> On 9 Jan 2019, at 16.30, Kanchan Joshi wrote: > > Towards supporing write-hints/streams for filesystem journal. > > Here is the v1 patch for background - > https://marc.info/?l=linux-fsdevel&m=154444637519020&w=2 > > Changes since v1: > - introduce four more hints for in-kernel use, as recommended by Dave chinner > & Jens axboe. This isolates kernel-mode hints from user-mode ones. > - remove mount-option to specify write-hint, as recommended by Jan kara & > Dave chinner. Rather, FS always sets write-hint for journal. This gets ignored > if device does not support stream. > - Removed code-redundancy for write_dirty_buffer (Jan kara's review comment) > > > Kanchan Joshi (4): > block: Increase count of supported write-hints > fs: introduce four macros for in-kernel hints > fs: introduce APIs to enable sending write-hint with buffer-head > fs/ext4,jbd2: add support for passing write-hint with journal. > > fs/buffer.c | 18 ++++++++++++++++-- > fs/ext4/super.c | 2 ++ > fs/jbd2/commit.c | 11 +++++++---- > fs/jbd2/journal.c | 3 ++- > fs/jbd2/revoke.c | 3 ++- > include/linux/blkdev.h | 5 ++++- > include/linux/buffer_head.h | 3 +++ > include/linux/fs.h | 5 +++++ > include/linux/jbd2.h | 8 ++++++++ > 9 files changed, 49 insertions(+), 9 deletions(-) > > -- > 2.7.4 Worth sharing the paper where you describe the design and the numbers you collected [1]. Also, addressing Dave's comment on stream support, it points to a Samsung drive supporting streams (PM963). In this context, you should verify in V3 that we are at least passing xfstests and blktests with these changes. [1] https://www.usenix.org/system/files/conference/fast18/fast18-rho.pdf Javier