From 07e22949de7116dfac9098a46109c30776ead625 Mon Sep 17 00:00:00 2001 From: Patrick Bellasi Date: Fri, 26 Jun 2015 09:55:06 +0100 Subject: [PATCH] sched/fair: add boosted CPU usage The CPU usage signal is used by the scheduler as an estimation of the overall bandwidth currently allocated on a CPU. When SchedDVFS is in use, this signal affects the selection of the operating points (OPP) required to accommodate all the workload allocated in a CPU. A convenient way to boost the performance of tasks running on a CPU, which is also little intrusive, is to boost the CPU usage signal each time it is used to select an OPP. This patch introduces a new function: get_boosted_cpu_usage(cpu) to return a boosted value for the usage of a specified CPU. The margin added to the original usage is: 1. computed based on the "boosting strategy" in use 2. proportional to the system-wide boost value defined by provided user-space interface The boosted signal is used by SchedDVFS (transparently) each time it requires to get an estimation of the capacity required for a CPU. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Patrick Bellasi --- kernel/sched/fair.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1b6a57837433..eff548fae43e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4144,6 +4144,8 @@ static inline void hrtick_update(struct rq *rq) } #endif +static inline unsigned long boosted_cpu_util(int cpu); + static void update_capacity_of(int cpu) { unsigned long req_cap; @@ -4152,7 +4154,8 @@ static void update_capacity_of(int cpu) return; /* Convert scale-invariant capacity to cpu. */ - req_cap = cpu_util(cpu) * SCHED_CAPACITY_SCALE / capacity_orig_of(cpu); + req_cap = boosted_cpu_util(cpu); + req_cap = req_cap * SCHED_CAPACITY_SCALE / capacity_orig_of(cpu); set_cfs_cpu_capacity(cpu, true, req_cap); } @@ -5110,8 +5113,36 @@ schedtune_margin(unsigned long signal, unsigned long boost) return margin; } +static inline unsigned int +schedtune_cpu_margin(unsigned long util) +{ + unsigned int boost = get_sysctl_sched_cfs_boost(); + + if (boost == 0) + return 0; + + return schedtune_margin(util, boost); +} + +#else /* CONFIG_SCHED_TUNE */ + +static inline unsigned int +schedtune_cpu_margin(unsigned long util) +{ + return 0; +} + #endif /* CONFIG_SCHED_TUNE */ +static inline unsigned long +boosted_cpu_util(int cpu) +{ + unsigned long util = cpu_util(cpu); + unsigned long margin = schedtune_cpu_margin(util); + + return util + margin; +} + /* * find_idlest_group finds and returns the least busy CPU group within the * domain. -- 2.20.1