On 1/22/2025 1:04 PM, lirongqing wrote:
> From: Li RongQing <lirongqing@xxxxxxxxx>
>
> The callback function of call_rcu() just calls kvfree(), so we can
> use kvfree_rcu() instead of call_rcu() + callback function.
>
Reword to imperative style?
The callback function of call_rcu() just calls kvfree(). So, use
kvfree_rcu() instead of call_rcu() + callback function.
> Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> ---
> arch/x86/kvm/lapic.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 3c83951..d6e62a2 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -221,13 +221,6 @@ static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map,
> }
> }
>
> -static void kvm_apic_map_free(struct rcu_head *rcu)
> -{
> - struct kvm_apic_map *map = container_of(rcu, struct kvm_apic_map, rcu);
> -
> - kvfree(map);
> -}
> -
> static int kvm_recalculate_phys_map(struct kvm_apic_map *new,
> struct kvm_vcpu *vcpu,
> bool *xapic_id_mismatch)
> @@ -489,7 +482,7 @@ static void kvm_recalculate_apic_map(struct kvm *kvm)
> mutex_unlock(&kvm->arch.apic_map_lock);
>
> if (old)
> - call_rcu(&old->rcu, kvm_apic_map_free);
> + kvfree_rcu(old, rcu);
>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx>
Just a note: rcu_barrier() does not wait for kvfree_rcu() callbacks to complete. It only
waits for call_rcu() callbacks. For kvfree_rcu() callbacks, kvfree_rcu_barrier()
is required to wait for previously enqueued kvfree_rcu() callbacks to complete. As
rcu_barrier() is not used for apic_map free callbacks, this looks fine.
- Neeraj
> kvm_make_scan_ioapic_request(kvm);
> }
