[0/2] Add BLK_FEAT_READ_SYNCHRONOUS and SWP_READ_SYNCHRONOUS_IO

Message

Qun-Wei Lin Sept. 19, 2024, 11:29 a.m. UTC

This patchset introduces 2 new feature flags, BLK_FEAT_READ_SYNCHRONOUS and
SWP_READ_SYNCHRONOUS_IO.

These changes are motivated by the need to better accommodate certain swap
devices that support synchronous read operations but asynchronous write
operations.

The existing BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO flags are not
sufficient for these devices, as they enforce synchronous behavior for both
read and write operations.

Patch 1:
- introduce BLK_FEAT_READ_SYNCHRONOUS

Patch 2:
- introduce SWP_READ_SYNCHRONOUS_IO

Qun-Wei Lin (2):
  block: add BLK_FEAT_READ_SYNCHRONOUS feature for synchronous read
  mm, swap: introduce SWP_READ_SYNCHRONOUS_IO

 include/linux/blkdev.h |  8 ++++++++
 include/linux/swap.h   | 31 ++++++++++++++++---------------
 mm/memory.c            |  3 ++-
 mm/page_io.c           |  2 +-
 mm/swapfile.c          |  3 +++
 5 files changed, 30 insertions(+), 17 deletions(-)

Comments

Christoph Hellwig Sept. 19, 2024, 11:37 a.m. UTC | #1

Well, you're not actually setting your new flags anywhere, which -
as you might know - is an reson for an insta-NAK.