| Message ID | 20200402080239.7471-1-linus.walleij@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | cpufreq: Select schedutil when using big.LITTLE | expand |
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index bff5295016ae..873aefd96cf2 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -36,6 +36,7 @@ config CPU_FREQ_STAT choice prompt "Default CPUFreq governor" + default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ default CPU_FREQ_DEFAULT_GOV_PERFORMANCE help
When we are using a system with big.LITTLE HMP configuration, we need to use EAS to schedule the system. As can be seen from kernel/sched/topology.c: "EAS can be used on a root domain if it meets all the following conditions: 1. an Energy Model (EM) is available; 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy. 3. no SMT is detected. 4. the EM complexity is low enough to keep scheduling overheads low; 5. schedutil is driving the frequency of all CPUs of the rd;" This means that at the very least, schedutil needs to be available as a scheduling policy for EAS to work on these systems. Make this explicit by defaulting to the schedutil governor if BIG_LITTLE is selected. Currently users of the TC2 board (like me) has to figure these dependencies out themselves and it is not helpful. Suggested-by: Arnd Bergmann <arnd@arndb.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/cpufreq/Kconfig | 1 + 1 file changed, 1 insertion(+)