On Mon, Sep 26, 2022 at 10:36:29PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 26, 2022 at 09:58:27AM +0800, Yipeng Zou wrote:
> > The commit "x86/cpu: Avoid cpuinfo-induced IPIing of idle CPUs" introduce
> > this function to identify the current CPU idle state.
> > But after commit "x86/aperfmperf: Replace arch_freq_get_on_cpu()" we
> > just use MAX_SAMPLE_AGE to do that, So there is no use of this function.
> >
> > Fixes: f3eca381bd49 ("x86/aperfmperf: Replace arch_freq_get_on_cpu()")
> > Signed-off-by: Yipeng Zou <zouyipeng@xxxxxxxxxx>
>
> Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Good eyes, Yipeng! Queued and pushed, thank you both!
As usual, I could not resist the urge to wordsmith, so please check the
patch below and let me know if I messed something up.
And please include both commit IDs in future patches with the
formatting shows below. Makes it easier for me to accept your
patches, after all. ;-)
Thanx, Paul
------------------------------------------------------------------------
commit f8b389c24cf9a523472e3e505815b26f0174856c
Author: Yipeng Zou <zouyipeng@xxxxxxxxxx>
Date: Mon Sep 26 09:58:27 2022 +0800
rcu: Remove rcu_is_idle_cpu()
The commit 3fcd6a230fa7 ("x86/cpu: Avoid cpuinfo-induced IPIing of
idle CPUs") introduced rcu_is_idle_cpu() in order to identify the
current CPU idle state. But commit f3eca381bd49 ("x86/aperfmperf:
Replace arch_freq_get_on_cpu()") switched to using MAX_SAMPLE_AGE,
so rcu_is_idle_cpu() is no longer used. This commit therefore removes it.
Fixes: f3eca381bd49 ("x86/aperfmperf: Replace arch_freq_get_on_cpu()")
Signed-off-by: Yipeng Zou <zouyipeng@xxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 84e930c11065..93485b812712 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -146,8 +146,6 @@ static inline void rcu_virt_note_context_switch(void) { }
static inline void rcu_cpu_stall_reset(void) { }
static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ; }
static inline void rcu_irq_exit_check_preempt(void) { }
-#define rcu_is_idle_cpu(cpu) \
- (is_idle_task(current) && !in_nmi() && !in_hardirq() && !in_serving_softirq())
static inline void exit_rcu(void) { }
static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
{
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 3066e0975022..f41c4ab2a884 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -87,8 +87,6 @@ bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
void cond_synchronize_rcu(unsigned long oldstate);
void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
-bool rcu_is_idle_cpu(int cpu);
-
#ifdef CONFIG_PROVE_RCU
void rcu_irq_exit_check_preempt(void);
#else
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1930cee1ccdb..96d678c9cfb6 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -301,12 +301,6 @@ static bool rcu_dynticks_in_eqs(int snap)
return !(snap & RCU_DYNTICKS_IDX);
}
-/* Return true if the specified CPU is currently idle from an RCU viewpoint. */
-bool rcu_is_idle_cpu(int cpu)
-{
- return rcu_dynticks_in_eqs(rcu_dynticks_snap(cpu));
-}
-
/*
* Return true if the CPU corresponding to the specified rcu_data
* structure has spent some time in an extended quiescent state since
