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Subject: Re: [PATCH] kvm/eventfd:do wildcard calculation before
 list_for_each_entry_safe
To:     Yi Li <yili@winhong.com>
Cc:     yilikernel@gmail.com, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
References: <20200911055652.3041762-1-yili@winhong.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20efe3ed-8efa-ed50-bd01-329db676ee86@redhat.com>
Date:   Fri, 11 Sep 2020 19:23:40 +0200
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On 11/09/20 07:56, Yi Li wrote:
> There is no need to calculate wildcard in each loop
> since wildcard is not changed.
> 
> Signed-off-by: Yi Li <yili@winhong.com>
> ---
>  virt/kvm/eventfd.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index d6408bb497dc..c2323c27a28b 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -853,15 +853,17 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
>  	struct eventfd_ctx       *eventfd;
>  	struct kvm_io_bus	 *bus;
>  	int                       ret = -ENOENT;
> +	bool                      wildcard;
>  
>  	eventfd = eventfd_ctx_fdget(args->fd);
>  	if (IS_ERR(eventfd))
>  		return PTR_ERR(eventfd);
>  
> +	wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
> +
>  	mutex_lock(&kvm->slots_lock);
>  
>  	list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
> -		bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
>  
>  		if (p->bus_idx != bus_idx ||
>  		    p->eventfd != eventfd  ||
> 

Queued, thanks.

Paolo