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authorDaniel Lezcano <daniel.lezcano@linaro.org>2019-11-16 14:16:12 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-11-20 11:32:55 +0100
commitc55b51a06b01d67a99457bb82a8c31081c7faa23 (patch)
treefdde096ae2e1d1b9c946b0a432ce5540f42d3350 /include/linux/cpu.h
parentcbda56d5fefcebc01448982a55836c88a825b34c (diff)
cpuidle: Allow idle injection to apply exit latency limit
In some cases it may be useful to specify an exit latency limit for the idle state to be used during CPU idle time injection. Instead of duplicating the information in struct cpuidle_device or propagating the latency limit in the call stack, replace the use_deepest_state field with forced_latency_limit_ns to represent that limit, so that the deepest idle state with exit latency within that limit is forced (i.e. no governors) when it is set. A zero exit latency limit for forced idle means to use governors in the usual way (analogous to use_deepest_state equal to "false" before this change). Additionally, add play_idle_precise() taking two arguments, the duration of forced idle and the idle state exit latency limit, both in nanoseconds, and redefine play_idle() as a wrapper around that new function. This change is preparatory, no functional impact is expected. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ rjw: Subject, changelog, cpuidle_use_deepest_state() kerneldoc, whitespace ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/cpu.h')
-rw-r--r--include/linux/cpu.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index d0633ebdaa9c..cc03a7848b63 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -179,7 +179,12 @@ void arch_cpu_idle_dead(void);
int cpu_report_state(int cpu);
int cpu_check_up_prepare(int cpu);
void cpu_set_state_online(int cpu);
-void play_idle(unsigned long duration_us);
+void play_idle_precise(u64 duration_ns, u64 latency_ns);
+
+static inline void play_idle(unsigned long duration_us)
+{
+ play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
+}
#ifdef CONFIG_HOTPLUG_CPU
bool cpu_wait_death(unsigned int cpu, int seconds);