From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreea-Cristina Bernat Subject: [PATCH] eventfd: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Date: Mon, 18 Aug 2014 18:01:29 +0300 Message-ID: <20140818150129.GA14447@ada> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: paulmck@linux.vnet.ibm.com To: gleb@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from mail-lb0-f173.google.com ([209.85.217.173]:51590 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751669AbaHRPBj (ORCPT ); Mon, 18 Aug 2014 11:01:39 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: The uses of "rcu_assign_pointer()" are NULLing out the pointers. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat --- virt/kvm/eventfd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 20c3af7..a49130f 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -278,7 +278,7 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd, struct kvm_kernel_irq_routing_entry *e; if (irqfd->gsi >= irq_rt->nr_rt_entries) { - rcu_assign_pointer(irqfd->irq_entry, NULL); + RCU_INIT_POINTER(irqfd->irq_entry, NULL); return; } @@ -287,7 +287,7 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd, if (e->type == KVM_IRQ_ROUTING_MSI) rcu_assign_pointer(irqfd->irq_entry, e); else - rcu_assign_pointer(irqfd->irq_entry, NULL); + RCU_INIT_POINTER(irqfd->irq_entry, NULL); } } @@ -473,7 +473,7 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args) * It is paired with synchronize_srcu done by caller * of that function. */ - rcu_assign_pointer(irqfd->irq_entry, NULL); + RCU_INIT_POINTER(irqfd->irq_entry, NULL); irqfd_deactivate(irqfd); } } -- 1.9.1