Ritesh, Am Mo., 5. Juni 2023 um 03:33 Uhr schrieb Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>: > Hello All, > > Please find PATCHv6 which adds per-block dirty tracking to iomap. > As discussed earlier this is required to improve write performance and reduce > write amplification for cases where either blocksize is less than pagesize (such > as Power platform with 64k pagesize) or when we have a large folio (such as xfs > which currently supports large folio). > > RFCv5 -> PATCHv6: > ================= > 1. Addresses review comments from Brian, Christoph and Matthew. > @Christoph: > - I have renamed the higher level functions such as iop_alloc/iop_free() to > iomap_iop_alloc/free() in v6. > - As for the low level bitmap accessor functions I couldn't find any better > naming then iop_test_/set/clear_**. I could have gone for > iomap_iop__test/set/clear/_** or iomap__iop_test/set/clear_**, but > I wasn't convinced with either of above as it also increases function > name. > Besides iop_test/set_clear_ accessors functions for uptodate and dirty > status tracking make sense as we are sure we have a valid iop in such > cases. Please do let me know if this looks ok to you. > 2. I tried testing gfs2 (initially with no patches) with xfstests. But I always ended up > in some or the other deadlock (I couldn't spend any time debugging that). > I also ran it with -x log, but still it was always failing for me. > @Andreas: > - could you please suggest how can I test gfs2 with these patches. I see gfs2 > can have a smaller blocksize and it uses iomap buffered io path. It will be > good if we can get these patches tested on it too. here's a minimal list of tests we're running automatically on a daily basis: https://gitlab.com/redhat/centos-stream/tests/kernel/kernel-tests/-/blob/main/filesystems/xfs/xfstests/RUNTESTS.gfs2 Please note that function inode_to_wb() in <linux/backing-dev.h> includes some asserts that are active when CONFIG_LOCKDEP is enabled. Those asserts will cause every single fstest to fail. So either disable CONFIG_LOCKDEP or remove the asserts in inode_to_wb() for now. Thanks, Andreas > 3. I can now say I have run some good amount of fstests on these patches on > these platforms and I haven't found any new failure in my testing so far. > arm64 (64k pagesize): with 4k -g quick > Power: with 4k -g auto > x86: 1k, 4k with -g auto and adv_auto > > From my testing so far these patches looks stable to me and if this looks good > to reviewers as well, do you think this can be queued to linux-next for wider > testing? > > Performance numbers copied from last patch commit message > ================================================== > 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. <test_randwrite.fio> > [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) > > Ritesh Harjani (IBM) (5): > iomap: Rename iomap_page_create/release() to iomap_iop_alloc/free() > iomap: Move folio_detach_private() in iomap_iop_free() to the end > iomap: Refactor some iop related accessor functions > iomap: Allocate iop in ->write_begin() early > iomap: Add per-block dirty state tracking to improve performance > > fs/gfs2/aops.c | 2 +- > fs/iomap/buffered-io.c | 309 ++++++++++++++++++++++++++++++----------- > fs/xfs/xfs_aops.c | 2 +- > fs/zonefs/file.c | 2 +- > include/linux/iomap.h | 1 + > 5 files changed, 235 insertions(+), 81 deletions(-) > > -- > 2.40.1 >
