From 4ce02c67972211be488408c275c8fbf19faf29b3 Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Mon, 10 Jul 2023 14:12:43 -0700 Subject: iomap: Add per-block dirty state tracking to improve performance When filesystem blocksize is less than folio size (either with mapping_large_folio_support() or with blocksize < pagesize) and when the folio is uptodate in pagecache, then even a byte write can cause an entire folio to be written to disk during writeback. This happens because we currently don't have a mechanism to track per-block dirty state within struct iomap_folio_state. We currently only track uptodate state. This patch implements support for tracking per-block dirty state in iomap_folio_state->state bitmap. This should help improve the filesystem write performance and help reduce write amplification. Performance testing of below fio workload reveals ~16x performance improvement using nvme with XFS (4k blocksize) on Power (64K pagesize) FIO reported write bw scores improved from around ~28 MBps to ~452 MBps. 1. [global] ioengine=psync rw=randwrite overwrite=1 pre_read=1 direct=0 bs=4k size=1G dir=./ numjobs=8 fdatasync=1 runtime=60 iodepth=64 group_reporting=1 [fio-run] 2. Also our internal performance team reported that this patch improves their database workload performance by around ~83% (with XFS on Power) Reported-by: Aravinda Herle Reported-by: Brian Foster Signed-off-by: Ritesh Harjani (IBM) Reviewed-by: Darrick J. Wong --- include/linux/iomap.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 80facb9c9e5b..fdc6e64f49d6 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -264,6 +264,7 @@ bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count); struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len); bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len); +bool iomap_dirty_folio(struct address_space *mapping, struct folio *folio); int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, const struct iomap_ops *ops); int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, -- cgit v1.2.3