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Message-Id: <20230216112915.43036-1-frank.li@vivo.com>
Date:   Thu, 16 Feb 2023 19:29:15 +0800
From:   Yangtao Li <frank.li@...o.com>
To:     jaegeuk@...nel.org, chao@...nel.org
Cc:     linux-f2fs-devel@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org, Yangtao Li <frank.li@...o.com>
Subject: [PATCH] f2fs: add iostat latency statistics support for discard

In this patch, it adds to account discard latency.

Signed-off-by: Yangtao Li <frank.li@...o.com>
---
 fs/f2fs/data.c              |  2 +-
 fs/f2fs/f2fs.h              |  1 +
 fs/f2fs/iostat.c            | 83 +++++++++++++++++++++----------------
 fs/f2fs/iostat.h            | 49 +++++++++++-----------
 fs/f2fs/segment.c           |  8 +++-
 include/trace/events/f2fs.h | 68 ++++++++++++++++--------------
 6 files changed, 118 insertions(+), 93 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 28e09682b056..b67c0b41ee13 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2312,7 +2312,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
 			goto submit_and_realloc;
 
-		ctx = get_post_read_ctx(bio);
+		ctx = get_bio_iostat_private(bio);
 		ctx->enabled_steps |= STEP_DECOMPRESS;
 		refcount_inc(&dic->refcnt);
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 21596e0266ba..29e973f67c3c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1131,6 +1131,7 @@ enum page_type {
 	META_FLUSH,
 	IPU,		/* the below types are used by tracepoints only. */
 	OPU,
+	DISCARD,	/* used by iostat */
 };
 
 enum temp_type {
diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
index 3d5bfb1ad585..304235b4f543 100644
--- a/fs/f2fs/iostat.c
+++ b/fs/f2fs/iostat.c
@@ -86,23 +86,21 @@ int __maybe_unused iostat_info_seq_show(struct seq_file *seq, void *offset)
 
 static inline void __record_iostat_latency(struct f2fs_sb_info *sbi)
 {
-	int io, idx;
-	struct f2fs_iostat_latency iostat_lat[MAX_IO_TYPE][NR_PAGE_TYPE];
+	struct f2fs_iostat_latency iostat_lat[MAX_LAT_TYPE];
 	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
+	unsigned int lat_type;
 	unsigned long flags;
 
 	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
-	for (idx = 0; idx < MAX_IO_TYPE; idx++) {
-		for (io = 0; io < NR_PAGE_TYPE; io++) {
-			iostat_lat[idx][io].peak_lat =
-			   jiffies_to_msecs(io_lat->peak_lat[idx][io]);
-			iostat_lat[idx][io].cnt = io_lat->bio_cnt[idx][io];
-			iostat_lat[idx][io].avg_lat = iostat_lat[idx][io].cnt ?
-			   jiffies_to_msecs(io_lat->sum_lat[idx][io]) / iostat_lat[idx][io].cnt : 0;
-			io_lat->sum_lat[idx][io] = 0;
-			io_lat->peak_lat[idx][io] = 0;
-			io_lat->bio_cnt[idx][io] = 0;
-		}
+	for (lat_type = 0; lat_type < MAX_LAT_TYPE; lat_type++) {
+		iostat_lat[lat_type].peak_lat =
+		   jiffies_to_msecs(io_lat->peak_lat[lat_type]);
+		iostat_lat[lat_type].cnt = io_lat->bio_cnt[lat_type];
+		iostat_lat[lat_type].avg_lat = iostat_lat[lat_type].cnt ?
+		   jiffies_to_msecs(io_lat->sum_lat[lat_type]) / iostat_lat[lat_type].cnt : 0;
+		io_lat->sum_lat[lat_type] = 0;
+		io_lat->peak_lat[lat_type] = 0;
+		io_lat->bio_cnt[lat_type] = 0;
 	}
 	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
 
@@ -208,62 +206,75 @@ void f2fs_update_iostat(struct f2fs_sb_info *sbi, struct inode *inode,
 	f2fs_record_iostat(sbi);
 }
 
-static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
-				enum iostat_lat_type lat_type)
+static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx)
 {
-	unsigned long ts_diff;
-	unsigned int page_type = iostat_ctx->type;
 	struct f2fs_sb_info *sbi = iostat_ctx->sbi;
 	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
+	unsigned int lat_type = iostat_ctx->lat_type;
+	unsigned long ts_diff;
 	unsigned long flags;
 
 	if (!sbi->iostat_enable)
 		return;
 
