From: Waiman Long Date: Tue, 29 Jul 2025 19:12:32 +0000 (-0400) Subject: cpu: Remove obsolete comment from takedown_cpu() X-Git-Tag: v6.17-rc1~2^2 X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=da274853fe7dbc7124e2dd84dad802be52a09321;p=thirdparty%2Fkernel%2Flinux.git cpu: Remove obsolete comment from takedown_cpu() takedown_cpu() has a comment about "all preempt/rcu users must observe !cpu_active()" which is kind of meaningless in this function. This comment was originally introduced by commit 6acce3ef8452 ("sched: Remove get_online_cpus() usage") when _cpu_down() was setting cpu_active_mask and synchronize_rcu()/synchronize_sched() were added after that. Later commit 40190a78f85f ("sched/hotplug: Convert cpu_[in]active notifiers to state machine") added a new CPUHP_AP_ACTIVE hotplug state to set/clear cpu_active_mask. The following commit b2454caa8977 ("sched/hotplug: Move sync_rcu to be with set_cpu_active(false)") move the synchronize_*() calls to sched_cpu_deactivate() associated with the new hotplug state, but left the comment behind. Remove this comment as it is no longer relevant in takedown_cpu(). Signed-off-by: Waiman Long Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250729191232.664931-1-longman@redhat.com --- diff --git a/kernel/cpu.c b/kernel/cpu.c index faf0f23fc5d8..db9f6c539b28 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1309,9 +1309,6 @@ static int takedown_cpu(unsigned int cpu) */ irq_lock_sparse(); - /* - * So now all preempt/rcu users must observe !cpu_active(). - */ err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); if (err) { /* CPU refused to die */