Hi Chao, On 05/09, Chao Yu wrote: > From: Chao Yu <[email protected]> > > Serialize data/node IOs by using fifo list instead of mutex lock, > it will help to enhance concurrency of f2fs, meanwhile keeping LFS > IO semantics.
I'm not against to give it a try, but not sure how much we can get a benefit from this approach frankly. Have you got a trouble on any lock contention from the below io_rwsem or mutex? Thanks, > > Signed-off-by: Chao Yu <[email protected]> > --- > fs/f2fs/checkpoint.c | 1 + > fs/f2fs/data.c | 28 ++++++++++++++++++++++++---- > fs/f2fs/f2fs.h | 5 ++++- > fs/f2fs/gc.c | 3 ++- > fs/f2fs/segment.c | 20 ++++++++++++++------ > fs/f2fs/segment.h | 3 ++- > 6 files changed, 47 insertions(+), 13 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 2a475e83a092..7b3393474f6b 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -162,6 +162,7 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, block_t > start, int nrpages, > .op = REQ_OP_READ, > .op_flags = sync ? (REQ_META | REQ_PRIO) : REQ_RAHEAD, > .encrypted_page = NULL, > + .in_list = false, > }; > struct blk_plug plug; > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 5f001b471252..89eaa8aaa97b 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -393,10 +393,28 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio) > struct f2fs_bio_info *io; > bool is_read = is_read_io(fio->op); > struct page *bio_page; > + struct curseg_info *curseg; > int err = 0; > > + if (fio->in_list) > + curseg = CURSEG_I(sbi, fio->seg_type); > + > io = __get_bio_info(sbi, fio->op, fio->type, fio->seg_type); > > + down_write(&io->io_rwsem); > +next: > + if (fio->in_list) { > + spin_lock(&curseg->io_lock); > + if (list_empty(&curseg->io_list)) { > + spin_unlock(&curseg->io_lock); > + goto out_fail; > + } > + fio = list_first_entry(&curseg->io_list, > + struct f2fs_io_info, list); > + list_del(&fio->list); > + spin_unlock(&curseg->io_lock); > + } > + > if (fio->old_blkaddr != NEW_ADDR) > verify_block_addr(sbi, fio->old_blkaddr); > verify_block_addr(sbi, fio->new_blkaddr); > @@ -409,8 +427,6 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio) > if (!is_read) > inc_page_count(sbi, WB_DATA_TYPE(bio_page)); > > - down_write(&io->io_rwsem); > - > if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 || > (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) || > !__same_bdev(sbi, fio->new_blkaddr, io->bio))) > @@ -437,9 +453,13 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio) > > io->last_block_in_bio = fio->new_blkaddr; > f2fs_trace_ios(fio, 0); > + > + trace_f2fs_submit_page_mbio(fio->page, fio); > + > + if (fio->in_list) > + goto next; > out_fail: > up_write(&io->io_rwsem); > - trace_f2fs_submit_page_mbio(fio->page, fio); > return err; > } > > @@ -752,7 +772,7 @@ static int __allocate_data_block(struct dnode_of_data *dn) > set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version); > > allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr, > - &sum, CURSEG_WARM_DATA); > + &sum, CURSEG_WARM_DATA, NULL, false); > set_data_blkaddr(dn); > > /* update i_size */ > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 9129a6229bc8..6b8e9f051aa2 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -802,8 +802,10 @@ struct f2fs_io_info { > block_t old_blkaddr; /* old block address before Cow */ > struct page *page; /* page to be written */ > struct page *encrypted_page; /* encrypted page */ > + struct list_head list; /* serialize IOs */ > bool submitted; /* indicate IO submission */ > bool need_lock; /* indicate we need to lock cp_rwsem */ > + bool in_list; /* indicate fio is in io_list */ > }; > > #define is_read_io(rw) ((rw) == READ) > @@ -2274,7 +2276,8 @@ void f2fs_replace_block(struct f2fs_sb_info *sbi, > struct dnode_of_data *dn, > bool recover_newaddr); > void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > block_t old_blkaddr, block_t *new_blkaddr, > - struct f2fs_summary *sum, int type); > + struct f2fs_summary *sum, int type, > + struct f2fs_io_info *fio, bool