Subversion Repositories configs

# ktune sysctl settings for rhel6 servers with enterprise-class

# storage, maximizing i/o throughput

#

# Minimal preemption granularity for CPU-bound tasks:

# (default: 1 msec#  (1 + ilog(ncpus)), units: nanoseconds)

kernel.sched_min_granularity_ns = 10000000

# SCHED_OTHER wake-up granularity.

# (default: 1 msec#  (1 + ilog(ncpus)), units: nanoseconds)

#

# This option delays the preemption effects of decoupled workloads

# and reduces their over-scheduling. Synchronous workloads will still

# have immediate wakeup/sleep latencies.

kernel.sched_wakeup_granularity_ns = 15000000

# Filesystem I/O is usually much more efficient than swapping, so try to keep

# swapping low.  It's usually safe to go even lower than this on systems with

# server-grade storage.

vm.swappiness = 30

# If a workload mostly uses anonymous memory and it hits this limit, the entire

# working set is buffered for I/O, and any more write buffering would require

# swapping, so it's time to throttle writes until I/O can catch up.  Workloads

# that mostly use file mappings may be able to use even higher values.

#

# The generator of dirty data starts writeback at this percentage (system default

# is 20%)

vm.dirty_ratio = 40

# Start background writeback (via writeback threads) at this percentage (system

# default is 10%)

#vm.dirty_background_ratio = 15

# PID allocation wrap value.  When the kernel's next PID value

# reaches this value, it wraps back to a minimum PID value.

# PIDs of value pid_max or larger are not allocated.

#

# A suggested value for pid_max is 1024 * <# of cpu cores/threads in system>

# e.g., a box with 32 cpus, the default of 32768 is reasonable, for 64 cpus,

# 65536, for 4096 cpus, 4194304 (which is the upper limit possible).

#kernel.pid_max = 65536