[PATCH 4/4] ceph: add IO size metrics support

[xiubli@redhat.com]

From: Xiubo Li <xiubli@redhat.com>

This will collect IO's total size and then calculate the average
size, and also will collect the min/max IO sizes.

The debugfs will show the size metrics in byte and will let the
userspace applications to switch to what they need.

URL: https://tracker.ceph.com/issues/49913
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 fs/ceph/addr.c    | 14 ++++++++------
 fs/ceph/debugfs.c | 37 +++++++++++++++++++++++++++++++++----
 fs/ceph/file.c    | 23 +++++++++++------------
 fs/ceph/metric.c  | 44 ++++++++++++++++++++++++++++++++++++++++++--
 fs/ceph/metric.h  | 10 ++++++++--
 5 files changed, 102 insertions(+), 26 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 7c2802758d0e..d8a3624bc81d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -227,7 +227,7 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 	int err = req->r_result;
 
 	ceph_update_read_metrics(&fsc->mdsc->metric, req->r_start_latency,
-				 req->r_end_latency, err);
+				 req->r_end_latency, osd_data->length, err);
 
 	dout("%s: result %d subreq->len=%zu i_size=%lld\n", __func__, req->r_result,
 	     subreq->len, i_size_read(req->r_inode));
@@ -561,7 +561,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 		err = ceph_osdc_wait_request(osdc, req);
 
 	ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
-				  req->r_end_latency, err);
+				  req->r_end_latency, len, err);
 
 	ceph_osdc_put_request(req);
 	if (err == 0)
@@ -636,6 +636,7 @@ static void writepages_finish(struct ceph_osd_request *req)
 	struct ceph_snap_context *snapc = req->r_snapc;
 	struct address_space *mapping = inode->i_mapping;
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+	unsigned int len = 0;
 	bool remove_page;
 
 	dout("writepages_finish %p rc %d\n", inode, rc);
@@ -648,9 +649,6 @@ static void writepages_finish(struct ceph_osd_request *req)
 		ceph_clear_error_write(ci);
 	}
 
-	ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
-				  req->r_end_latency, rc);
-
 	/*
 	 * We lost the cache cap, need to truncate the page before
 	 * it is unlocked, otherwise we'd truncate it later in the
@@ -667,6 +665,7 @@ static void writepages_finish(struct ceph_osd_request *req)
 
 		osd_data = osd_req_op_extent_osd_data(req, i);
 		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
+		len += osd_data->length;
 		num_pages = calc_pages_for((u64)osd_data->alignment,
 					   (u64)osd_data->length);
 		total_pages += num_pages;
@@ -699,6 +698,9 @@ static void writepages_finish(struct ceph_osd_request *req)
 		release_pages(osd_data->pages, num_pages);
 	}
 
+	ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
+				  req->r_end_latency, len, rc);
+
 	ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
 
 	osd_data = osd_req_op_extent_osd_data(req, 0);
@@ -1720,7 +1722,7 @@ int ceph_uninline_data(struct file *filp, struct page *locked_page)
 		err = ceph_osdc_wait_request(&fsc->client->osdc, req);
 
 	ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
-				  req->r_end_latency, err);
+				  req->r_end_latency, len, err);
 
 out_put:
 	ceph_osdc_put_request(req);
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index 425f3356332a..38b78b45811f 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -127,7 +127,7 @@ static int mdsc_show(struct seq_file *s, void *p)
 	return 0;
 }
 
-#define CEPH_METRIC_SHOW(name, total, avg, min, max, sq) {		\
+#define CEPH_LAT_METRIC_SHOW(name, total, avg, min, max, sq) {		\
 	s64 _total, _avg, _min, _max, _sq, _st;				\
 	_avg = ktime_to_us(avg);					\
 	_min = ktime_to_us(min == KTIME_MAX ? 0 : min);			\
@@ -140,6 +140,12 @@ static int mdsc_show(struct seq_file *s, void *p)
 		   name, total, _avg, _min, _max, _st);			\
 }
 
