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authorJoel Fernandes (Google) <joel@joelfernandes.org>2023-01-24 17:31:26 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-05-17 11:13:22 +0200
commitea134c3e80599a40b9efd7ab14898fef0737d4d3 (patch)
tree0488ab53fe120bc8f350380dfb7fc97a097706cc /include/linux
parentfe2ae32a7ec9fa64f61993b808f25315b9996b03 (diff)
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
[ Upstream commit 58d7668242647e661a20efe065519abd6454287e ] For CONFIG_NO_HZ_FULL systems, the tick_do_timer_cpu cannot be offlined. However, cpu_is_hotpluggable() still returns true for those CPUs. This causes torture tests that do offlining to end up trying to offline this CPU causing test failures. Such failure happens on all architectures. Fix the repeated error messages thrown by this (even if the hotplug errors are harmless) by asking the opinion of the nohz subsystem on whether the CPU can be hotplugged. [ Apply Frederic Weisbecker feedback on refactoring tick_nohz_cpu_down(). ] For drivers/base/ portion: Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Zhouyi Zhou <zhouzhouyi@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: rcu <rcu@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: 2987557f52b9 ("driver-core/cpu: Expose hotpluggability to the rest of the kernel") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/tick.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 965163bdfe41..443726085f6c 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -197,6 +197,7 @@ extern void tick_nohz_dep_set_signal(struct signal_struct *signal,
enum tick_dep_bits bit);
extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
enum tick_dep_bits bit);
+extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu);
/*
* The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
@@ -261,6 +262,7 @@ static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
+static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; }
static inline void tick_dep_set(enum tick_dep_bits bit) { }
static inline void tick_dep_clear(enum tick_dep_bits bit) { }