-	ts_diff = jiffies - iostat_ctx->submit_ts;
-	if (page_type == META_FLUSH) {
-		page_type = META;
-	} else if (page_type >= NR_PAGE_TYPE) {
-		f2fs_warn(sbi, "%s: %d over NR_PAGE_TYPE", __func__, page_type);
+	if (lat_type >= MAX_LAT_TYPE) {
+		f2fs_warn(sbi, "%s: %d over MAX_LAT_TYPE", __func__, lat_type);
 		return;
 	}
+	ts_diff = jiffies - iostat_ctx->submit_ts;
 
 	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
-	io_lat->sum_lat[lat_type][page_type] += ts_diff;
-	io_lat->bio_cnt[lat_type][page_type]++;
-	if (ts_diff > io_lat->peak_lat[lat_type][page_type])
-		io_lat->peak_lat[lat_type][page_type] = ts_diff;
+	io_lat->sum_lat[lat_type] += ts_diff;
+	io_lat->bio_cnt[lat_type]++;
+	if (ts_diff > io_lat->peak_lat[lat_type])
+		io_lat->peak_lat[lat_type] = ts_diff;
 	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
 }
 
 void iostat_update_and_unbind_ctx(struct bio *bio)
+{
+	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
+
+	if (op_is_write(bio_op(bio)) && !op_is_discard(bio_op(bio)))
+		bio->bi_private = iostat_ctx->sbi;
+	else
+		bio->bi_private = iostat_ctx->iostat_private;
+
+	__update_iostat_latency(iostat_ctx);
+	mempool_free(iostat_ctx, bio_iostat_ctx_pool);
+}
+
+void iostat_update_submit_ctx(struct bio *bio, enum page_type type)
 {
 	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
 	enum iostat_lat_type lat_type;
 
-	if (op_is_write(bio_op(bio))) {
+	iostat_ctx->submit_ts = jiffies;
+
+	if (type == DISCARD) {
+		lat_type = DISCARD_LAT;
+	} else if (op_is_write(bio_op(bio))) {
 		lat_type = bio->bi_opf & REQ_SYNC ?
-				WRITE_SYNC_IO : WRITE_ASYNC_IO;
-		bio->bi_private = iostat_ctx->sbi;
+				WRITE_SYNC_DATA_LAT : WRITE_ASYNC_DATA_LAT;
+		lat_type += type;
 	} else {
-		lat_type = READ_IO;
-		bio->bi_private = iostat_ctx->post_read_ctx;
+		lat_type = READ_DATA_LAT;
+		lat_type += type;
 	}
 
-	__update_iostat_latency(iostat_ctx, lat_type);
-	mempool_free(iostat_ctx, bio_iostat_ctx_pool);
+	iostat_ctx->lat_type = lat_type;
 }
 
 void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
-		struct bio *bio, struct bio_post_read_ctx *ctx)
+		struct bio *bio, void *private)
 {
 	struct bio_iostat_ctx *iostat_ctx;
 	/* Due to the mempool, this never fails. */
 	iostat_ctx = mempool_alloc(bio_iostat_ctx_pool, GFP_NOFS);
 	iostat_ctx->sbi = sbi;
 	iostat_ctx->submit_ts = 0;
-	iostat_ctx->type = 0;
-	iostat_ctx->post_read_ctx = ctx;
+	iostat_ctx->lat_type = 0;
+	iostat_ctx->iostat_private = private;
 	bio->bi_private = iostat_ctx;
 }
 
diff --git a/fs/f2fs/iostat.h b/fs/f2fs/iostat.h
index eb99d05cf272..824d5a23bc19 100644
--- a/fs/f2fs/iostat.h
+++ b/fs/f2fs/iostat.h
@@ -6,17 +6,24 @@
 #ifndef __F2FS_IOSTAT_H__
 #define __F2FS_IOSTAT_H__
 
+#ifdef CONFIG_F2FS_IOSTAT
+
 struct bio_post_read_ctx;
 
 enum iostat_lat_type {
-	READ_IO = 0,
-	WRITE_SYNC_IO,
-	WRITE_ASYNC_IO,
-	MAX_IO_TYPE,
+	READ_DATA_LAT = 0,
+	READ_NODE_LAT,
+	READ_META_LAT,
+	WRITE_SYNC_DATA_LAT,
+	WRITE_SYNC_NODE_LAT,
+	WRITE_SYNC_META_LAT,
+	WRITE_ASYNC_DATA_LAT,
+	WRITE_ASYNC_NODE_LAT,
+	WRITE_ASYNC_META_LAT,
+	DISCARD_LAT,
+	MAX_LAT_TYPE,
 };
 
