Message-ID: <50af6bb4-0e90-f210-f684-470ab92f62cd@kernel.org>
Date:   Tue, 31 Jan 2023 09:56:58 +0800
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Subject: Re: [PATCH] f2fs: use iostat_lat_type directly as a parameter in the
 iostat_update_and_unbind_ctx()
Content-Language: en-US
To:     Jaegeuk Kim <jaegeuk@kernel.org>
Cc:     Yangtao Li <frank.li@vivo.com>,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
References: <20230105042240.24738-1-frank.li@vivo.com>
 <8ab26acd-4df6-8330-8e82-1d258d9f0d6d@kernel.org>
 <Y9g4PcQvsCOj1d0r@google.com>
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <Y9g4PcQvsCOj1d0r@google.com>
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On 2023/1/31 5:35, Jaegeuk Kim wrote:
> On 01/28, Chao Yu wrote:
>> On 2023/1/5 12:22, Yangtao Li wrote:
>>> Convert to use iostat_lat_type as parameter instead of raw number.
>>> BTW, move NUM_PREALLOC_IOSTAT_CTXS to the header file, and rename
>>> iotype to page_type to match the definition.
>>>
>>> Signed-off-by: Yangtao Li <frank.li@vivo.com>
>>> ---
>>>    fs/f2fs/data.c   |  5 +++--
>>>    fs/f2fs/iostat.c | 34 +++++++++++-----------------------
>>>    fs/f2fs/iostat.h | 19 ++++++++++---------
>>>    3 files changed, 24 insertions(+), 34 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index c940da1c540f..4e8fd5697c42 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -292,7 +292,7 @@ static void f2fs_read_end_io(struct bio *bio)
>>>    	struct bio_post_read_ctx *ctx;
>>>    	bool intask = in_task();
>>> -	iostat_update_and_unbind_ctx(bio, 0);
>>> +	iostat_update_and_unbind_ctx(bio, READ_IO);
>>>    	ctx = bio->bi_private;
>>>    	if (time_to_inject(sbi, FAULT_READ_IO))
>>> @@ -330,7 +330,8 @@ static void f2fs_write_end_io(struct bio *bio)
>>>    	struct bio_vec *bvec;
>>>    	struct bvec_iter_all iter_all;
>>> -	iostat_update_and_unbind_ctx(bio, 1);
>>> +	iostat_update_and_unbind_ctx(bio, bio->bi_opf & REQ_SYNC ? WRITE_SYNC_IO :
>>> +										WRITE_ASYNC_IO);
>>
>> We can use op_is_write(bio_op(bio)) to check IO's rw type, why not just
>> passing bio arguement, and parse rw/sync types from bio inside
>> iostat_update_and_unbind_ctx(), it can avoid passing unneeded arguements.
> 
> Chao, let's write another patch to clean up, if you're interested in.

Jaegeuk, it's fine, will send a separated patch to clean up parameters.

