Hi Kim, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk.kim@xxxxxxxxxxx] > Sent: Monday, November 18, 2013 8:29 AM > To: Chao Yu > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; 谭姝 > Subject: Re: [f2fs-dev] [PATCH V2 1/2] f2fs: add a new function to support for merging contiguous read > > Hi Chao, > > 2013-11-16 (토), 14:14 +0800, Chao Yu: > > For better read performance, we add a new function to support for merging contiguous read as the one for write. > > Please consider 80 columns for the description. > I cannot fix this at every time though. :( Got it, sorry about my carelessness in previous patch. > > > > > v1-->v2: > > o add declarations here as Gu Zheng suggested. > > > > Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx> > > Acked-by: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> > > --- > > fs/f2fs/data.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > > fs/f2fs/f2fs.h | 4 ++++ > > 2 files changed, 49 insertions(+) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index aa3438c..18107cb 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -404,6 +404,51 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, > > return 0; > > } > > > > +void f2fs_submit_read_bio(struct f2fs_sb_info *sbi, int rw) > > +{ > > + down_read(&sbi->bio_sem); > > Is there any reason to use down_read()? Isn't that we use bio_sem to let w/r or w/w submitting be mutex? > It seems that we need to declare sbi->bio_read and sbi->bio_write > instead of sbi->bio_sem. > In addition to that, we need to use down_write(&sbi->bio_read) here. If so, it looks similar between (struct rw_semaphore) sbi->bio_read and (struct bio *) sbi->read_bio. How about using read_bio_sem/rbio_sem to differentiate from sbi->read_bio? > > > + if (sbi->read_bio) { > > + submit_bio(rw, sbi->read_bio); > > + sbi->read_bio = NULL; > > + } > > + up_read(&sbi->bio_sem); > > up_write(&sbi->bio_read); > > > +} > > + > > +void submit_read_page(struct f2fs_sb_info *sbi, struct page *page, > > + block_t blk_addr, int rw) > > +{ > > + struct block_device *bdev = sbi->sb->s_bdev; > > + int bio_blocks; > > + > > + verify_block_addr(sbi, blk_addr); > > + > > + down_read(&sbi->bio_sem); > > down_write(&sbi->bio_read); > > > + > > + if (sbi->read_bio && sbi->last_read_block != blk_addr - 1) { > > + submit_bio(rw, sbi->read_bio); > > + sbi->read_bio = NULL; > > + } > > + > > +alloc_new: > > + if (sbi->read_bio == NULL) { > > + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); > > + sbi->read_bio = f2fs_bio_alloc(bdev, bio_blocks); > > + sbi->read_bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); > > + sbi->read_bio->bi_end_io = read_end_io; > > + } > > + > > + if (bio_add_page(sbi->read_bio, page, PAGE_CACHE_SIZE, 0) < > > + PAGE_CACHE_SIZE) { > > + submit_bio(rw, sbi->read_bio); > > + sbi->read_bio = NULL; > > + goto alloc_new; > > + } > > + > > + sbi->last_read_block = blk_addr; > > + > > + up_read(&sbi->bio_sem); > > up_write(&sbi->bio_read); > > > +} > > + > > /* > > * This function should be used by the data read flow only where it > > * does not check the "create" flag that indicates block allocation. > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index 89dc750..bfe9d87 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -359,6 +359,8 @@ struct f2fs_sb_info { > > > > /* for segment-related operations */ > > struct f2fs_sm_info *sm_info; /* segment manager */ > > + struct bio *read_bio; /* read bios to merge */ > > + sector_t last_read_block; /* last read block number */ > > struct bio *bio[NR_PAGE_TYPE]; /* bios to merge */ > > sector_t last_block_in_bio[NR_PAGE_TYPE]; /* last block number */ > > struct rw_semaphore bio_sem; /* IO semaphore */ > > @@ -1111,6 +1113,8 @@ struct page *find_data_page(struct inode *, pgoff_t, bool); > > struct page *get_lock_data_page(struct inode *, pgoff_t); > > struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool); > > int f2fs_readpage(struct f2fs_sb_info *, struct page *, block_t, int); > > +void f2fs_submit_read_bio(struct f2fs_sb_info *, int); > > +void submit_read_page(struct f2fs_sb_info *, struct page *, block_t, int); > > int do_write_data_page(struct page *); > > > > /* > > -- > Jaegeuk Kim > Samsung -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
