# /etc/sysctl.d/60-ukrrs-vm.conf — ultix-streaming mixed-workload profile
# Measured-before values and rationale: ~/projects/ultix/REPORT.md §4.1.
# Deliberately NOT touched: swappiness(60), overcommit(0), vfs_cache_pressure,
# pid_max, somaxconn(4096), conntrack(262144), autogroup(1), page-cluster(3).

# Predictable writeback under ETL bursts (bytes-based, RAM-size independent).
# Night profile (ukrrs-daynight.sh) raises these to 2G/512M.
vm.dirty_background_bytes = 268435456
vm.dirty_bytes = 1073741824

# Survive bursty reclaim when compiles+ETL hit at once. 768M post-upgrade.
vm.min_free_kbytes = 393216

# Postgres AIO / io_uring era; 9 harness daemons + LSPs watching many repos.
fs.aio-max-nr = 1048576
fs.inotify.max_user_watches = 1048576
fs.inotify.max_user_instances = 512

# 9 accounts x long-lived provider streams + tailscale + docker NAT.
net.ipv4.ip_local_port_range = 10240 65535
net.ipv4.tcp_tw_reuse = 1

# LLM turns idle minutes between bursts on live sockets; large SSE/JSON.
net.ipv4.tcp_slow_start_after_idle = 0
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 131072 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
net.core.netdev_max_backlog = 8192

# BBR requires the module: staged modules-load.d/tcp_bbr.conf loads it.
# If bbr is unavailable, comment the last two lines out (cubic is fine).
net.ipv4.tcp_congestion_control = bbr
net.core.default_qdisc = fq