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| author | Thomas Gleixner <tglx@linutronix.de> | 2024-02-29 15:23:36 +0100 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-03-01 21:04:27 +0100 |
| commit | 2be2a197ff6c3a659ab9285e1d88cbdc609ac6de (patch) | |
| tree | e742ba7b20801029543c26db8d259147194b0c9a /kernel/time | |
| parent | x86: Increase brk randomness entropy for 64-bit systems (diff) | |
| download | linux-2be2a197ff6c3a659ab9285e1d88cbdc609ac6de.tar.xz linux-2be2a197ff6c3a659ab9285e1d88cbdc609ac6de.zip | |
sched/idle: Conditionally handle tick broadcast in default_idle_call()
The x86 architecture has an idle routine for AMD CPUs which are affected
by erratum 400. On the affected CPUs the local APIC timer stops in the
C1E halt state.
It therefore requires tick broadcasting. The invocation of
tick_broadcast_enter()/exit() from this function violates the RCU
constraints because it can end up in lockdep or tracing, which
rightfully triggers a warning.
tick_broadcast_enter()/exit() must be invoked before ct_cpuidle_enter()
and after ct_cpuidle_exit() in default_idle_call().
Add a static branch conditional invocation of tick_broadcast_enter()/exit()
into this function to allow X86 to replace the AMD specific idle code. It's
guarded by a config switch which will be selected by x86. Otherwise it's
a NOOP.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240229142248.266708822@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/Kconfig | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index bae8f11070be..fc3b1a06c981 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -39,6 +39,11 @@ config GENERIC_CLOCKEVENTS_BROADCAST bool depends on GENERIC_CLOCKEVENTS +# Handle broadcast in default_idle_call() +config GENERIC_CLOCKEVENTS_BROADCAST_IDLE + bool + depends on GENERIC_CLOCKEVENTS_BROADCAST + # Automatically adjust the min. reprogramming time for # clock event device config GENERIC_CLOCKEVENTS_MIN_ADJUST |