On 2018/8/14 4:11, Jaegeuk Kim wrote: > On 08/13, Chao Yu wrote: >> Hi Jaegeuk, >> >> On 2018/8/11 2:56, Jaegeuk Kim wrote: >>> This reverts the commit - "b93f771 - f2fs: remove writepages lock" >>> to fix the drop in sequential read throughput. >>> >>> Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L >>> device: UFS >>> >>> Before - >>> read throughput: 185 MB/s >>> total read requests: 85177 (of these ~80000 are 4KB size requests). >>> total write requests: 2546 (of these ~2208 requests are written in 512KB). >>> >>> After - >>> read throughput: 758 MB/s >>> total read requests: 2417 (of these ~2042 are 512KB reads). >>> total write requests: 2701 (of these ~2034 requests are written in 512KB). >> >> IMO, it only impact sequential read performance in a large file which may be >> fragmented during multi-thread writing. >> >> In android environment, mostly, the large file should be cold type, such as >> apk, >> mp3, rmvb, jpeg..., so I think we only need to serialize writepages() for >> cold >> data area writer. >> >> So how about adding a mount option to serialize writepage() for different >> type >> of log, e.g. in android, using serialize=4; by default, using serialize=7 >> HOT_DATA 1 >> WARM_DATA 2 >> COLD_DATA 4 > > Well, I don't think we need to give too many mount options for this fragmented > case. How about doing this for the large files only like this?
Thread A write 512 pages Thread B write 8 pages - writepages() - mutex_lock(&sbi->writepages); - writepage(); ... - writepages() - writepage() .... - writepage(); ... - mutex_unlock(&sbi->writepages); Above case will also cause fragmentation since we didn't serialize all concurrent IO with the lock. Do we need to consider such case? Thanks, > >>From 4fea0b6e4da8512a72dd52afc7a51beb35966ad9 Mon Sep 17 00:00:00 2001 > From: Jaegeuk Kim <jaeg...@kernel.org> > Date: Thu, 9 Aug 2018 17:53:34 -0700 > Subject: [PATCH] f2fs: fix performance issue observed with multi-thread > sequential read > > This reverts the commit - "b93f771 - f2fs: remove writepages lock" > to fix the drop in sequential read throughput. > > Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L > device: UFS > > Before - > read throughput: 185 MB/s > total read requests: 85177 (of these ~80000 are 4KB size requests). > total write requests: 2546 (of these ~2208 requests are written in 512KB). > > After - > read throughput: 758 MB/s > total read requests: 2417 (of these ~2042 are 512KB reads). > total write requests: 2701 (of these ~2034 requests are written in 512KB). > > Signed-off-by: Sahitya Tummala <stumm...@codeaurora.org> > Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > --- > Documentation/ABI/testing/sysfs-fs-f2fs | 8 ++++++++ > fs/f2fs/data.c | 10 ++++++++++ > fs/f2fs/f2fs.h | 2 ++ > fs/f2fs/segment.c | 1 + > fs/f2fs/super.c | 1 + > fs/f2fs/sysfs.c | 2 ++ > 6 files changed, 24 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs > b/Documentation/ABI/testing/sysfs-fs-f2fs > index 9b0123388f18..94a24aedcdb2 100644 > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > @@ -51,6 +51,14 @@ Description: > Controls the dirty page count condition for the in-place-update > policies. > > +What: /sys/fs/f2fs/<disk>/min_seq_blocks > +Date: August 2018 > +Contact: "Jaegeuk Kim" <jaeg...@kernel.org> > +Description: > + Controls the dirty page count condition for batched sequential > + writes in ->writepages. > + > + > What: /sys/fs/f2fs/<disk>/min_hot_blocks > Date: March 2017 > Contact: "Jaegeuk Kim" <jaeg...