From e850f5786cdd4d3e4f1157db8785de3e6ff77eab Mon Sep 17 00:00:00 2001 From: Riley Andrews Date: Mon, 20 Jul 2015 16:01:48 -0700 Subject: [PATCH] Disable scaling of the cfs tunables. The cfs tunables auto-scale with the number of active cpus by default. Given that the tunable settings are in device-independent code and it's not known how many cores are currently active when the init.rc file runs, the cfs tunables can vary pretty significantly across devices depending on the state at boot. Disable scaling of the the tunables so that we can get more consistent behavior of cfs across devices. If we want to do per-device tuning of these values, we can override what's written here in device specific files. Bug: 22634118 Change-Id: Id19b24ef819fef762521e75af55e6d4378cfc949 --- rootdir/init.rc | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/rootdir/init.rc b/rootdir/init.rc index 4e2335412..0ac669803 100644 --- a/rootdir/init.rc +++ b/rootdir/init.rc @@ -87,10 +87,17 @@ on init write /proc/sys/kernel/panic_on_oops 1 write /proc/sys/kernel/hung_task_timeout_secs 0 write /proc/cpu/alignment 4 + + # scheduler tunables + # Disable auto-scaling of scheduler tunables with hotplug. The tunables + # will vary across devices in unpredictable ways if allowed to scale with + # cpu cores. + write /proc/sys/kernel/sched_tunable_scaling 0 write /proc/sys/kernel/sched_latency_ns 10000000 write /proc/sys/kernel/sched_wakeup_granularity_ns 2000000 write /proc/sys/kernel/sched_compat_yield 1 write /proc/sys/kernel/sched_child_runs_first 0 + write /proc/sys/kernel/randomize_va_space 2 write /proc/sys/kernel/kptr_restrict 2 write /proc/sys/vm/mmap_min_addr 32768