Hi all, Here's v2 of the performance improvement for zero range. This is the same general idea as v1, but a rework to lift the special handling of zeroed mappings into the caller and open-code the two approaches from there. The idea is that for partial eof zeroing, we can check whether the folio for the block is already dirty in pagecache and if so, zero it directly. Otherwise, fall back into existing behavior for the remainder of the range. This brings stress-ng metamix performance back in my local tests and survives fstests without seeing any regressions. Thoughts, reviews, flames appreciated. Brian v2: - Added patch 1 to lift zeroed mapping handling code into caller. - Split unaligned start range handling at the top level. - Retain existing conditional flush behavior (vs. unconditional flush) for the remaining range. v1: https://lore.kernel.org/linux-fsdevel/20241023143029.11275-1-bfoster@xxxxxxxxxx/ Brian Foster (2): iomap: lift zeroed mapping handling into iomap_zero_range() iomap: elide flush from partial eof zero range fs/iomap/buffered-io.c | 99 ++++++++++++++++++++++++------------------ 1 file changed, 56 insertions(+), 43 deletions(-) -- 2.46.2
