Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 19 Apr 2023 13:32:03 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Yangtao Li <frank.li@vivo.com>
Cc:     Chao Yu <chao@kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/2] f2fs: refactor struct iostat_lat_info
Message-ID: <ZEBPwz4fJATKs22g@google.com>
References: <20230407174609.4939-1-frank.li@vivo.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230407174609.4939-1-frank.li@vivo.com>
Precedence: bulk

On 04/08, Yangtao Li wrote:
> The current code uses a mixture of MAX_IO_TYPE and NR_PAGE_TYPE
> to form lat_type, and uses a two-dimensional array to store data.
> NR_PAGE_TYPE is 3, which is unreasonable for a discard with a
> PAGE_TYPE of 1. So this patch changes the array to a 1D array and
> does some cleanup.
> 
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> ---
>  fs/f2fs/data.c              |  2 +-
>  fs/f2fs/iostat.c            | 79 +++++++++++++++++++++----------------
>  fs/f2fs/iostat.h            | 49 +++++++++++------------
>  include/trace/events/f2fs.h | 56 +++++++++++++-------------
>  4 files changed, 97 insertions(+), 89 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index e975f9c702ab..38cab984496f 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -2311,7 +2311,7 @@ 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 = iostat_get_bio_private(bio);

This ctx is not used for iostat.

>  		ctx->enabled_steps |= STEP_DECOMPRESS;
>  		refcount_inc(&dic->refcnt);
>  
> diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
> index 3d5bfb1ad585..5d496d5b70d3 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 +206,73 @@ 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)))
> +		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;
>  
> +	iostat_ctx->submit_ts = jiffies;
> +
>  	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 = (enum iostat_lat_type)(lat_type + type);
>  	} else {
> -		lat_type = READ_IO;
> -		bio->bi_private = iostat_ctx->post_read_ctx;
> +		lat_type = READ_DATA_LAT;
> +		lat_type = (enum iostat_lat_type)(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..67b468691498 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 *iostat_get_bio_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 *iostat_get_bio_private(struct bio *bio)
>  {
>  	return bio->bi_private;
>  }
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index 99cbc5949e3c..040a430e1199 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),
>  
> @@ -2082,33 +2082,33 @@ TRACE_EVENT(f2fs_iostat_latency,
>  
>  	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;
>  	),
>  
>  	TP_printk("dev = (%d,%d), "
> -- 
> 2.35.1