# {{ ansible_managed }}
# Fedora's /usr/lib/udev/rules.d/60-block-scheduler.rules picks bfq for every
# rotational=0 SATA disk. bfq is a fairness scheduler built for spinning disks
# and desktop interactivity: it costs real CPU per request and, with 26
# containers plus two CI runners all writing at once, it lets reads queue
# behind write bursts. That is the shape of the stalls seen here -- I/O
# pressure spiking to 76% while the CPU sat nearly idle.
#
# mq-deadline instead of none: this is a SATA SSD with a 32-deep NCBQ queue,
# not an NVMe device with its own deep queues, so the request merging and the
# read-expiry deadline are both worth having. The deadline is what stops reads
# starving behind a QLC write burst.
#
# bfq also hard-caps nr_requests at 64; mq-deadline allows a deeper queue,
# which is what lets concurrent container and CI I/O actually overlap.
ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="0", \
  ATTR{queue/scheduler}="{{ ssd_io_scheduler }}", \
  ATTR{queue/nr_requests}="{{ ssd_nr_requests }}"