kyber: add debugfs attributes

Expose the domain token pools, asynchronous sbitmap depth, domain
request lists, and batching state.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 134 insertions, 1 deletions

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index a3b887109310..8ec738f872e5 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -267,7 +267,7 @@ static const char *const rqf_name[] = {
 };
 #undef RQF_NAME
 
-static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
+int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 {
         struct request *rq = list_entry_rq(v);
         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
@@ -291,6 +291,7 @@ static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
         seq_puts(m, "}\n");
         return 0;
 }
+EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 
 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
         __acquires(&hctx->lock)
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index a5ac21c81ea3..dd3bbfe74f46 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -14,6 +14,8 @@ struct blk_mq_debugfs_attr {
         const struct seq_operations *seq_ops;
 };
 
+int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);
+
 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,
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 3b0090bc5dd1..b9faabc75fdb 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -26,6 +26,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-mq-tag.h"
 #include "blk-stat.h"
@@ -683,6 +684,131 @@ static struct elv_fs_entry kyber_sched_attrs[] = {
 };
 #undef KYBER_LAT_ATTR
 
+#ifdef CONFIG_BLK_DEBUG_FS
+#define KYBER_DEBUGFS_DOMAIN_ATTRS(domain, name)                        \
+static int kyber_##name##_tokens_show(void *data, struct seq_file *m)   \
+{                                                                       \
+        struct request_queue *q = data;                                 \
+        struct kyber_queue_data *kqd = q->elevator->elevator_data;      \
+                                                                        \
+        sbitmap_queue_show(&kqd->domain_tokens[domain], m);             \
+        return 0;                                                       \
+}                                                                       \
+                                                                        \
+static void *kyber_##name##_rqs_start(struct seq_file *m, loff_t *pos)  \
+        __acquires(&khd->lock)                                          \
+{                                                                       \
+        struct blk_mq_hw_ctx *hctx = m->private;                        \
+        struct kyber_hctx_data *khd = hctx->sched_data;                 \
+                                                                        \
+        spin_lock(&khd->lock);                                          \
+        return seq_list_start(&khd->rqs[domain], *pos);                 \
+}                                                                       \
+                                                                        \
+static void *kyber_##name##_rqs_next(struct seq_file *m, void *v,       \
+                                     loff_t *pos)                       \
+{                                                                       \
+        struct blk_mq_hw_ctx *hctx = m->private;                        \
+        struct kyber_hctx_data *khd = hctx->sched_data;                 \
+                                                                        \
+        return seq_list_next(v, &khd->rqs[domain], pos);                \
+}                                                                       \
+                                                                        \
+static void kyber_##name##_rqs_stop(struct seq_file *m, void *v)        \
+        __releases(&khd->lock)                                          \
+{                                                                       \
+        struct blk_mq_hw_ctx *hctx = m->private;                        \
+        struct kyber_hctx_data *khd = hctx->sched_data;                 \
+                                                                        \
+        spin_unlock(&khd->lock);                                        \
+}                                                                       \
+                                                                        \
+static const struct seq_operations kyber_##name##_rqs_seq_ops = {       \
+        .start  = kyber_##name##_rqs_start,                             \
+        .next   = kyber_##name##_rqs_next,                              \
+        .stop   = kyber_##name##_rqs_stop,                              \
+        .show   = blk_mq_debugfs_rq_show,                               \
+};                                                                      \
+                                                                        \
+static int kyber_##name##_waiting_show(void *data, struct seq_file *m)  \
+{                                                                       \
+        struct blk_mq_hw_ctx *hctx = data;                              \
+        struct kyber_hctx_data *khd = hctx->sched_data;                 \
+        wait_queue_t *wait = &khd->domain_wait[domain];                 \
+                                                                        \
+        seq_printf(m, "%d\n", !list_empty_careful(&wait->task_list));   \
+        return 0;                                                       \
+}
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_READ, read)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_SYNC_WRITE, sync_write)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_OTHER, other)
+#undef KYBER_DEBUGFS_DOMAIN_ATTRS
+
+static int kyber_async_depth_show(void *data, struct seq_file *m)
+{
+        struct request_queue *q = data;
+        struct kyber_queue_data *kqd = q->elevator->elevator_data;
+
+        seq_printf(m, "%u\n", kqd->async_depth);
+        return 0;
+}
+
+static int kyber_cur_domain_show(void *data, struct seq_file *m)
+{
+        struct blk_mq_hw_ctx *hctx = data;
+        struct kyber_hctx_data *khd = hctx->sched_data;
+
+        switch (khd->cur_domain) {
+        case KYBER_READ:
+                seq_puts(m, "READ\n");
+                break;
+        case KYBER_SYNC_WRITE:
+                seq_puts(m, "SYNC_WRITE\n");
+                break;
+        case KYBER_OTHER:
+                seq_puts(m, "OTHER\n");
+                break;
+        default:
+                seq_printf(m, "%u\n", khd->cur_domain);
+                break;
+        }
+        return 0;
+}
+
+static int kyber_batching_show(void *data, struct seq_file *m)
+{
+        struct blk_mq_hw_ctx *hctx = data;
+        struct kyber_hctx_data *khd = hctx->sched_data;
+
+        seq_printf(m, "%u\n", khd->batching);
+        return 0;
+}
+
+#define KYBER_QUEUE_DOMAIN_ATTRS(name)  \
+        {#name "_tokens", 0400, kyber_##name##_tokens_show}
+static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = {
+        KYBER_QUEUE_DOMAIN_ATTRS(read),
+        KYBER_QUEUE_DOMAIN_ATTRS(sync_write),
+        KYBER_QUEUE_DOMAIN_ATTRS(other),
+        {"async_depth", 0400, kyber_async_depth_show},
+        {},
+};
+#undef KYBER_QUEUE_DOMAIN_ATTRS
+
+#define KYBER_HCTX_DOMAIN_ATTRS(name)                                   \
+        {#name "_rqs", 0400, .seq_ops = &kyber_##name##_rqs_seq_ops},   \
+        {#name "_waiting", 0400, kyber_##name##_waiting_show}
+static const struct blk_mq_debugfs_attr kyber_hctx_debugfs_attrs[] = {
+        KYBER_HCTX_DOMAIN_ATTRS(read),
+        KYBER_HCTX_DOMAIN_ATTRS(sync_write),
+        KYBER_HCTX_DOMAIN_ATTRS(other),
+        {"cur_domain", 0400, kyber_cur_domain_show},
+        {"batching", 0400, kyber_batching_show},
+        {},
+};
+#undef KYBER_HCTX_DOMAIN_ATTRS
+#endif
+
 static struct elevator_type kyber_sched = {
         .ops.mq = {
                 .init_sched = kyber_init_sched,
@@ -696,6 +822,10 @@ static struct elevator_type kyber_sched = {
                 .has_work = kyber_has_work,
         },
         .uses_mq = true,
+#ifdef CONFIG_BLK_DEBUG_FS
+        .queue_debugfs_attrs = kyber_queue_debugfs_attrs,
+        .hctx_debugfs_attrs = kyber_hctx_debugfs_attrs,
+#endif
         .elevator_attrs = kyber_sched_attrs,
         .elevator_name = "kyber",
         .elevator_owner = THIS_MODULE,