path: root/include
diff options
authorThomas Gleixner <tglx@linutronix.de>2015-07-07 14:29:38 (GMT)
committerThomas Gleixner <tglx@linutronix.de>2015-07-07 16:46:47 (GMT)
commitf32dd117051185da6e923b35491a44d7debeeea5 (patch)
treeb714e69a520539388c31ee0fd2af28211a83aa82 /include
parente0454311903d3fd0f12a86c9e65d7b271c2bb05d (diff)
tick/broadcast: Make idle check independent from mode and config
Currently the broadcast busy check, which prevents the idle code from going into deep idle, works only in one shot mode. If NOHZ and HIGHRES are off (config or command line) there is no sanity check at all, so under certain conditions cpus are allowed to go into deep idle, where the local timer stops, and are not woken up again because there is no broadcast timer installed or a hrtimer based broadcast device is not evaluated. Move tick_broadcast_oneshot_control() into the common code and provide proper subfunctions for the various config combinations. The common check in tick_broadcast_oneshot_control() is for the C3STOP misfeature flag of the local clock event device. If its not set, idle can proceed. If set, further checks are necessary. Provide checks for the trivial cases: - If broadcast is disabled in the config, then return busy - If oneshot mode (NOHZ/HIGHES) is disabled in the config, return busy if the broadcast device is hrtimer based. - If oneshot mode is enabled in the config call the original tick_broadcast_oneshot_control() function. That function needs extra checks which will be implemented in seperate patches. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
Diffstat (limited to 'include')
1 files changed, 0 insertions, 4 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 3741ba1..6916dcb 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -67,11 +67,7 @@ extern void tick_broadcast_control(enum tick_broadcast_mode mode);
static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
#endif /* BROADCAST */
extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
-static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state) { return 0; }
static inline void tick_broadcast_enable(void)

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