+#define CEPH_SZ_METRIC_SHOW(name, total, avg, min, max, sum) {		\
+	u64 _min = min == U64_MAX ? 0 : min;				\
+	seq_printf(s, "%-14s%-12lld%-16llu%-16llu%-16llu%llu\n",	\
+		   name, total, avg, _min, max, sum);			\
+}
+
 static int metric_show(struct seq_file *s, void *p)
 {
 	struct ceph_fs_client *fsc = s->private;
@@ -147,6 +153,7 @@ static int metric_show(struct seq_file *s, void *p)
 	struct ceph_client_metric *m = &mdsc->metric;
 	int nr_caps = 0;
 	s64 total, sum, avg, min, max, sq;
+	u64 sum_sz, avg_sz, min_sz, max_sz;
 
 	sum = percpu_counter_sum(&m->total_inodes);
 	seq_printf(s, "item                               total\n");
@@ -170,7 +177,7 @@ static int metric_show(struct seq_file *s, void *p)
 	max = m->read_latency_max;
 	sq = m->read_latency_sq_sum;
 	spin_unlock(&m->read_metric_lock);
-	CEPH_METRIC_SHOW("read", total, avg, min, max, sq);
+	CEPH_LAT_METRIC_SHOW("read", total, avg, min, max, sq);
 
 	spin_lock(&m->write_metric_lock);
 	total = m->total_writes;
@@ -180,7 +187,7 @@ static int metric_show(struct seq_file *s, void *p)
 	max = m->write_latency_max;
 	sq = m->write_latency_sq_sum;
 	spin_unlock(&m->write_metric_lock);
-	CEPH_METRIC_SHOW("write", total, avg, min, max, sq);
+	CEPH_LAT_METRIC_SHOW("write", total, avg, min, max, sq);
 
 	spin_lock(&m->metadata_metric_lock);
 	total = m->total_metadatas;
@@ -190,7 +197,29 @@ static int metric_show(struct seq_file *s, void *p)
 	max = m->metadata_latency_max;
 	sq = m->metadata_latency_sq_sum;
 	spin_unlock(&m->metadata_metric_lock);
-	CEPH_METRIC_SHOW("metadata", total, avg, min, max, sq);
+	CEPH_LAT_METRIC_SHOW("metadata", total, avg, min, max, sq);
+
+	seq_printf(s, "\n");
+	seq_printf(s, "item          total       avg_sz(bytes)   min_sz(bytes)   max_sz(bytes)  total_sz(bytes)\n");
+	seq_printf(s, "----------------------------------------------------------------------------------------\n");
+
+	spin_lock(&m->read_metric_lock);
+	total = m->total_reads;
+	sum_sz = m->read_size_sum;
+	avg_sz = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum_sz, total) : 0;
+	min_sz = m->read_size_min;
+	max_sz = m->read_size_max;
+	spin_unlock(&m->read_metric_lock);
+	CEPH_SZ_METRIC_SHOW("read", total, avg_sz, min_sz, max_sz, sum_sz);
+
+	spin_lock(&m->write_metric_lock);
+	total = m->total_writes;
+	sum_sz = m->write_size_sum;
+	avg_sz = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum_sz, total) : 0;
+	min_sz = m->write_size_min;
+	max_sz = m->write_size_max;
+	spin_unlock(&m->write_metric_lock);
+	CEPH_SZ_METRIC_SHOW("write", total, avg_sz, min_sz, max_sz, sum_sz);
 
 	seq_printf(s, "\n");
 	seq_printf(s, "item          total           miss            hit\n");
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 31542eac7e59..db43d2d013b9 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -898,7 +898,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
 		ceph_update_read_metrics(&fsc->mdsc->metric,
 					 req->r_start_latency,
 					 req->r_end_latency,
-					 ret);
+					 len, ret);
 
 		ceph_osdc_put_request(req);
 
