On Mon, Sep 12, 2022 at 8:28 PM Stefan Roesch <shr@xxxxxx> wrote: > > This patch series adds support for async buffered writes when using both > btrfs and io-uring. Currently io-uring only supports buffered writes (for btrfs) > in the slow path, by processing them in the io workers. With this patch series > it is now possible to support buffered writes in the fast path. To be able to use > the fast path, the required pages must be in the page cache, the required locks > in btrfs can be granted immediately and no additional blocks need to be read > form disk. > > This patch series makes use of the changes that have been introduced by a > previous patch series: "io-uring/xfs: support async buffered writes" > > Performance results: > > The new patch improves throughput by over two times (compared to the exiting > behavior, where buffered writes are processed by an io-worker process) and also > the latency is considerably reduced. Detailled results are part of the changelog > of the first commit. Not in the first, but in the last commit instead. Looks fine to me now, thanks. Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx> > > > BTRFS changes: > -Add option for NOWAIT IOCB's to tell that searches do not wait on locks. This > adds the nowait option to btrfs_path. > -For NOWAIT buffered writes on PREALLOC or NOCOW extents tell can_nocow_extent() > that we don't want to wait on any locks or metadata IO. > -Support no_flush reservations for nowait buffered writes. > -Add btrfs_try_lock_ordered_range() function. > -Add nowait flag to btrfs_check_nocow_lock() to use it in write code path. > -Add nowait parameter to prepare_pages() function. > -Plumb nowait through the write code path. > -Enable nowait buffered writes. > > > Testing: > This patch has been tested with xfstests, fsx, fio. xfstests shows no new > diffs compared to running without the patch series. > > > Changes: > > V3: > - Updated changelog of "btrfs: implement a nowait option for tree searches" > to say -EAGAIN. > - Use bool return value in signature of btrfs_try_lock_ordered_range > - Renamed variable tmp to can_nocow in btrfs_buffered_write > - Fixed coding style in get_prepare_fgp_flags > - Set pages[i] to NULL in error code path of lock_and_cleanup_extent_if_need() > - Added const in definition of "bool nowait" > - Removed unlikely from btrfs_buffered_write > - Rephrased changelog for "btrfs: add assert to search functions" and used > asserts instead of warnings > - Explained why enocded writes are not supported in the changelog > - Moved performance results to changelog of first commit > > V2: > - Replace EWOULDBLOCK with EAGAIN. In Version 1 it was not used consistently > - Export function balance_dirty_pages_ratelimited_flags() > - Add asserts/warnings for search functions when nowait is set, but we don't > expect that they are invoked with nowait set. > > > > Josef Bacik (5): > btrfs: implement a nowait option for tree searches > btrfs: make can_nocow_extent nowait compatible > btrfs: add the ability to use NO_FLUSH for data reservations > btrfs: add btrfs_try_lock_ordered_range > btrfs: make btrfs_check_nocow_lock nowait compatible > > Stefan Roesch (7): > mm: export balance_dirty_pages_ratelimited_flags() > btrfs: make prepare_pages nowait compatible > btrfs: make lock_and_cleanup_extent_if_need nowait compatible > btrfs: plumb NOWAIT through the write path > btrfs: make balance_dirty_pages nowait compatible > btrfs: assert nowait mode is not used for some btree search functions > btrfs: enable nowait async buffered writes > > fs/btrfs/block-group.c | 2 +- > fs/btrfs/ctree.c | 43 ++++++++++++- > fs/btrfs/ctree.h | 8 ++- > fs/btrfs/delalloc-space.c | 13 +++- > fs/btrfs/delalloc-space.h | 3 +- > fs/btrfs/extent-tree.c | 5 ++ > fs/btrfs/file-item.c | 4 +- > fs/btrfs/file.c | 124 ++++++++++++++++++++++++++++---------- > fs/btrfs/inode.c | 22 ++++--- > fs/btrfs/locking.c | 23 +++++++ > fs/btrfs/locking.h | 1 + > fs/btrfs/ordered-data.c | 28 +++++++++ > fs/btrfs/ordered-data.h | 1 + > fs/btrfs/relocation.c | 2 +- > fs/btrfs/scrub.c | 4 +- > fs/btrfs/space-info.c | 3 +- > fs/btrfs/tree-log.c | 6 +- > mm/page-writeback.c | 1 + > 18 files changed, 234 insertions(+), 59 deletions(-) > > > base-commit: 80e78fcce86de0288793a0ef0f6acf37656ee4cf > -- > 2.30.2 >
