40 lines
1.6 KiB
Text
40 lines
1.6 KiB
Text
# ktune sysctl settings for rhel6 servers, 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
|
|
|
|
# TODO: this bits need comment
|
|
kernel.sched_latency_ns = 80000000
|
|
kernel.sched_features = 15834234
|
|
kernel.sched_tunable_scaling = 0
|
|
|
|
# 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
|