-#ifdef CONFIG_F2FS_IOSTAT
-
 #define NUM_PREALLOC_IOSTAT_CTXS	128
 #define DEFAULT_IOSTAT_PERIOD_MS	3000
 #define MIN_IOSTAT_PERIOD_MS		100
@@ -24,9 +31,9 @@ enum iostat_lat_type {
 #define MAX_IOSTAT_PERIOD_MS		8640000
 
 struct iostat_lat_info {
-	unsigned long sum_lat[MAX_IO_TYPE][NR_PAGE_TYPE];	/* sum of io latencies */
-	unsigned long peak_lat[MAX_IO_TYPE][NR_PAGE_TYPE];	/* peak io latency */
-	unsigned int bio_cnt[MAX_IO_TYPE][NR_PAGE_TYPE];	/* bio count */
+	unsigned long sum_lat[MAX_LAT_TYPE];	/* sum of io latencies */
+	unsigned long peak_lat[MAX_LAT_TYPE];	/* peak io latency */
+	unsigned int bio_cnt[MAX_LAT_TYPE];	/* bio count */
 };
 
 extern int __maybe_unused iostat_info_seq_show(struct seq_file *seq,
@@ -38,29 +45,21 @@ extern void f2fs_update_iostat(struct f2fs_sb_info *sbi, struct inode *inode,
 struct bio_iostat_ctx {
 	struct f2fs_sb_info *sbi;
 	unsigned long submit_ts;
-	enum page_type type;
-	struct bio_post_read_ctx *post_read_ctx;
+	enum iostat_lat_type lat_type;
+	void *iostat_private;
 };
 
-static inline void iostat_update_submit_ctx(struct bio *bio,
-			enum page_type type)
-{
-	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
-
-	iostat_ctx->submit_ts = jiffies;
-	iostat_ctx->type = type;
-}
-
-static inline struct bio_post_read_ctx *get_post_read_ctx(struct bio *bio)
+static inline struct bio_post_read_ctx *get_bio_iostat_private(struct bio *bio)
 {
 	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
 
-	return iostat_ctx->post_read_ctx;
+	return iostat_ctx->iostat_private;
 }
 
+extern void iostat_update_submit_ctx(struct bio *bio, enum page_type type);
 extern void iostat_update_and_unbind_ctx(struct bio *bio);
 extern void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
-		struct bio *bio, struct bio_post_read_ctx *ctx);
+		struct bio *bio, void *private);
 extern int f2fs_init_iostat_processing(void);
 extern void f2fs_destroy_iostat_processing(void);
 extern int f2fs_init_iostat(struct f2fs_sb_info *sbi);
@@ -70,10 +69,10 @@ static inline void f2fs_update_iostat(struct f2fs_sb_info *sbi, struct inode *in
 		enum iostat_type type, unsigned long long io_bytes) {}
 static inline void iostat_update_and_unbind_ctx(struct bio *bio) {}
 static inline void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
-		struct bio *bio, struct bio_post_read_ctx *ctx) {}
+		struct bio *bio, void *private) {}
 static inline void iostat_update_submit_ctx(struct bio *bio,
 		enum page_type type) {}
-static inline struct bio_post_read_ctx *get_post_read_ctx(struct bio *bio)
+static inline struct bio_post_read_ctx *get_bio_iostat_private(struct bio *bio)
 {
 	return bio->bi_private;
 }
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 227e25836173..9a6c45a62e8b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1012,9 +1012,12 @@ static void __remove_discard_cmd(struct f2fs_sb_info *sbi,
 
 static void f2fs_submit_discard_endio(struct bio *bio)
 {
-	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
+	struct discard_cmd *dc;
 	unsigned long flags;
 
+	iostat_update_and_unbind_ctx(bio);
+	dc = bio->bi_private;
+
 	spin_lock_irqsave(&dc->lock, flags);
 	if (!dc->error)
 		dc->error = blk_status_to_errno(bio->bi_status);
@@ -1188,6 +1191,9 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
 		bio->bi_private = dc;
 		bio->bi_end_io = f2fs_submit_discard_endio;
 		bio->bi_opf |= flag;
+
+		iostat_alloc_and_bind_ctx(sbi, bio, dc);
+		iostat_update_submit_ctx(bio, DISCARD);
 		submit_bio(bio);
 
 		atomic_inc(&dcc->issued_discard);
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 1322d34a5dfc..a0b115cf505c 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -2045,7 +2045,7 @@ struct f2fs_iostat_latency {
 
