From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933769AbcKNLSy (ORCPT ); Mon, 14 Nov 2016 06:18:54 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:38673 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752337AbcKNLSw (ORCPT ); Mon, 14 Nov 2016 06:18:52 -0500 Subject: Re: [PATCH] f2fs: don't wait writeback for datas during checkpoint To: Jaegeuk Kim References: <20161110114003.90461-1-yuchao0@huawei.com> <20161110200340.GA80797@jaegeuk> CC: , , From: Chao Yu Message-ID: <9bbd02bf-9f9a-0dee-5ad1-45328269af10@huawei.com> Date: Mon, 14 Nov 2016 19:17:43 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <20161110200340.GA80797@jaegeuk> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jaegeuk, On 2016/11/11 4:03, Jaegeuk Kim wrote: > Hi Chao, > > On Thu, Nov 10, 2016 at 07:40:03PM +0800, Chao Yu wrote: >> Normally, while committing checkpoint, we will wait on all pages to be >> writebacked no matter the page is data or metadata, so in scenario where >> there are lots of data IO being submitted with metadata, we may suffer >> long latency for waiting writeback during checkpoint. >> >> Indeed, we only care about persistence for pages with metadata, but not >> pages with data, as file system consistent are only related to metadate, >> so in order to avoid encountering long latency in above scenario, let's >> recognize and reference metadata in submitted IOs, wait writeback only >> for metadatas. >> >> Signed-off-by: Chao Yu >> --- >> fs/f2fs/checkpoint.c | 2 +- >> fs/f2fs/data.c | 9 +++++++-- >> fs/f2fs/debug.c | 7 ++++--- >> fs/f2fs/f2fs.h | 26 +++++++++++++++++++++++--- >> fs/f2fs/gc.c | 2 ++ >> fs/f2fs/node.c | 1 + >> fs/f2fs/segment.c | 2 ++ >> 7 files changed, 40 insertions(+), 9 deletions(-) >> >> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >> index 7bece59..bdf8a50 100644 >> --- a/fs/f2fs/checkpoint.c >> +++ b/fs/f2fs/checkpoint.c >> @@ -1003,7 +1003,7 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi) >> for (;;) { >> prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE); >> >> - if (!atomic_read(&sbi->nr_wb_bios)) >> + if (!get_pages(sbi, F2FS_WB_META)) >> break; >> >> io_schedule_timeout(5*HZ); >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >> index 66d2aee..2fb1ffd 100644 >> --- a/fs/f2fs/data.c >> +++ b/fs/f2fs/data.c >> @@ -73,6 +73,7 @@ static void f2fs_write_end_io(struct bio *bio) >> >> bio_for_each_segment_all(bvec, bio, i) { >> struct page *page = bvec->bv_page; >> + bool is_meta = f2fs_is_meta_data(page); >> >> fscrypt_pullback_bio_page(&page, true); >> >> @@ -80,9 +81,10 @@ static void f2fs_write_end_io(struct bio *bio) >> mapping_set_error(page->mapping, -EIO); >> f2fs_stop_checkpoint(sbi, true); >> } >> + dec_page_count(sbi, is_meta ? F2FS_WB_META : F2FS_WB_DATA); >> end_page_writeback(page); >> } >> - if (atomic_dec_and_test(&sbi->nr_wb_bios) && >> + if (!get_pages(sbi, F2FS_WB_META) && >> wq_has_sleeper(&sbi->cp_wait)) >> wake_up(&sbi->cp_wait); >> >> @@ -111,7 +113,6 @@ static inline void __submit_bio(struct f2fs_sb_info *sbi, >> struct bio *bio, enum page_type type) >> { >> if (!is_read_io(bio_op(bio))) { >> - atomic_inc(&sbi->nr_wb_bios); >> if (f2fs_sb_mounted_blkzoned(sbi->sb) && >> current->plug && (type == DATA || type == NODE)) >> blk_finish_plug(current->plug); >> @@ -272,6 +273,9 @@ void f2fs_submit_page_mbio(struct f2fs_io_info *fio) >> verify_block_addr(sbi, fio->old_blkaddr); >> verify_block_addr(sbi, fio->new_blkaddr); >> >> + if (!is_read) >> + inc_page_count(sbi, fio->is_meta ? F2FS_WB_META : F2FS_WB_DATA); >> + > > How about using f2fs_is_meta_data(page) instead of changing fio? Yes, I've cleaned up codes as you mentioned, and also fix incorrectly handling of GCed encrypted datas. Could you please review the following v2 patch? Thanks, > > Thanks, > >> down_write(&io->io_rwsem); >> >> if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 || >> @@ -1237,6 +1241,7 @@ static int f2fs_write_data_page(struct page *page, >> .type = DATA, >> .op = REQ_OP_WRITE, >> .op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0, >> + .is_meta = S_ISDIR(inode->i_mode), >> .page = page, >> .encrypted_page = NULL, >> }; >> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c >> index 2fdf233..f2d87de 100644 >> --- a/fs/f2fs/debug.c >> +++ b/fs/f2fs/debug.c >> @@ -50,7 +50,8 @@ static void update_general_status(struct f2fs_sb_info *sbi) >> si->ndirty_files = sbi->ndirty_inode[FILE_INODE]; >> si->ndirty_all = sbi->ndirty_inode[DIRTY_META]; >> si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES); >> - si->wb_bios = atomic_read(&sbi->nr_wb_bios); >> + si->nr_wb_meta = get_pages(sbi, F2FS_WB_META); >> + si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA); >> si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg; >> si->rsvd_segs = reserved_segments(sbi); >> si->overp_segs = overprovision_segments(sbi); >> @@ -313,8 +314,8 @@ static int stat_show(struct seq_file *s, void *v) >> seq_printf(s, " - Inner Struct Count: tree: %d(%d), node: %d\n", >> si->ext_tree, si->zombie_tree, si->ext_node); >> seq_puts(s, "\nBalancing F2FS Async:\n"); >> - seq_printf(s, " - inmem: %4d, wb_bios: %4d\n", >> - si->inmem_pages, si->wb_bios); >> + seq_printf(s, " - inmem: %4d, wb_meta: %4d, wb_data: %4d\n", >> + si->inmem_pages, si->nr_wb_meta, si->nr_wb_data); >> seq_printf(s, " - nodes: %4d in %4d\n", >> si->ndirty_node, si->node_pages); >> seq_printf(s, " - dents: %4d in dirs:%4d (%4d)\n", >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >> index 23a937f..95ad091 100644 >> --- a/fs/f2fs/f2fs.h >> +++ b/fs/f2fs/f2fs.h >> @@ -682,6 +682,8 @@ enum count_type { >> F2FS_DIRTY_META, >> F2FS_INMEM_PAGES, >> F2FS_DIRTY_IMETA, >> + F2FS_WB_META, >> + F2FS_WB_DATA, >> NR_COUNT_TYPE, >> }; >> >> @@ -715,6 +717,7 @@ struct f2fs_io_info { >> enum page_type type; /* contains DATA/NODE/META/META_FLUSH */ >> int op; /* contains REQ_OP_ */ >> int op_flags; /* rq_flag_bits */ >> + bool is_meta; /* checkpoint needs to wait its writeback */ >> block_t new_blkaddr; /* new block address to be written */ >> block_t old_blkaddr; /* old block address before Cow */ >> struct page *page; /* page to be written */ >> @@ -849,7 +852,6 @@ struct f2fs_sb_info { >> block_t discard_blks; /* discard command candidats */ >> block_t last_valid_block_count; /* for recovery */ >> u32 s_next_generation; /* for NFS support */ >> - atomic_t nr_wb_bios; /* # of writeback bios */ >> >> /* # of pages, see count_type */ >> atomic_t nr_pages[NR_COUNT_TYPE]; >> @@ -1193,6 +1195,23 @@ static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid) >> return 0; >> } >> >> +static inline bool f2fs_is_meta_data(struct page *page) >> +{ >> + struct address_space *mapping = page->mapping; >> + struct inode *inode; >> + >> + /* it is bounce page of encrypted regular inode */ >> + if (!mapping) >> + return false; >> + >> + inode = mapping->host; >> + if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)) || >> + inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)) || >> + S_ISDIR(inode->i_mode)) >> + return true; >> + return false; >> +} >> + >> #define F2FS_DEFAULT_ALLOCATED_BLOCKS 1 >> >> /* >> @@ -1263,7 +1282,8 @@ static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type) >> { >> atomic_inc(&sbi->nr_pages[count_type]); >> >> - if (count_type == F2FS_DIRTY_DATA || count_type == F2FS_INMEM_PAGES) >> + if (count_type == F2FS_DIRTY_DATA || count_type == F2FS_INMEM_PAGES || >> + count_type == F2FS_WB_META || count_type == F2FS_WB_DATA) >> return; >> >> set_sbi_flag(sbi, SBI_IS_DIRTY); >> @@ -2219,7 +2239,7 @@ struct f2fs_stat_info { >> unsigned int ndirty_dirs, ndirty_files, ndirty_all; >> int nats, dirty_nats, sits, dirty_sits, free_nids, alloc_nids; >> int total_count, utilization; >> - int bg_gc, wb_bios; >> + int bg_gc, nr_wb_meta, nr_wb_data; >> int inline_xattr, inline_inode, inline_dir, orphans; >> unsigned int valid_count, valid_node_count, valid_inode_count, discard_blks; >> unsigned int bimodal, avg_vblocks; >> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >> index f8d8cc96a..6b762d4 100644 >> --- a/fs/f2fs/gc.c >> +++ b/fs/f2fs/gc.c >> @@ -554,6 +554,7 @@ static void move_encrypted_block(struct inode *inode, block_t bidx, >> .type = DATA, >> .op = REQ_OP_READ, >> .op_flags = READ_SYNC, >> + .is_meta = true, >> .encrypted_page = NULL, >> }; >> struct dnode_of_data dn; >> @@ -674,6 +675,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type, >> .type = DATA, >> .op = REQ_OP_WRITE, >> .op_flags = WRITE_SYNC, >> + .is_meta = S_ISDIR(inode->i_mode), >> .page = page, >> .encrypted_page = NULL, >> }; >> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c >> index d58438f..3c7e00c 100644 >> --- a/fs/f2fs/node.c >> +++ b/fs/f2fs/node.c >> @@ -1574,6 +1574,7 @@ static int f2fs_write_node_page(struct page *page, >> .type = NODE, >> .op = REQ_OP_WRITE, >> .op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0, >> + .is_meta = true, >> .page = page, >> .encrypted_page = NULL, >> }; >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >> index 078c571..b34e20a 100644 >> --- a/fs/f2fs/segment.c >> +++ b/fs/f2fs/segment.c >> @@ -261,6 +261,7 @@ static int __commit_inmem_pages(struct inode *inode, >> .type = DATA, >> .op = REQ_OP_WRITE, >> .op_flags = WRITE_SYNC | REQ_PRIO, >> + .is_meta = false, >> .encrypted_page = NULL, >> }; >> bool submit_bio = false; >> @@ -1573,6 +1574,7 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct page *page) >> .type = META, >> .op = REQ_OP_WRITE, >> .op_flags = WRITE_SYNC | REQ_META | REQ_PRIO, >> + .is_meta = true, >> .old_blkaddr = page->index, >> .new_blkaddr = page->index, >> .page = page, >> -- >> 2.8.2.311.gee88674 > > . >