From d332ce091813d11a46144354baa72b755833392f Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Thu, 4 May 2017 08:24:40 -0600 Subject: [PATCH] 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 Reviewed-by: Hannes Reinecke Add missing seq_file.h header in blk-mq-debugfs.h Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 74 +++++++++++++++++++++++++++++++++++----- block/blk-mq-debugfs.h | 37 ++++++++++++++++++++ block/blk-mq-sched.c | 24 ++++++++----- include/linux/blk-mq.h | 1 + include/linux/blkdev.h | 1 + include/linux/elevator.h | 7 ++++ 6 files changed, 127 insertions(+), 17 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 260cf76e0705..a3b887109310 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 @@ err: 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 @@ err: 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 596e9b16d3d1..a5ac21c81ea3 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 + +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 e79e9f18d7c2..1f5b692526ae 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); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index de8ed9aaa156..c47aa248c640 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -60,6 +60,7 @@ struct blk_mq_hw_ctx { #ifdef CONFIG_BLK_DEBUG_FS struct dentry *debugfs_dir; + struct dentry *sched_debugfs_dir; #endif }; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b49a79a29e58..80ae958717a1 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -579,6 +579,7 @@ struct request_queue { #ifdef CONFIG_BLK_DEBUG_FS struct dentry *debugfs_dir; + struct dentry *sched_debugfs_dir; #endif bool mq_sysfs_init_done; diff --git a/include/linux/elevator.h b/include/linux/elevator.h index d44840368ee7..9ec5e22846e0 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -8,6 +8,9 @@ struct io_cq; struct elevator_type; +#ifdef CONFIG_BLK_DEBUG_FS +struct blk_mq_debugfs_attr; +#endif /* * Return values from elevator merger @@ -144,6 +147,10 @@ struct elevator_type char elevator_name[ELV_NAME_MAX]; struct module *elevator_owner; bool uses_mq; +#ifdef CONFIG_BLK_DEBUG_FS + const struct blk_mq_debugfs_attr *queue_debugfs_attrs; + const struct blk_mq_debugfs_attr *hctx_debugfs_attrs; +#endif /* managed by elevator core */ char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */