From 927529c1ccf0e917b9bd5a46adbdfb86145e3d2d Mon Sep 17 00:00:00 2001 From: Jarod Wilson Date: Wed, 14 Jul 2010 11:21:30 -0400 Subject: [PATCH] further throughput-performance profile tweaks - don't set pid_max by default, as it can be highly dependent on cpu count (and architecture, to some extent) - add commented out vm.dirty_background_ratio param, which we may or may not set sometime in the future, but its also there now for people to enable w/relative ease. Signed-off-by: Jarod Wilson --- tune-profiles/throughput-performance/sysctl.ktune | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/tune-profiles/throughput-performance/sysctl.ktune b/tune-profiles/throughput-performance/sysctl.ktune index 8c3c439..eb1705c 100644 --- a/tune-profiles/throughput-performance/sysctl.ktune +++ b/tune-profiles/throughput-performance/sysctl.ktune @@ -16,9 +16,20 @@ kernel.sched_wakeup_granularity_ns = 15000000 # 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. -kernel.pid_max = 131072 +# +# 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