Thanks,

> 
>>
>> Thanks,
>>
>>>    	sbi = bio->bi_private;
>>>    	if (time_to_inject(sbi, FAULT_WRITE_IO))
>>> diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
>>> index 59c72f92191a..20944c4a683a 100644
>>> --- a/fs/f2fs/iostat.c
>>> +++ b/fs/f2fs/iostat.c
>>> @@ -14,7 +14,6 @@
>>>    #include "iostat.h"
>>>    #include <trace/events/f2fs.h>
>>> -#define NUM_PREALLOC_IOSTAT_CTXS	128
>>>    static struct kmem_cache *bio_iostat_ctx_cache;
>>>    static mempool_t *bio_iostat_ctx_pool;
>>> @@ -210,49 +209,38 @@ void f2fs_update_iostat(struct f2fs_sb_info *sbi, struct inode *inode,
>>>    }
>>>    static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
>>> -				int rw, bool is_sync)
>>> +				enum iostat_lat_type type)
>>>    {
>>>    	unsigned long ts_diff;
>>> -	unsigned int iotype = iostat_ctx->type;
>>> +	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;
>>> -	int idx;
>>>    	unsigned long flags;
>>>    	if (!sbi->iostat_enable)
>>>    		return;
>>>    	ts_diff = jiffies - iostat_ctx->submit_ts;
>>> -	if (iotype >= META_FLUSH)
>>> -		iotype = META;
>>> -
>>> -	if (rw == 0) {
>>> -		idx = READ_IO;
>>> -	} else {
>>> -		if (is_sync)
>>> -			idx = WRITE_SYNC_IO;
>>> -		else
>>> -			idx = WRITE_ASYNC_IO;
>>> -	}
>>> +	if (page_type >= META_FLUSH)
>>> +		page_type = META;
>>>    	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
>>> -	io_lat->sum_lat[idx][iotype] += ts_diff;
>>> -	io_lat->bio_cnt[idx][iotype]++;
>>> -	if (ts_diff > io_lat->peak_lat[idx][iotype])
>>> -		io_lat->peak_lat[idx][iotype] = ts_diff;
>>> +	io_lat->sum_lat[type][page_type] += ts_diff;
>>> +	io_lat->bio_cnt[type][page_type]++;
>>> +	if (ts_diff > io_lat->peak_lat[type][page_type])
>>> +		io_lat->peak_lat[type][page_type] = ts_diff;
>>>    	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
>>>    }
>>> -void iostat_update_and_unbind_ctx(struct bio *bio, int rw)
>>> +void iostat_update_and_unbind_ctx(struct bio *bio, enum iostat_lat_type type)
>>>    {
>>>    	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
>>> -	bool is_sync = bio->bi_opf & REQ_SYNC;
>>> -	if (rw == 0)
>>> +	if (type == READ_IO)
>>>    		bio->bi_private = iostat_ctx->post_read_ctx;
>>>    	else
>>>    		bio->bi_private = iostat_ctx->sbi;
>>> -	__update_iostat_latency(iostat_ctx, rw, is_sync);
>>> +	__update_iostat_latency(iostat_ctx, type);
>>>    	mempool_free(iostat_ctx, bio_iostat_ctx_pool);
>>>    }
>>> diff --git a/fs/f2fs/iostat.h b/fs/f2fs/iostat.h
>>> index 2c048307b6e0..1f827a2fe6b2 100644
>>> --- a/fs/f2fs/iostat.h
>>> +++ b/fs/f2fs/iostat.h
>>> @@ -8,20 +8,21 @@
>>>    struct bio_post_read_ctx;
>>> +enum iostat_lat_type {
>>> +	READ_IO = 0,
>>> +	WRITE_SYNC_IO,
>>> +	WRITE_ASYNC_IO,
>>> +	MAX_IO_TYPE,
>>> +};
>>> +
>>>    #ifdef CONFIG_F2FS_IOSTAT
>>> +#define NUM_PREALLOC_IOSTAT_CTXS	128
>>>    #define DEFAULT_IOSTAT_PERIOD_MS	3000
>>>    #define MIN_IOSTAT_PERIOD_MS		100
>>>    /* maximum period of iostat tracing is 1 day */
>>>    #define MAX_IOSTAT_PERIOD_MS		8640000
>>> -enum {
>>> -	READ_IO,
>>> -	WRITE_SYNC_IO,
>>> -	WRITE_ASYNC_IO,
>>> -	MAX_IO_TYPE,
>>> -};
>>> -
>>>    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 */
>>> @@ -57,7 +58,7 @@ static inline struct bio_post_read_ctx *get_post_read_ctx(struct bio *bio)
>>>    	return iostat_ctx->post_read_ctx;
>>>    }
>>> -extern void iostat_update_and_unbind_ctx(struct bio *bio, int rw);
>>> +extern void iostat_update_and_unbind_ctx(struct bio *bio, enum iostat_lat_type type);
>>>    extern void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
>>>    		struct bio *bio, struct bio_post_read_ctx *ctx);
>>>    extern int f2fs_init_iostat_processing(void);
>>> @@ -67,7 +68,7 @@ extern void f2fs_destroy_iostat(struct f2fs_sb_info *sbi);
>>>    #else
>>>    static inline void f2fs_update_iostat(struct f2fs_sb_info *sbi, struct inode *inode,
>>>    		enum iostat_type type, unsigned long long io_bytes) {}
>>> -static inline void iostat_update_and_unbind_ctx(struct bio *bio, int rw) {}
>>> +static inline void iostat_update_and_unbind_ctx(struct bio *bio, enum iostat_lat_type type) {}
>>>    static inline void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
>>>    		struct bio *bio, struct bio_post_read_ctx *ctx) {}
>>>    static inline void iostat_update_submit_ctx(struct bio *bio,