[06/10] blk-mq: export software queue pending map to debugfs

Commit Message

Omar Sandoval Jan. 23, 2017, 6:59 p.m. UTC

From: Omar Sandoval <[e-mail]>

This is useful for debugging problems where we've gotten stuck with
requests in the software queues.

Signed-off-by: Omar Sandoval <[e-mail]>
---
 block/blk-mq-debugfs.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Comments

Hannes Reinecke Jan. 24, 2017, 1:28 p.m. UTC | #1

On 01/23/2017 07:59 PM, Omar Sandoval wrote:
> From: Omar Sandoval <[e-mail]>
> 
> This is useful for debugging problems where we've gotten stuck with
> requests in the software queues.
> 
> Signed-off-by: Omar Sandoval <[e-mail]>
> ---
>  block/blk-mq-debugfs.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
Reviewed-by: Hannes Reinecke <[e-mail]>

Cheers,

Hannes

Patch

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index ee947f2f605b..4ee6ab28f56f 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -134,6 +134,20 @@  static const struct file_operations hctx_dispatch_fops = {
 	.release	= seq_release,
 };
 
+static int hctx_ctx_map_open(struct inode *inode, struct file *file)
+{
+	struct blk_mq_hw_ctx *hctx = inode->i_private;
+
+	return single_open(file, sbitmap_bitmap_show, &hctx->ctx_map);
+}
+
+static const struct file_operations hctx_ctx_map_fops = {
+	.open		= hctx_ctx_map_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 {
 	struct blk_mq_ctx *ctx = m->private;
@@ -179,6 +193,7 @@  static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 	{"state", 0400, &hctx_state_fops},
 	{"flags", 0400, &hctx_flags_fops},
 	{"dispatch", 0400, &hctx_dispatch_fops},
+	{"ctx_map", 0400, &hctx_ctx_map_fops},
 };
 
 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {