From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Date: Fri, 22 Jul 2016 14:44:02 +0200 (CEST) Message-ID: References: <1468933367-23159-1-git-send-email-eric.auger@redhat.com> <1468933367-23159-7-git-send-email-eric.auger@redhat.com> <3f188661-1d68-199b-3fcc-4da432bae633@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <3f188661-1d68-199b-3fcc-4da432bae633@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Auger Eric Cc: kvm@vger.kernel.org, will.deacon@arm.com, kvmarm@lists.cs.columbia.edu, eric.auger.pro@gmail.com, joro@8bytes.org, robert.richter@caviumnetworks.com, jason@lakedaemon.net, marc.zyngier@arm.com, andre.przywara@arm.com, Manish.Jaggi@caviumnetworks.com, alex.williamson@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, pbonzini@redhat.com, robin.murphy@arm.com List-Id: iommu@lists.linux-foundation.org On Thu, 21 Jul 2016, Auger Eric wrote: > On 20/07/2016 10:12, Thomas Gleixner wrote: > > On Tue, 19 Jul 2016, Eric Auger wrote: > >> +bool msi_doorbell_safe(void) > >> +{ > >> + struct irqchip_doorbell *db; > >> + bool irq_remapping = true; > >> + > >> + mutex_lock(&irqchip_doorbell_mutex); > >> + list_for_each_entry(db, &irqchip_doorbell_list, next) { > >> + irq_remapping &= db->info.irq_remapping; > > > > db->info.irq_remapping is set in msi_doorbell_register(). So you can keep book > > about that there. No need to iterate here. > Yes makes sense to store the info at registration time. Currently this > function is not in any fast path but that's cleaner from a general > perspective. I will need to do such iteration at un-registration though. Two simple counter should be sufficient. nr_registered_bells; nr_remapped_bells; .... Thanks, tglx