@@ -1030,12 +1030,12 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 	struct ceph_aio_request *aio_req = req->r_priv;
 	struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
 	struct ceph_client_metric *metric = &ceph_sb_to_mdsc(inode->i_sb)->metric;
+	unsigned int len = osd_data->bvec_pos.iter.bi_size;
 
 	BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_BVECS);
 	BUG_ON(!osd_data->num_bvecs);
 
-	dout("ceph_aio_complete_req %p rc %d bytes %u\n",
-	     inode, rc, osd_data->bvec_pos.iter.bi_size);
+	dout("ceph_aio_complete_req %p rc %d bytes %u\n", inode, rc, len);
 
 	if (rc == -EOLDSNAPC) {
 		struct ceph_aio_work *aio_work;
@@ -1053,9 +1053,9 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 	} else if (!aio_req->write) {
 		if (rc == -ENOENT)
 			rc = 0;
-		if (rc >= 0 && osd_data->bvec_pos.iter.bi_size > rc) {
+		if (rc >= 0 && len > rc) {
 			struct iov_iter i;
-			int zlen = osd_data->bvec_pos.iter.bi_size - rc;
+			int zlen = len - rc;
 
 			/*
 			 * If read is satisfied by single OSD request,
@@ -1072,8 +1072,7 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 			}
 
 			iov_iter_bvec(&i, READ, osd_data->bvec_pos.bvecs,
-				      osd_data->num_bvecs,
-				      osd_data->bvec_pos.iter.bi_size);
+				      osd_data->num_bvecs, len);
 			iov_iter_advance(&i, rc);
 			iov_iter_zero(zlen, &i);
 		}
@@ -1083,10 +1082,10 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 	if (req->r_start_latency) {
 		if (aio_req->write)
 			ceph_update_write_metrics(metric, req->r_start_latency,
-						  req->r_end_latency, rc);
+						  req->r_end_latency, len, rc);
 		else
 			ceph_update_read_metrics(metric, req->r_start_latency,
-						 req->r_end_latency, rc);
+						 req->r_end_latency, len, rc);
 	}
 
 	put_bvecs(osd_data->bvec_pos.bvecs, osd_data->num_bvecs,
@@ -1294,10 +1293,10 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 
 		if (write)
 			ceph_update_write_metrics(metric, req->r_start_latency,
-						  req->r_end_latency, ret);
+						  req->r_end_latency, len, ret);
 		else
 			ceph_update_read_metrics(metric, req->r_start_latency,
-						 req->r_end_latency, ret);
+						 req->r_end_latency, len, ret);
 
 		size = i_size_read(inode);
 		if (!write) {
@@ -1471,7 +1470,7 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
 			ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
 
 		ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
-					  req->r_end_latency, ret);
+					  req->r_end_latency, len, ret);
 out:
 		ceph_osdc_put_request(req);
 		if (ret != 0) {
diff --git a/fs/ceph/metric.c b/fs/ceph/metric.c
index d5560ff99a9d..ff3c9d5cf9ff 100644
--- a/fs/ceph/metric.c
+++ b/fs/ceph/metric.c
@@ -189,6 +189,9 @@ int ceph_metric_init(struct ceph_client_metric *m)
 	m->read_latency_max = 0;
 	m->total_reads = 0;
 	m->read_latency_sum = 0;
+	m->read_size_min = U64_MAX;
+	m->read_size_max = 0;
+	m->read_size_sum = 0;
 
 	spin_lock_init(&m->write_metric_lock);
 	m->write_latency_sq_sum = 0;
@@ -196,6 +199,9 @@ int ceph_metric_init(struct ceph_client_metric *m)
 	m->write_latency_max = 0;
 	m->total_writes = 0;
 	m->write_latency_sum = 0;
+	m->write_size_min = U64_MAX;
+	m->write_size_max = 0;
+	m->write_size_sum = 0;
 
 	spin_lock_init(&m->metadata_metric_lock);
 	m->metadata_latency_sq_sum = 0;
@@ -306,9 +312,41 @@ static inline void __update_latency(struct ceph_client_metric *m,
 	*sq_sump += sq;
 }
 