 TRACE_EVENT(f2fs_iostat_latency,
 
-	TP_PROTO(struct f2fs_sb_info *sbi, struct f2fs_iostat_latency (*iostat_lat)[NR_PAGE_TYPE]),
+	TP_PROTO(struct f2fs_sb_info *sbi, struct f2fs_iostat_latency *iostat_lat),
 
 	TP_ARGS(sbi, iostat_lat),
 
@@ -2078,37 +2078,43 @@ TRACE_EVENT(f2fs_iostat_latency,
 		__field(unsigned int,	m_wr_as_peak)
 		__field(unsigned int,	m_wr_as_avg)
 		__field(unsigned int,	m_wr_as_cnt)
+		__field(unsigned int,	discard_peak)
+		__field(unsigned int,	discard_avg)
+		__field(unsigned int,	discard_cnt)
 	),
 
 	TP_fast_assign(
 		__entry->dev		= sbi->sb->s_dev;
-		__entry->d_rd_peak	= iostat_lat[READ_IO][DATA].peak_lat;
-		__entry->d_rd_avg	= iostat_lat[READ_IO][DATA].avg_lat;
-		__entry->d_rd_cnt	= iostat_lat[READ_IO][DATA].cnt;
-		__entry->n_rd_peak	= iostat_lat[READ_IO][NODE].peak_lat;
-		__entry->n_rd_avg	= iostat_lat[READ_IO][NODE].avg_lat;
-		__entry->n_rd_cnt	= iostat_lat[READ_IO][NODE].cnt;
-		__entry->m_rd_peak	= iostat_lat[READ_IO][META].peak_lat;
-		__entry->m_rd_avg	= iostat_lat[READ_IO][META].avg_lat;
-		__entry->m_rd_cnt	= iostat_lat[READ_IO][META].cnt;
-		__entry->d_wr_s_peak	= iostat_lat[WRITE_SYNC_IO][DATA].peak_lat;
-		__entry->d_wr_s_avg	= iostat_lat[WRITE_SYNC_IO][DATA].avg_lat;
-		__entry->d_wr_s_cnt	= iostat_lat[WRITE_SYNC_IO][DATA].cnt;
-		__entry->n_wr_s_peak	= iostat_lat[WRITE_SYNC_IO][NODE].peak_lat;
-		__entry->n_wr_s_avg	= iostat_lat[WRITE_SYNC_IO][NODE].avg_lat;
-		__entry->n_wr_s_cnt	= iostat_lat[WRITE_SYNC_IO][NODE].cnt;
-		__entry->m_wr_s_peak	= iostat_lat[WRITE_SYNC_IO][META].peak_lat;
-		__entry->m_wr_s_avg	= iostat_lat[WRITE_SYNC_IO][META].avg_lat;
-		__entry->m_wr_s_cnt	= iostat_lat[WRITE_SYNC_IO][META].cnt;
-		__entry->d_wr_as_peak	= iostat_lat[WRITE_ASYNC_IO][DATA].peak_lat;
-		__entry->d_wr_as_avg	= iostat_lat[WRITE_ASYNC_IO][DATA].avg_lat;
-		__entry->d_wr_as_cnt	= iostat_lat[WRITE_ASYNC_IO][DATA].cnt;
-		__entry->n_wr_as_peak	= iostat_lat[WRITE_ASYNC_IO][NODE].peak_lat;
-		__entry->n_wr_as_avg	= iostat_lat[WRITE_ASYNC_IO][NODE].avg_lat;
-		__entry->n_wr_as_cnt	= iostat_lat[WRITE_ASYNC_IO][NODE].cnt;
-		__entry->m_wr_as_peak	= iostat_lat[WRITE_ASYNC_IO][META].peak_lat;
-		__entry->m_wr_as_avg	= iostat_lat[WRITE_ASYNC_IO][META].avg_lat;
-		__entry->m_wr_as_cnt	= iostat_lat[WRITE_ASYNC_IO][META].cnt;
+		__entry->d_rd_peak	= iostat_lat[READ_DATA_LAT].peak_lat;
+		__entry->d_rd_avg	= iostat_lat[READ_DATA_LAT].avg_lat;
+		__entry->d_rd_cnt	= iostat_lat[READ_DATA_LAT].cnt;
+		__entry->n_rd_peak	= iostat_lat[READ_NODE_LAT].peak_lat;
+		__entry->n_rd_avg	= iostat_lat[READ_NODE_LAT].avg_lat;
+		__entry->n_rd_cnt	= iostat_lat[READ_NODE_LAT].cnt;
+		__entry->m_rd_peak	= iostat_lat[READ_META_LAT].peak_lat;
+		__entry->m_rd_avg	= iostat_lat[READ_META_LAT].avg_lat;
+		__entry->m_rd_cnt	= iostat_lat[READ_META_LAT].cnt;
+		__entry->d_wr_s_peak	= iostat_lat[WRITE_SYNC_DATA_LAT].peak_lat;
+		__entry->d_wr_s_avg	= iostat_lat[WRITE_SYNC_DATA_LAT].avg_lat;
+		__entry->d_wr_s_cnt	= iostat_lat[WRITE_SYNC_DATA_LAT].cnt;
+		__entry->n_wr_s_peak	= iostat_lat[WRITE_SYNC_NODE_LAT].peak_lat;
+		__entry->n_wr_s_avg	= iostat_lat[WRITE_SYNC_NODE_LAT].avg_lat;
+		__entry->n_wr_s_cnt	= iostat_lat[WRITE_SYNC_NODE_LAT].cnt;
+		__entry->m_wr_s_peak	= iostat_lat[WRITE_SYNC_META_LAT].peak_lat;
+		__entry->m_wr_s_avg	= iostat_lat[WRITE_SYNC_META_LAT].avg_lat;
+		__entry->m_wr_s_cnt	= iostat_lat[WRITE_SYNC_META_LAT].cnt;
+		__entry->d_wr_as_peak	= iostat_lat[WRITE_ASYNC_DATA_LAT].peak_lat;
+		__entry->d_wr_as_avg	= iostat_lat[WRITE_ASYNC_DATA_LAT].avg_lat;
+		__entry->d_wr_as_cnt	= iostat_lat[WRITE_ASYNC_DATA_LAT].cnt;
+		__entry->n_wr_as_peak	= iostat_lat[WRITE_ASYNC_NODE_LAT].peak_lat;
+		__entry->n_wr_as_avg	= iostat_lat[WRITE_ASYNC_NODE_LAT].avg_lat;
+		__entry->n_wr_as_cnt	= iostat_lat[WRITE_ASYNC_NODE_LAT].cnt;
+		__entry->m_wr_as_peak	= iostat_lat[WRITE_ASYNC_META_LAT].peak_lat;
+		__entry->m_wr_as_avg	= iostat_lat[WRITE_ASYNC_META_LAT].avg_lat;
+		__entry->m_wr_as_cnt	= iostat_lat[WRITE_ASYNC_META_LAT].cnt;
+		__entry->discard_peak	= iostat_lat[DISCARD_LAT].peak_lat;
+		__entry->discard_avg	= iostat_lat[DISCARD_LAT].avg_lat;
+		__entry->discard_cnt	= iostat_lat[DISCARD_LAT].cnt;
 	),
 
