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| author |   Paul E. McKenney <paulmck@kernel.org> | 2020-09-03 15:23:29 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-11-06 16:59:11 -0800 |
| commit | 3fcd6a230fa7d03bffcb831a81b40435c146c12b (patch) | |
| tree | bc576b40954c9deb95bf32151cb4535fe889297f /include/linux/rcutree.h | |
| parent | x86/cpu: Avoid cpuinfo-induced IPI pileups (diff) | |
| download | linux-dev-3fcd6a230fa7d03bffcb831a81b40435c146c12b.tar.xz linux-dev-3fcd6a230fa7d03bffcb831a81b40435c146c12b.zip | |
x86/cpu: Avoid cpuinfo-induced IPIing of idle CPUs
Currently, accessing /proc/cpuinfo sends IPIs to idle CPUs in order to
learn their clock frequency. Which is a bit strange, given that waking
them from idle likely significantly changes their clock frequency.
This commit therefore avoids sending /proc/cpuinfo-induced IPIs to
idle CPUs.
[ paulmck: Also check for idle in arch_freq_prepare_all(). ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Diffstat (limited to 'include/linux/rcutree.h')
| -rw-r--r-- | include/linux/rcutree.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 59eb5cd567d7..df578b73960f 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -50,6 +50,7 @@ void rcu_irq_exit(void); void rcu_irq_exit_preempt(void); void rcu_irq_enter_irqson(void); void rcu_irq_exit_irqson(void); +bool rcu_is_idle_cpu(int cpu); #ifdef CONFIG_PROVE_RCU void rcu_irq_exit_check_preempt(void); |