Hi Jens,
A feature that is missing from the Linux kernel for storage devices that
support I/O priorities is to set the I/O priority in requests involving page
cache writeback. Since the identity of the process that triggers page cache
writeback is not known in the writeback code, the priority set by ioprio_set()
is ignored. However, an I/O cgroup is associated with writeback requests
by certain filesystems. Hence this patch series that implements the following
changes for the mq-deadline scheduler:
* Make the I/O priority configurable per I/O cgroup.
* Change the I/O priority of requests to the lower of (request I/O priority,
cgroup I/O priority).
* Introduce one queue per I/O priority in the mq-deadline scheduler.
Please consider this patch series for kernel v5.14.
Thanks,
Bart.
Bart Van Assche (9):
block/mq-deadline: Add several comments
block/mq-deadline: Add two lockdep_assert_held() statements
block/mq-deadline: Remove two local variables
block/mq-deadline: Rename dd_init_queue() and dd_exit_queue()
block/mq-deadline: Improve compile-time argument checking
block/mq-deadline: Reduce the read expiry time for non-rotational
media
block/mq-deadline: Reserve 25% of tags for synchronous requests
block/mq-deadline: Add I/O priority support
block/mq-deadline: Add cgroup support
block/Kconfig.iosched | 6 +
block/Makefile | 1 +
block/mq-deadline-cgroup.c | 206 +++++++++++++++
block/mq-deadline-cgroup.h | 73 ++++++
block/mq-deadline.c | 524 +++++++++++++++++++++++++++++--------
5 files changed, 695 insertions(+), 115 deletions(-)
create mode 100644 block/mq-deadline-cgroup.c
create mode 100644 block/mq-deadline-cgroup.h