 	TP_printk("dev = (%d,%d), "
@@ -2116,7 +2122,8 @@ TRACE_EVENT(f2fs_iostat_latency,
 		"rd_data [%u/%u/%u], rd_node [%u/%u/%u], rd_meta [%u/%u/%u], "
 		"wr_sync_data [%u/%u/%u], wr_sync_node [%u/%u/%u], "
 		"wr_sync_meta [%u/%u/%u], wr_async_data [%u/%u/%u], "
-		"wr_async_node [%u/%u/%u], wr_async_meta [%u/%u/%u]",
+		"wr_async_node [%u/%u/%u], wr_async_meta [%u/%u/%u], "
+		"discard [%u/%u/%u]",
 		show_dev(__entry->dev),
 		__entry->d_rd_peak, __entry->d_rd_avg, __entry->d_rd_cnt,
 		__entry->n_rd_peak, __entry->n_rd_avg, __entry->n_rd_cnt,
@@ -2126,7 +2133,8 @@ TRACE_EVENT(f2fs_iostat_latency,
 		__entry->m_wr_s_peak, __entry->m_wr_s_avg, __entry->m_wr_s_cnt,
 		__entry->d_wr_as_peak, __entry->d_wr_as_avg, __entry->d_wr_as_cnt,
 		__entry->n_wr_as_peak, __entry->n_wr_as_avg, __entry->n_wr_as_cnt,
-		__entry->m_wr_as_peak, __entry->m_wr_as_avg, __entry->m_wr_as_cnt)
+		__entry->m_wr_as_peak, __entry->m_wr_as_avg, __entry->m_wr_as_cnt,
+		__entry->discard_peak, __entry->discard_avg, __entry->discard_cnt)
 );
 #endif
 
-- 
2.25.1

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