+static inline void __update_size(struct ceph_client_metric *m,
+				 metric_type type, unsigned int size)
+{
+	ktime_t total;
+	u64 *minp, *maxp, *sump;
+
+	switch (type) {
+	case CEPH_METRIC_READ:
+		total = m->total_reads;
+		sump = &m->read_size_sum;
+		minp = &m->read_size_min;
+		maxp = &m->read_size_max;
+		break;
+	case CEPH_METRIC_WRITE:
+		total = m->total_writes;
+		sump = &m->write_size_sum;
+		minp = &m->write_size_min;
+		maxp = &m->write_size_max;
+		break;
+	case CEPH_METRIC_METADATA:
+	default:
+		return;
+	}
+
+	*sump += size;
+
+	if (unlikely(size < *minp))
+		*minp = size;
+	if (unlikely(size > *maxp))
+		*maxp = size;
+}
+
 void ceph_update_read_metrics(struct ceph_client_metric *m,
 			      ktime_t r_start, ktime_t r_end,
-			      int rc)
+			      unsigned int size, int rc)
 {
 	ktime_t lat = ktime_sub(r_end, r_start);
 
@@ -317,12 +355,13 @@ void ceph_update_read_metrics(struct ceph_client_metric *m,
 
 	spin_lock(&m->read_metric_lock);
 	__update_latency(m, CEPH_METRIC_READ, lat);
+	__update_size(m, CEPH_METRIC_READ, size);
 	spin_unlock(&m->read_metric_lock);
 }
 
 void ceph_update_write_metrics(struct ceph_client_metric *m,
 			       ktime_t r_start, ktime_t r_end,
-			       int rc)
+			       unsigned int size, int rc)
 {
 	ktime_t lat = ktime_sub(r_end, r_start);
 
@@ -331,6 +370,7 @@ void ceph_update_write_metrics(struct ceph_client_metric *m,
 
 	spin_lock(&m->write_metric_lock);
 	__update_latency(m, CEPH_METRIC_WRITE, lat);
+	__update_size(m, CEPH_METRIC_WRITE, size);
 	spin_unlock(&m->write_metric_lock);
 }
 
diff --git a/fs/ceph/metric.h b/fs/ceph/metric.h
index 57b5f0ec38be..64651b6ac886 100644
--- a/fs/ceph/metric.h
+++ b/fs/ceph/metric.h
@@ -110,6 +110,9 @@ struct ceph_client_metric {
 
 	spinlock_t read_metric_lock;
 	u64 total_reads;
+	u64 read_size_sum;
+	u64 read_size_min;
+	u64 read_size_max;
 	ktime_t read_latency_sum;
 	ktime_t read_latency_sq_sum;
 	ktime_t read_latency_min;
@@ -117,6 +120,9 @@ struct ceph_client_metric {
 
 	spinlock_t write_metric_lock;
 	u64 total_writes;
+	u64 write_size_sum;
+	u64 write_size_min;
+	u64 write_size_max;
 	ktime_t write_latency_sum;
 	ktime_t write_latency_sq_sum;
 	ktime_t write_latency_min;
@@ -164,10 +170,10 @@ static inline void ceph_update_cap_mis(struct ceph_client_metric *m)
 
 extern void ceph_update_read_metrics(struct ceph_client_metric *m,
 				     ktime_t r_start, ktime_t r_end,
-				     int rc);
+				     unsigned int size, int rc);
 extern void ceph_update_write_metrics(struct ceph_client_metric *m,
 				      ktime_t r_start, ktime_t r_end,
-				      int rc);
+				      unsigned int size, int rc);
 extern void ceph_update_metadata_metrics(struct ceph_client_metric *m,
 				         ktime_t r_start, ktime_t r_end,
 					 int rc);
-- 
2.27.0