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author | Linus Walleij <linus.walleij@linaro.org> | 2020-04-02 10:02:39 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-04-03 11:20:06 +0200 |
commit | 8fdcca8e254ad980d083a03c3c60d8225b320ffb (patch) | |
tree | 7f662445e4be8256ee08be76e31e95fc02969a31 /kernel/trace/trace_stack.c | |
parent | a00ec3874e7d326ab2dffbed92faddf6a77a84e9 (diff) |
cpufreq: Select schedutil when using big.LITTLE
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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/trace/trace_stack.c')
0 files changed, 0 insertions, 0 deletions