From 754a1227925ca988797de9d56b16c7c1616418c6 Mon Sep 17 00:00:00 2001 From: Patrick Bellasi Date: Mon, 22 Jun 2015 18:11:44 +0100 Subject: sched/tune: add sysctl interface to define a boost value The current (CFS) scheduler implementation does not allow "to boost" tasks performance by running them at a higher OPP compared to the minimum required to meet their workload demands. To support tasks performance boosting the scheduler should provide a "knob" which allows to tune how much the system is going to be optimised for energy efficiency vs performance. This patch is the first of a series which provides a simple interface to define a tuning knob. One system-wide "boost" tunable is exposed via: /proc/sys/kernel/sched_cfs_boost which can be configured in the range [0..100], to define a percentage where: - 0% boost requires to operate in "standard" mode by scheduling tasks at the minimum capacities required by the workload demand - 100% boost requires to push at maximum the task performances, "regardless" of the incurred energy consumption A boost value in between these two boundaries is used to bias the power/performance trade-off, the higher the boost value the more the scheduler is biased toward performance boosting instead of energy efficiency. Change-Id: I59a41725e2d8f9238a61dfb0c909071b53560fc0 cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Patrick Bellasi Git-commit: 63c8fad2b06805ef88f1220551289f0a3c3529f1 Git-repo: https://source.codeaurora.org/quic/la/kernel/msm-4.4 Signed-off-by: Vikram Mulukutla --- include/linux/sched/sysctl.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include') diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 861f715a673d..9fe71c774543 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -121,6 +121,22 @@ extern int sysctl_sched_rt_runtime; extern unsigned int sysctl_sched_cfs_bandwidth_slice; #endif +#ifdef CONFIG_SCHED_TUNE +extern unsigned int sysctl_sched_cfs_boost; +int sysctl_sched_cfs_boost_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, + loff_t *ppos); +static inline unsigned int get_sysctl_sched_cfs_boost(void) +{ + return sysctl_sched_cfs_boost; +} +#else +static inline unsigned int get_sysctl_sched_cfs_boost(void) +{ + return 0; +} +#endif + #ifdef CONFIG_SCHED_AUTOGROUP extern unsigned int sysctl_sched_autogroup_enabled; #endif -- cgit v1.2.3