# # tuned configuration # [main] summary=Optimize for deterministic performance at the cost of increased power consumption [cpu] force_latency=1 governor=performance energy_perf_bias=performance min_perf_pct=100 [sysctl] # 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 # 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=10 # Start background writeback (via writeback threads) at this percentage (system # default is 10%) vm.dirty_background_ratio=3 # The swappiness parameter controls the tendency of the kernel to move # processes out of physical memory and onto the swap disk. # 0 tells the kernel to avoid swapping processes out of physical memory # for as long as possible # 100 tells the kernel to aggressively swap processes out of physical memory # and move them to swap cache vm.swappiness=10 # The total time the scheduler will consider a migrated process # "cache hot" and thus less likely to be re-migrated # (system default is 500000, i.e. 0.5 ms) kernel.sched_migration_cost_ns=5000000