From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751976AbaHRPG0 (ORCPT ); Mon, 18 Aug 2014 11:06:26 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:64105 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750806AbaHRPGZ (ORCPT ); Mon, 18 Aug 2014 11:06:25 -0400 Message-ID: <53F21668.5090500@redhat.com> Date: Mon, 18 Aug 2014 17:06:16 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Andreea-Cristina Bernat , gleb@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org CC: paulmck@linux.vnet.ibm.com, monamagarwal123@gmail.com Subject: Re: [PATCH] eventfd: Replace rcu_assign_pointer() with RCU_INIT_POINTER() References: <20140818150129.GA14447@ada> In-Reply-To: <20140818150129.GA14447@ada> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 18/08/2014 17:01, Andreea-Cristina Bernat ha scritto: > 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); > } > } > Hi, this patch actually had been submitted already last March. It slipped through the cracks. I'm now applying both of Monam Agarwal's RCU_INIT_POINTER patches. Sorry. :) Thanks, Paolo