| Message ID | 20230602222445.2284892-1-willy@infradead.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Create large folios in iomap buffered write path | expand |
Hi, > Commit ebb7fb1557b1 limited the length of ioend chains to 4096 entries > to improve worst-case latency. Unfortunately, this had the effect of > limiting the performance of: > > fio -name write-bandwidth -rw=write -bs=1024Ki -size=32Gi -runtime=30 \ > -iodepth 1 -ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 \ > -numjobs=4 -directory=/mnt/test > > The problem ends up being lock contention on the i_pages spinlock as we > clear the writeback bit on each folio (and propagate that up through > the tree). By using larger folios, we decrease the number of folios > to be processed by a factor of 256 for this benchmark, eliminating the > lock contention. > > It's also the right thing to do. This is a project that has been on > the back burner for years, it just hasn't been important enough to do > before now. > > I think it's probably best if this goes through the iomap tree since > the changes outside iomap are either to the page cache or they're > trivial. > > v2: > - Fix misplaced semicolon > - Rename fgp_order to fgp_set_order > - Rename FGP_ORDER to FGP_GET_ORDER > - Add fgp_t > - Update the documentation for ->release_folio > - Fix iomap_invalidate_folio() > - Update iomap_release_folio() It works well based on 6.4-rc4 here. fio write bandwidth: about 8000MiB/s And I tried to backport it to 6.1.y, it works well too. 1) 8 patches are selected as depency. d7b64041164c :Dave Chinner: iomap: write iomap validity checks 7a70a5085ed0 :Andreas Gruenbacher: iomap: Add __iomap_put_folio helper 80baab88bb93 :Andreas Gruenbacher: iomap/gfs2: Unlock and put folio in page_done handler 40405dddd98a :Andreas Gruenbacher: iomap: Rename page_done handler to put_folio 98321b5139f9 :Andreas Gruenbacher: iomap: Add iomap_get_folio helper 9060bc4d3aca :Andreas Gruenbacher: iomap/gfs2: Get page in page_prepare handler 07c22b56685d :Andreas Gruenbacher: iomap: Add __iomap_get_folio helper c82abc239464 :Andreas Gruenbacher: iomap: Rename page_prepare handler to get_folio 2) patch 4/5/6 are rebased (see attachment files) better backport are welcome. Best Regards Wang Yugui (wangyugui@e16-tech.com) 2023/06/04 > Matthew Wilcox (Oracle) (7): > iomap: Remove large folio handling in iomap_invalidate_folio() > doc: Correct the description of ->release_folio > iomap: Remove unnecessary test from iomap_release_folio() > filemap: Add fgp_t typedef > filemap: Allow __filemap_get_folio to allocate large folios > iomap: Create large folios in the buffered write path > iomap: Copy larger chunks from userspace > > Documentation/filesystems/locking.rst | 14 ++++-- > fs/btrfs/file.c | 6 +-- > fs/f2fs/compress.c | 2 +- > fs/f2fs/f2fs.h | 2 +- > fs/gfs2/bmap.c | 2 +- > fs/iomap/buffered-io.c | 43 ++++++++-------- > include/linux/iomap.h | 2 +- > include/linux/pagemap.h | 71 ++++++++++++++++++++++----- > mm/filemap.c | 61 ++++++++++++----------- > mm/folio-compat.c | 2 +- > mm/readahead.c | 13 ----- > 11 files changed, 130 insertions(+), 88 deletions(-) > > -- > 2.39.2
Commit ebb7fb1557b1 limited the length of ioend chains to 4096 entries to improve worst-case latency. Unfortunately, this had the effect of limiting the performance of: fio -name write-bandwidth -rw=write -bs=1024Ki -size=32Gi -runtime=30 \ -iodepth 1 -ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 \ -numjobs=4 -directory=/mnt/test The problem ends up being lock contention on the i_pages spinlock as we clear the writeback bit on each folio (and propagate that up through the tree). By using larger folios, we decrease the number of folios to be processed by a factor of 256 for this benchmark, eliminating the lock contention. It's also the right thing to do. This is a project that has been on the back burner for years, it just hasn't been important enough to do before now. I think it's probably best if this goes through the iomap tree since the changes outside iomap are either to the page cache or they're trivial. v2: - Fix misplaced semicolon - Rename fgp_order to fgp_set_order - Rename FGP_ORDER to FGP_GET_ORDER - Add fgp_t - Update the documentation for ->release_folio - Fix iomap_invalidate_folio() - Update iomap_release_folio() Matthew Wilcox (Oracle) (7): iomap: Remove large folio handling in iomap_invalidate_folio() doc: Correct the description of ->release_folio iomap: Remove unnecessary test from iomap_release_folio() filemap: Add fgp_t typedef filemap: Allow __filemap_get_folio to allocate large folios iomap: Create large folios in the buffered write path iomap: Copy larger chunks from userspace Documentation/filesystems/locking.rst | 14 ++++-- fs/btrfs/file.c | 6 +-- fs/f2fs/compress.c | 2 +- fs/f2fs/f2fs.h | 2 +- fs/gfs2/bmap.c | 2 +- fs/iomap/buffered-io.c | 43 ++++++++-------- include/linux/iomap.h | 2 +- include/linux/pagemap.h | 71 ++++++++++++++++++++++----- mm/filemap.c | 61 ++++++++++++----------- mm/folio-compat.c | 2 +- mm/readahead.c | 13 ----- 11 files changed, 130 insertions(+), 88 deletions(-)