add_list); > void f2fs_wait_on_page_writeback(struct page *page, > enum page_type type, bool ordered); > void f2fs_wait_on_encrypted_page_writeback(struct f2fs_sb_info *sbi, > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index 8b267ca30926..ac2f74e40eea 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -590,6 +590,7 @@ static void move_encrypted_block(struct inode *inode, > block_t bidx, > .op = REQ_OP_READ, > .op_flags = 0, > .encrypted_page = NULL, > + .in_list = false, > }; > struct dnode_of_data dn; > struct f2fs_summary sum; > @@ -633,7 +634,7 @@ static void move_encrypted_block(struct inode *inode, > block_t bidx, > fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; > > allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, > - &sum, fio.seg_type); > + &sum, fio.seg_type, NULL, false); > > fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr, > FGP_LOCK | FGP_CREAT, GFP_NOFS); > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index c047b5d8b9d3..d4975b8f4620 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -2100,7 +2100,8 @@ static int __get_segment_type(struct page *page, enum > page_type p_type) > > void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > block_t old_blkaddr, block_t *new_blkaddr, > - struct f2fs_summary *sum, int type) > + struct f2fs_summary *sum, int type, > + struct f2fs_io_info *fio, bool add_list) > { > struct sit_info *sit_i = SIT_I(sbi); > struct curseg_info *curseg = CURSEG_I(sbi, type); > @@ -2136,6 +2137,14 @@ void allocate_data_block(struct f2fs_sb_info *sbi, > struct page *page, > if (page && IS_NODESEG(type)) > fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg)); > > + if (add_list) { > + INIT_LIST_HEAD(&fio->list); > + fio->in_list = true; > + spin_lock(&curseg->io_lock); > + list_add_tail(&fio->list, &curseg->io_list); > + spin_unlock(&curseg->io_lock); > + } > + > mutex_unlock(&curseg->curseg_mutex); > } > > @@ -2145,10 +2154,9 @@ static void do_write_page(struct f2fs_summary *sum, > struct f2fs_io_info *fio) > > fio->seg_type = __get_segment_type(fio->page, fio->type); > > - mutex_lock(&CURSEG_I(fio->sbi, fio->seg_type)->wio_mutex); > reallocate: > allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr, > - &fio->new_blkaddr, sum, fio->seg_type); > + &fio->new_blkaddr, sum, fio->seg_type, fio, true); > > /* writeout dirty page into bdev */ > err = f2fs_submit_page_mbio(fio); > @@ -2156,8 +2164,6 @@ static void do_write_page(struct f2fs_summary *sum, > struct f2fs_io_info *fio) > fio->old_blkaddr = fio->new_blkaddr; > goto reallocate; > } > - > - mutex_unlock(&CURSEG_I(fio->sbi, fio->seg_type)->wio_mutex); > } > > void write_meta_page(struct f2fs_sb_info *sbi, struct page *page) > @@ -2171,6 +2177,7 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct > page *page) > .new_blkaddr = page->index, > .page = page, > .encrypted_page = NULL, > + .in_list = false, > }; > > if (unlikely(page->index >= MAIN_BLKADDR(sbi))) > @@ -2978,7 +2985,8 @@ static int build_curseg(struct f2fs_sb_info *sbi) > array[i].bio_info.sbi = sbi; > array[i].bio_info.bio = NULL; > > - mutex_init(&array[i].wio_mutex); > + spin_lock_init(&array[i].io_lock); > + INIT_LIST_HEAD(&array[i].io_list); > } > return restore_curseg_summaries(sbi); > } > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > index 701944b462cd..b6f5dffeaa61 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -283,7 +283,8 @@ struct curseg_info { > struct rw_semaphore journal_rwsem; /* protect journal area */ > struct f2fs_journal *journal; /* cached journal info */ > struct f2fs_bio_info bio_info; /* for log bios */ > - struct mutex wio_mutex; /* serialize DATA/NODE IOs */ > + spinlock_t io_lock; /* serialize DATA/NODE IOs */ > + struct list_head io_list; /* tracking fios */ > unsigned char alloc_type; /* current allocation type */ > unsigned int segno; /* current segment number */ > unsigned short next_blkoff; /* next block offset to write */ > -- > 2.12.2.575.gb14f27f ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
