Commit 950cd7e9 authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

blk-mq: move hctx->dispatch and ctx->rq_list from sysfs to debugfs 



These lists are only useful for debugging; they definitely don't belong
in sysfs. Putting them in debugfs also removes the limitation of a
single page of output.

Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 9abb2ad2

block/blk-mq-debugfs.c

+106 −0
Original line number Diff line number Diff line
@@ -29,6 +29,20 @@ struct blk_mq_debugfs_attr { 


static struct dentry *block_debugfs_root;



static int blk_mq_debugfs_seq_open(struct inode *inode, struct file *file,

				   const struct seq_operations *ops)

{

	struct seq_file *m;

	int ret;



	ret = seq_open(file, ops);

	if (!ret) {

		m = file->private_data;

		m->private = inode->i_private;

	}

	return ret;

}



static int hctx_state_show(struct seq_file *m, void *v)

{

	struct blk_mq_hw_ctx *hctx = m->private;
@@ -69,12 +83,104 @@ static const struct file_operations hctx_flags_fops = { 
	.release	= single_release,

};



static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)

{

	struct request *rq = list_entry_rq(v);



	seq_printf(m, "%p\n", rq);

	return 0;

}



static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)

{

	struct blk_mq_hw_ctx *hctx = m->private;



	spin_lock(&hctx->lock);

	return seq_list_start(&hctx->dispatch, *pos);

}



static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)

{

	struct blk_mq_hw_ctx *hctx = m->private;



	return seq_list_next(v, &hctx->dispatch, pos);

}



static void hctx_dispatch_stop(struct seq_file *m, void *v)

{

	struct blk_mq_hw_ctx *hctx = m->private;



	spin_unlock(&hctx->lock);

}



static const struct seq_operations hctx_dispatch_seq_ops = {

	.start	= hctx_dispatch_start,

	.next	= hctx_dispatch_next,

	.stop	= hctx_dispatch_stop,

	.show	= blk_mq_debugfs_rq_show,

};



static int hctx_dispatch_open(struct inode *inode, struct file *file)

{

	return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops);

}



static const struct file_operations hctx_dispatch_fops = {

	.open		= hctx_dispatch_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= seq_release,

};



static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)

{

	struct blk_mq_ctx *ctx = m->private;



	spin_lock(&ctx->lock);

	return seq_list_start(&ctx->rq_list, *pos);

}



static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)

{

	struct blk_mq_ctx *ctx = m->private;



	return seq_list_next(v, &ctx->rq_list, pos);

}



static void ctx_rq_list_stop(struct seq_file *m, void *v)

{

	struct blk_mq_ctx *ctx = m->private;



	spin_unlock(&ctx->lock);

}



static const struct seq_operations ctx_rq_list_seq_ops = {

	.start	= ctx_rq_list_start,

	.next	= ctx_rq_list_next,

	.stop	= ctx_rq_list_stop,

	.show	= blk_mq_debugfs_rq_show,

};



static int ctx_rq_list_open(struct inode *inode, struct file *file)

{

	return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops);

}



static const struct file_operations ctx_rq_list_fops = {

	.open		= ctx_rq_list_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= seq_release,

};



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},

};



static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {

	{"rq_list", 0400, &ctx_rq_list_fops},

};



int blk_mq_debugfs_register(struct request_queue *q, const char *name)

block/blk-mq-sysfs.c

+0 −57
Original line number Diff line number Diff line
@@ -139,41 +139,6 @@ static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page) 
				ctx->rq_completed[0]);

}



static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg)

{

	struct request *rq;

	int len = snprintf(page, PAGE_SIZE - 1, "%s:\n", msg);



	list_for_each_entry(rq, list, queuelist) {

		const int rq_len = 2 * sizeof(rq) + 2;



		/* if the output will be truncated */

		if (PAGE_SIZE - 1 < len + rq_len) {

			/* backspacing if it can't hold '\t...\n' */

			if (PAGE_SIZE - 1 < len + 5)

				len -= rq_len;

			len += snprintf(page + len, PAGE_SIZE - 1 - len,

					"\t...\n");

			break;

		}

		len += snprintf(page + len, PAGE_SIZE - 1 - len,

				"\t%p\n", rq);

	}



	return len;

}



static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)

{

	ssize_t ret;



	spin_lock(&ctx->lock);

	ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending");

	spin_unlock(&ctx->lock);



	return ret;

}



static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page)

{

	return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n",
@@ -219,18 +184,6 @@ static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx, 
	return page - start_page;

}



static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,

					    char *page)

{

	ssize_t ret;



	spin_lock(&hctx->lock);

	ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");

	spin_unlock(&hctx->lock);



	return ret;

}



static ssize_t blk_mq_hw_sysfs_sched_tags_show(struct blk_mq_hw_ctx *hctx, char *page)

{

	if (hctx->sched_tags)
@@ -320,16 +273,11 @@ static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = { 
	.attr = {.name = "completed", .mode = S_IRUGO },

	.show = blk_mq_sysfs_completed_show,

};

static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {

	.attr = {.name = "rq_list", .mode = S_IRUGO },

	.show = blk_mq_sysfs_rq_list_show,

};



static struct attribute *default_ctx_attrs[] = {

	&blk_mq_sysfs_dispatched.attr,

	&blk_mq_sysfs_merged.attr,

	&blk_mq_sysfs_completed.attr,

	&blk_mq_sysfs_rq_list.attr,

	NULL,

};
@@ -349,10 +297,6 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = { 
	.attr = {.name = "active", .mode = S_IRUGO },

	.show = blk_mq_hw_sysfs_active_show,

};

static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {

	.attr = {.name = "pending", .mode = S_IRUGO },

	.show = blk_mq_hw_sysfs_rq_list_show,

};

static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_sched_tags = {

	.attr = {.name = "sched_tags", .mode = S_IRUGO },

	.show = blk_mq_hw_sysfs_sched_tags_show,
@@ -380,7 +324,6 @@ static struct attribute *default_hw_ctx_attrs[] = { 
	&blk_mq_hw_sysfs_queued.attr,

	&blk_mq_hw_sysfs_run.attr,

	&blk_mq_hw_sysfs_dispatched.attr,

	&blk_mq_hw_sysfs_pending.attr,

	&blk_mq_hw_sysfs_tags.attr,

	&blk_mq_hw_sysfs_sched_tags.attr,

	&blk_mq_hw_sysfs_cpus.attr,

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