[RFC PATCH v4 32/34] ext4: enable large folio for regular file with iomap buffered IO path

Zhang Yi
2024-04-10T15:11:53Z

Since we've convert buffered IO path to iomap for regular files, we can
enable large foilo together, that should be able to bring a lot of
performance gains for large IO. These are fio tests with psync on Intel
Xeon Gold 6240 CPU with 400GB system ram, 200GB ramdisk and 1TB nvme ssd
disk.

buffer read:

buffer head iomap + large folio
type bs IOPS BW(MiB/s) IOPS BW(MiB/s)
----------------------------------------------------
hole 64K 45.1k 2820 78.1k 4879
hole 1M 2744 2744 4890 4891
ramdisk 64K 29.6k 1848 44.0k 2747
ramdisk 1M 1994 1995 2809 2809
nvme 64K 19.3k 1208 24.3k 1517
nvme 1M 1694 1694 2256 2256

buffer write:

buffer head iomap + large folio
type Overwrite Sync Writeback bs IOPS BW IOPS BW
-------------------------------------------------------------
cache N N N 64K 30.8k 1928 80.1k 5005
cache N N N 1M 1963 1963 5641 5642
cache Y N N 64K 33.0k 2063 80.8k 5051
cache Y N N 1M 2103 2103 5588 5589
ramdisk N N Y 64K 22.4k 1399 64.8k 4050
ramdisk N N Y 1M 1670 1670 4559 4560
ramdisk N Y N 64K 5834 365 10.1k 629
ramdisk N Y N 1M 1011 1011 2064 2064
ramdisk Y N Y 64K 29.2k 1827 73.6k 4597
ramdisk Y N Y 1M 1837 1837 4985 4985
ramdisk Y Y N 64K 17.7k 1109 33.7k 2105
ramdisk Y Y N 1M 1128 1129 1790 1791
nvme N N Y 64K 21.5k 1343 57.4k 3590
nvme N N Y 1M 1308 1308 3664 3664
nvme N Y N 64K 5962 373 8598 537
nvme N Y N 1M 676 677 1417 1418
nvme Y N Y 64K 26.7k 1670 56.8k 3547
nvme Y N Y 1M 1745 1746 3586 3586
nvme Y Y N 64K 13.0k 813 21.0k 1311
nvme Y Y N 1M 683 683 1368 1369

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
fs/ext4/ialloc.c | 4 +++-
fs/ext4/inode.c | 4 +++-
fs/ext4/move_extent.c | 1 +
3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 956b9d69c559..5a22fe5aa46b 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -1336,8 +1336,10 @@ struct inode *__ext4_new_inode(struct mnt_idmap *idmap,
}
}

- if (ext4_should_use_buffered_iomap(inode))
+ if (ext4_should_use_buffered_iomap(inode)) {
ext4_set_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP);
+ mapping_set_large_folios(inode->i_mapping);
+ }

if (ext4_handle_valid(handle)) {
ei->i_sync_tid = handle->h_transaction->t_tid;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 624eac0cc705..1cb219d347af 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5400,8 +5400,10 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
if (ret)
goto bad_inode;

- if (ext4_should_use_buffered_iomap(inode))
+ if (ext4_should_use_buffered_iomap(inode)) {
ext4_set_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP);
+ mapping_set_large_folios(inode->i_mapping);
+ }

if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext4_file_inode_operations;
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 3db255385367..6722b39049cf 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -560,6 +560,7 @@ static int ext4_disable_buffered_iomap_aops(struct inode *inode)
truncate_inode_pages(inode->i_mapping, 0);

ext4_clear_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP);
+ mapping_clear_large_folios(inode->i_mapping);
ext4_set_aops(inode);
filemap_invalidate_unlock(inode->i_mapping);

--
2.39.2