blk-mq-debugfs: allow schedulers to register debugfs attributes
This provides the infrastructure for schedulers to expose their internal
state through debugfs. We add a list of queue attributes and a list of
hctx attributes to struct elevator_type and wire them up when switching
schedulers.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Add missing seq_file.h header in blk-mq-debugfs.h
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 260cf76..a3b8871 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -24,15 +24,6 @@
#include "blk-mq-debugfs.h"
#include "blk-mq-tag.h"
-struct blk_mq_debugfs_attr {
- const char *name;
- umode_t mode;
- int (*show)(void *, struct seq_file *);
- ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
- /* Set either .show or .seq_ops. */
- const struct seq_operations *seq_ops;
-};
-
static int blk_flags_show(struct seq_file *m, const unsigned long flags,
const char *const *flag_name, int flag_name_count)
{
@@ -725,6 +716,9 @@ int blk_mq_debugfs_register(struct request_queue *q)
queue_for_each_hw_ctx(q, hctx, i) {
if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
goto err;
+ if (q->elevator && !hctx->sched_debugfs_dir &&
+ blk_mq_debugfs_register_sched_hctx(q, hctx))
+ goto err;
}
return 0;
@@ -737,6 +731,7 @@ int blk_mq_debugfs_register(struct request_queue *q)
void blk_mq_debugfs_unregister(struct request_queue *q)
{
debugfs_remove_recursive(q->debugfs_dir);
+ q->sched_debugfs_dir = NULL;
q->debugfs_dir = NULL;
}
@@ -791,6 +786,7 @@ int blk_mq_debugfs_register_hctx(struct request_queue *q,
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
debugfs_remove_recursive(hctx->debugfs_dir);
+ hctx->sched_debugfs_dir = NULL;
hctx->debugfs_dir = NULL;
}
@@ -815,3 +811,63 @@ void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
queue_for_each_hw_ctx(q, hctx, i)
blk_mq_debugfs_unregister_hctx(hctx);
}
+
+int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+ struct elevator_type *e = q->elevator->type;
+
+ if (!q->debugfs_dir)
+ return -ENOENT;
+
+ if (!e->queue_debugfs_attrs)
+ return 0;
+
+ q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
+ if (!q->sched_debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(q->sched_debugfs_dir, q,
+ e->queue_debugfs_attrs))
+ goto err;
+
+ return 0;
+
+err:
+ blk_mq_debugfs_unregister_sched(q);
+ return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+ debugfs_remove_recursive(q->sched_debugfs_dir);
+ q->sched_debugfs_dir = NULL;
+}
+
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ struct elevator_type *e = q->elevator->type;
+
+ if (!hctx->debugfs_dir)
+ return -ENOENT;
+
+ if (!e->hctx_debugfs_attrs)
+ return 0;
+
+ hctx->sched_debugfs_dir = debugfs_create_dir("sched",
+ hctx->debugfs_dir);
+ if (!hctx->sched_debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
+ e->hctx_debugfs_attrs))
+ return -ENOMEM;
+
+ return 0;
+}
+
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ debugfs_remove_recursive(hctx->sched_debugfs_dir);
+ hctx->sched_debugfs_dir = NULL;
+}
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index 596e9b1..a5ac21c8 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -2,6 +2,18 @@
#define INT_BLK_MQ_DEBUGFS_H
#ifdef CONFIG_BLK_DEBUG_FS
+
+#include <linux/seq_file.h>
+
+struct blk_mq_debugfs_attr {
+ const char *name;
+ umode_t mode;
+ int (*show)(void *, struct seq_file *);
+ ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
+ /* Set either .show or .seq_ops. */
+ const struct seq_operations *seq_ops;
+};
+
int blk_mq_debugfs_register(struct request_queue *q);
void blk_mq_debugfs_unregister(struct request_queue *q);
int blk_mq_debugfs_register_hctx(struct request_queue *q,
@@ -9,6 +21,12 @@ int blk_mq_debugfs_register_hctx(struct request_queue *q,
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
int blk_mq_debugfs_register_hctxs(struct request_queue *q);
void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
+
+int blk_mq_debugfs_register_sched(struct request_queue *q);
+void blk_mq_debugfs_unregister_sched(struct request_queue *q);
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
#else
static inline int blk_mq_debugfs_register(struct request_queue *q)
{
@@ -37,6 +55,25 @@ static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
{
}
+
+static inline int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
#endif
#endif
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e79e9f1..1f5b692 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -11,6 +11,7 @@
#include "blk.h"
#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
#include "blk-mq-sched.h"
#include "blk-mq-tag.h"
#include "blk-wbt.h"
@@ -472,6 +473,8 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
}
}
+ blk_mq_debugfs_register_sched_hctx(q, hctx);
+
return 0;
}
@@ -483,6 +486,8 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
if (!e)
return;
+ blk_mq_debugfs_unregister_sched_hctx(hctx);
+
if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
e->type->ops.mq.exit_hctx(hctx, hctx_idx);
hctx->sched_data = NULL;
@@ -519,8 +524,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
if (ret)
goto err;
- if (e->ops.mq.init_hctx) {
- queue_for_each_hw_ctx(q, hctx, i) {
+ blk_mq_debugfs_register_sched(q);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (e->ops.mq.init_hctx) {
ret = e->ops.mq.init_hctx(hctx, i);
if (ret) {
eq = q->elevator;
@@ -529,6 +536,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
return ret;
}
}
+ blk_mq_debugfs_register_sched_hctx(q, hctx);
}
return 0;
@@ -544,14 +552,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
struct blk_mq_hw_ctx *hctx;
unsigned int i;
- if (e->type->ops.mq.exit_hctx) {
- queue_for_each_hw_ctx(q, hctx, i) {
- if (hctx->sched_data) {
- e->type->ops.mq.exit_hctx(hctx, i);
- hctx->sched_data = NULL;
- }
+ queue_for_each_hw_ctx(q, hctx, i) {
+ blk_mq_debugfs_unregister_sched_hctx(hctx);
+ if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+ e->type->ops.mq.exit_hctx(hctx, i);
+ hctx->sched_data = NULL;
}
}
+ blk_mq_debugfs_unregister_sched(q);
if (e->type->ops.mq.exit_sched)
e->type->ops.mq.exit_sched(e);
blk_mq_sched_tags_teardown(q);