@kernel.org> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 45f043ee48bd..f09231b1cc74 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2132,6 +2132,7 @@ static int __f2fs_write_data_pages(struct address_space > *mapping, > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > struct blk_plug plug; > int ret; > + bool locked = false; > > /* deal with chardevs and other special file */ > if (!mapping->a_ops->writepage) > @@ -2162,10 +2163,19 @@ static int __f2fs_write_data_pages(struct > address_space *mapping, > else if (atomic_read(&sbi->wb_sync_req[DATA])) > goto skip_write; > > + if (!S_ISDIR(inode->i_mode) && > + get_dirty_pages(inode) <= SM_I(sbi)->min_seq_blocks) { > + mutex_lock(&sbi->writepages); > + locked = true; > + } > + > blk_start_plug(&plug); > ret = f2fs_write_cache_pages(mapping, wbc, io_type); > blk_finish_plug(&plug); > > + if (locked) > + mutex_unlock(&sbi->writepages); > + > if (wbc->sync_mode == WB_SYNC_ALL) > atomic_dec(&sbi->wb_sync_req[DATA]); > /* > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 375aa9f30cfa..098bdedc28bf 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -913,6 +913,7 @@ struct f2fs_sm_info { > unsigned int ipu_policy; /* in-place-update policy */ > unsigned int min_ipu_util; /* in-place-update threshold */ > unsigned int min_fsync_blocks; /* threshold for fsync */ > + unsigned int min_seq_blocks; /* threshold for sequential blocks */ > unsigned int min_hot_blocks; /* threshold for hot block allocation */ > unsigned int min_ssr_sections; /* threshold to trigger SSR allocation > */ > > @@ -1133,6 +1134,7 @@ struct f2fs_sb_info { > struct rw_semaphore sb_lock; /* lock for raw super block */ > int valid_super_block; /* valid super block no */ > unsigned long s_flag; /* flags for sbi */ > + struct mutex writepages; /* mutex for writepages() */ > > #ifdef CONFIG_BLK_DEV_ZONED > unsigned int blocks_per_blkz; /* F2FS blocks per zone */ > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 63fc647f9ac2..ffea2d1303bd 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -4131,6 +4131,7 @@ int f2fs_build_segment_manager(struct f2fs_sb_info *sbi) > sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC; > sm_info->min_ipu_util = DEF_MIN_IPU_UTIL; > sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS; > + sm_info->min_seq_blocks = sbi->blocks_per_seg * sbi->segs_per_sec; > sm_info->min_hot_blocks = DEF_MIN_HOT_BLOCKS; > sm_info->min_ssr_sections = reserved_sections(sbi); > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index be41dbd7b261..53d70b64fea1 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -2842,6 +2842,7 @@ static int f2fs_fill_super(struct super_block *sb, void > *data, int silent) > /* init f2fs-specific super block info */ > sbi->valid_super_block = valid_super_block; > mutex_init(&sbi->gc_mutex); > + mutex_init(&sbi->writepages); > mutex_init(&sbi->cp_mutex); > init_rwsem(&sbi->node_write); > init_rwsem(&sbi->node_change); > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c > index cd2e030e47b8..81c0e5337443 100644 > --- a/fs/f2fs/sysfs.c > +++ b/fs/f2fs/sysfs.c > @@ -397,6 +397,7 @@ F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, > batched_trim_sections, trim_sections); > F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy); > F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util); > F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks); > +F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_seq_blocks, min_seq_blocks); > F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_hot_blocks, min_hot_blocks); > F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ssr_sections, min_ssr_sections); > F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh); > @@ -449,6 +450,7 @@ static struct attribute *f2fs_attrs[] = { > ATTR_LIST(ipu_policy), > ATTR_LIST(min_ipu_util), > ATTR_LIST(min_fsync_blocks), > + ATTR_LIST(min_seq_blocks), > ATTR_LIST(min_hot_blocks), > ATTR_LIST(min_ssr_sections), > ATTR_LIST(max_victim_search), > ------------------------------------------------------------------------------ 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 Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel