
+	if (buffer->handle_count == 0)
+		atomic_add(buffer->size, &buffer->heap->total_handles);
+
 	buffer->handle_count++;
 	mutex_unlock(&buffer->lock);
 }
@@ -335,6 +340,7 @@ static void ion_buffer_remove_from_handle(struct ion_buffer *buffer)
 		task = current->group_leader;
 		get_task_comm(buffer->task_comm, task);
 		buffer->pid = task_pid_nr(task);
+		atomic_sub(buffer->size, &buffer->heap->total_handles);
 	}
 	mutex_unlock(&buffer->lock);
 }
@@ -1708,6 +1714,31 @@ static const struct file_operations debug_heap_fops = {
 	.release = single_release,
 };
 
+void show_ion_usage(struct ion_device *dev)
+{
+	struct ion_heap *heap;
+
+	if (!down_read_trylock(&dev->lock)) {
+		pr_err("Ion output would deadlock, can't print debug information\n");
+		return;
+	}
+
+	pr_info("%16.s %16.s %16.s\n", "Heap name", "Total heap size",
+					"Total orphaned size");
+	pr_info("---------------------------------\n");
+	plist_for_each_entry(heap, &dev->heaps, node) {
+		pr_info("%16.s 0x%16.x 0x%16.x\n",
+			heap->name, atomic_read(&heap->total_allocated),
+			atomic_read(&heap->total_allocated) -
+			atomic_read(&heap->total_handles));
+		if (heap->debug_show)
+			heap->debug_show(heap, NULL, 0);
+
+	}
+	up_write(&dev->lock);
+}
+
+#ifdef DEBUG_HEAP_SHRINKER
 static int debug_shrink_set(void *data, u64 val)
 {
 	struct ion_heap *heap = data;
diff --git a/drivers/staging/android/ion/ion_priv.h b/drivers/staging/android/ion/ion_priv.h
index d724153f9824..4fa0daa2f637 100644
--- a/drivers/staging/android/ion/ion_priv.h
+++ b/drivers/staging/android/ion/ion_priv.h
@@ -198,6 +198,8 @@ struct ion_heap {
 	struct task_struct *task;
 
 	int (*debug_show)(struct ion_heap *heap, struct seq_file *, void *);
+	atomic_t total_allocated;
+	atomic_t total_handles;
 };
 
 /**
diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index f31098f023f4..1d84df3d0c38 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -399,31 +399,57 @@ static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
 	struct ion_system_heap *sys_heap = container_of(heap,
 							struct ion_system_heap,
 							heap);
+	bool use_seq = s != NULL;
+	unsigned long uncached_total = 0;
+	unsigned long cached_total = 0;
+
 	int i;
 	for (i = 0; i < num_orders; i++) {
 		struct ion_page_pool *pool = sys_heap->uncached_pools[i];
-		seq_printf(s,
-			"%d order %u highmem pages in uncached pool = %lu total\n",
-			pool->high_count, pool->order,
-			(1 << pool->order) * PAGE_SIZE * pool->high_count);
-		seq_printf(s,
-			"%d order %u lowmem pages in uncached pool = %lu total\n",
-			pool->low_count, pool->order,
-			(1 << pool->order) * PAGE_SIZE * pool->low_count);
+		if (use_seq) {
+			seq_printf(s,
+				"%d order %u highmem pages in uncached pool = %lu total\n",
+				pool->high_count, pool->order,
+				(1 << pool->order) * PAGE_SIZE *
+					pool->high_count);
+			seq_printf(s,
+				"%d order %u lowmem pages in uncached pool = %lu total\n",
+				pool->low_count, pool->order,
+				(1 << pool->order) * PAGE_SIZE *
+					pool->low_count);
+		} else {
+			uncached_total += (1 << pool->order) * PAGE_SIZE *
+						pool->high_count;
+			uncached_total += (1 << pool->order) * PAGE_SIZE *
+						pool->low_count;
+		}
+
 	}
 
 	for (i = 0; i < num_orders; i++) {
 		struct ion_page_pool *pool = sys_heap->cached_pools[i];
-		seq_printf(s,
-			"%d order %u highmem pages in cached pool = %lu total\n",
-			pool->high_count, pool->order,
-			(1 << pool->order) * PAGE_SIZE * pool->high_count);
-		seq_printf(s,
-			"%d order %u lowmem pages in cached pool = %lu total\n",
-			pool->low_count, pool->order,
-			(1 << pool->order) * PAGE_SIZE * pool->low_count);
+		if (use_seq) {
+			seq_printf(s,
+				"%d order %u highmem pages in cached pool = %lu total\n",
+				pool->high_count, pool->order,
+				(1 << pool->order) * PAGE_SIZE * pool->high_count);
+			seq_printf(s,
+				"%d order %u lowmem pages in cached pool = %lu total\n",
+				pool->low_count, pool->order,
+				(1 << pool->order) * PAGE_SIZE *
+					pool->low_count);
+		} else {
+			cached_total += (1 << pool->order) * PAGE_SIZE *
+						pool->high_count;
+			cached_total += (1 << pool->order) * PAGE_SIZE *
+						pool->low_count;
+		}
 	}
 
+	if (!use_seq)
+		pr_info("uncached pool total = %lu cached pool total %lu\n",
+				uncached_total, cached_total);
+
 	return 0;
 }
 
diff --git a/drivers/staging/android/ion/msm/msm_ion.c b/drivers/staging/android/ion/msm/msm_ion.c
index 7330256d9fc7..46186ea07730 100644
--- a/drivers/staging/android/ion/msm/msm_ion.c
+++ b/drivers/staging/android/ion/msm/msm_ion.c
@@ -109,6 +109,17 @@ static struct ion_heap_desc ion_heap_meta[] = {
 };
 #endif
 
+static int msm_ion_lowmem_notifier(struct notifier_block *nb,
+					unsigned long action, void *data)
+{
+	show_ion_usage(idev);
+	return 0;
+}
+
+static struct notifier_block msm_ion_nb = {
+	.notifier_call = msm_ion_lowmem_notifier,
+};
+
 struct ion_client *msm_ion_client_create(const char *name)
 {
 	/*
@@ -949,6 +960,8 @@ static int msm_ion_probe(struct platform_device *pdev)
 	 * completely until Ion is setup
 	 */
 	idev = new_dev;
+
+	show_mem_notifier_register(&msm_ion_nb);
 	return 0;
 
 freeheaps:
diff --git a/drivers/staging/android/ion/msm_ion_priv.h b/drivers/staging/android/ion/msm_ion_priv.h
index a40f78023b3a..4ff76aa5cc60 100644
--- a/drivers/staging/android/ion/msm_ion_priv.h
+++ b/drivers/staging/android/ion/msm_ion_priv.h
@@ -123,4 +123,6 @@ int ion_heap_allow_handle_secure(enum ion_heap_type type);
  */
 struct sg_table *ion_create_chunked_sg_table(phys_addr_t buffer_base,
 					size_t chunk_size, size_t total_size);
+
+void show_ion_usage(struct ion_device *dev);
 #endif /* _MSM_ION_PRIV_H */