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| author | Will Deacon <will@kernel.org> | 2021-05-24 23:18:16 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-05-31 17:04:45 +0200 |
| commit | c94a8537df12708cc03da9120c3c3561ae744ce1 (patch) | |
| tree | a3d59a3f9da19632708e5bdf3a29d2e0729ab4be /kernel/time/tick-internal.h | |
| parent | e5007c288e7981e0b0cf8ea3dea443f0b8c34345 (diff) | |
| download | linux-stable-c94a8537df12708cc03da9120c3c3561ae744ce1.tar.gz linux-stable-c94a8537df12708cc03da9120c3c3561ae744ce1.tar.bz2 linux-stable-c94a8537df12708cc03da9120c3c3561ae744ce1.zip | |
tick/broadcast: Prefer per-cpu oneshot wakeup timers to broadcast
Some SoCs have two per-cpu timer implementations where the timer with the
higher rating stops in deep idle (i.e. suffers from CLOCK_EVT_FEAT_C3STOP)
but is otherwise preferable to the timer with the lower rating. In such a
design, selecting the higher rated devices relies on a global broadcast
timer and IPIs to wake up from deep idle states.
To avoid the reliance on a global broadcast timer and also to reduce the
overhead associated with the IPI wakeups, extend
tick_install_broadcast_device() to manage per-cpu wakeup timers separately
from the broadcast device.
For now, these timers remain unused.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210524221818.15850-4-will@kernel.org
Diffstat (limited to 'kernel/time/tick-internal.h')
| -rw-r--r-- | kernel/time/tick-internal.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 7a981c9e87a4..30c89639e305 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -61,7 +61,7 @@ extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); /* Broadcasting support */ # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu); -extern void tick_install_broadcast_device(struct clock_event_device *dev); +extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu); extern int tick_is_broadcast_device(struct clock_event_device *dev); extern void tick_suspend_broadcast(void); extern void tick_resume_broadcast(void); @@ -72,7 +72,7 @@ extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq); extern struct tick_device *tick_get_broadcast_device(void); extern struct cpumask *tick_get_broadcast_mask(void); # else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */ -static inline void tick_install_broadcast_device(struct clock_event_device *dev) { } +static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { } static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; } static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; } static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { } |