From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3D9DCA9EC3 for ; Thu, 31 Oct 2019 11:24:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0E8C20650 for ; Thu, 31 Oct 2019 11:24:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbfJaLY2 (ORCPT ); Thu, 31 Oct 2019 07:24:28 -0400 Received: from foss.arm.com ([217.140.110.172]:47446 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726455AbfJaLY2 (ORCPT ); Thu, 31 Oct 2019 07:24:28 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4AB641F1; Thu, 31 Oct 2019 04:24:27 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (unknown [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 986513F719; Thu, 31 Oct 2019 04:24:26 -0700 (PDT) Date: Thu, 31 Oct 2019 11:24:24 +0000 From: Lorenzo Pieralisi To: Jon Derrick Cc: Bjorn Helgaas , Keith Busch , linux-pci@vger.kernel.org Subject: Re: [PATCH 2/2] PCI: vmd: Add indirection layer to vmd irq lists Message-ID: <20191031112424.GB26080@e121166-lin.cambridge.arm.com> References: <1571658459-5668-1-git-send-email-jonathan.derrick@intel.com> <1571658459-5668-3-git-send-email-jonathan.derrick@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1571658459-5668-3-git-send-email-jonathan.derrick@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Oct 21, 2019 at 05:47:39AM -0600, Jon Derrick wrote: > With CONFIG_MAXSMP and other debugging options enabled, the size of an > srcu_struct can grow quite large. These are embedded in the vmd_irq_list > struct, and a N=64 allocation can exceed MAX_ORDER, violating reclaim > rules. > > This patch changes the irq list array into an array of pointers to irq > lists to avoid allocation failures with greater msix counts. > > Signed-off-by: Jon Derrick > --- > drivers/pci/controller/vmd.c | 33 ++++++++++++++++++++------------- > 1 file changed, 20 insertions(+), 13 deletions(-) Hi Jon, I think that for bisectability reasons these two patches should be squashed together. Also if you can provide more fine grain details of what we are fixing in the commit log I think that would be beneficial. Thanks, Lorenzo > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index c4de95a..096006e 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -92,7 +92,7 @@ struct vmd_dev { > char __iomem *cfgbar; > > int msix_count; > - struct vmd_irq_list *irqs; > + struct vmd_irq_list **irqs; > > struct pci_sysdata sysdata; > struct resource resources[3]; > @@ -194,7 +194,7 @@ static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *d > unsigned long flags; > > if (vmd->msix_count == 1) > - return &vmd->irqs[0]; > + return vmd->irqs[0]; > > /* > * White list for fast-interrupt handlers. All others will share the > @@ -204,17 +204,17 @@ static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *d > case PCI_CLASS_STORAGE_EXPRESS: > break; > default: > - return &vmd->irqs[0]; > + return vmd->irqs[0]; > } > > raw_spin_lock_irqsave(&list_lock, flags); > for (i = 1; i < vmd->msix_count; i++) > - if (vmd->irqs[i].count < vmd->irqs[best].count) > + if (vmd->irqs[i]->count < vmd->irqs[best]->count) > best = i; > - vmd->irqs[best].count++; > + vmd->irqs[best]->count++; > raw_spin_unlock_irqrestore(&list_lock, flags); > > - return &vmd->irqs[best]; > + return vmd->irqs[best]; > } > > static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, > @@ -764,15 +764,22 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id) > return -ENOMEM; > > for (i = 0; i < vmd->msix_count; i++) { > - err = init_srcu_struct(&vmd->irqs[i].srcu); > + vmd->irqs[i] = devm_kcalloc(&dev->dev, 1, sizeof(**vmd->irqs), > + GFP_KERNEL); > + if (!vmd->irqs[i]) > + return -ENOMEM; > + } > + > + for (i = 0; i < vmd->msix_count; i++) { > + err = init_srcu_struct(&vmd->irqs[i]->srcu); > if (err) > return err; > > - INIT_LIST_HEAD(&vmd->irqs[i].irq_list); > - vmd->irqs[i].index = i; > + INIT_LIST_HEAD(&vmd->irqs[i]->irq_list); > + vmd->irqs[i]->index = i; > err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i), > vmd_irq, IRQF_NO_THREAD, > - "vmd", &vmd->irqs[i]); > + "vmd", vmd->irqs[i]); > if (err) > return err; > } > @@ -793,7 +800,7 @@ static void vmd_cleanup_srcu(struct vmd_dev *vmd) > int i; > > for (i = 0; i < vmd->msix_count; i++) > - cleanup_srcu_struct(&vmd->irqs[i].srcu); > + cleanup_srcu_struct(&vmd->irqs[i]->srcu); > } > > static void vmd_remove(struct pci_dev *dev) > @@ -817,7 +824,7 @@ static int vmd_suspend(struct device *dev) > int i; > > for (i = 0; i < vmd->msix_count; i++) > - devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]); > + devm_free_irq(dev, pci_irq_vector(pdev, i), vmd->irqs[i]); > > pci_save_state(pdev); > return 0; > @@ -832,7 +839,7 @@ static int vmd_resume(struct device *dev) > for (i = 0; i < vmd->msix_count; i++) { > err = devm_request_irq(dev, pci_irq_vector(pdev, i), > vmd_irq, IRQF_NO_THREAD, > - "vmd", &vmd->irqs[i]); > + "vmd", vmd->irqs[i]); > if (err) > return err; > } > -- > 1.8.3.1 >