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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 30C61C43441 for ; Sun, 11 Nov 2018 22:32:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E266D223DD for ; Sun, 11 Nov 2018 22:32:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XFV/4jKw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E266D223DD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403865AbeKLIWu (ORCPT ); Mon, 12 Nov 2018 03:22:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:54556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390859AbeKLIWu (ORCPT ); Mon, 12 Nov 2018 03:22:50 -0500 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 07B3D21582; Sun, 11 Nov 2018 22:32:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975573; bh=F0JZicURmuAXopggUdOW2X23I5Ov6rVNLoidYsapcP8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XFV/4jKwyzgCIl7ODQyw0c8q3DcaVeiN0esM7nRCeZvnRhetv0rOtEhy7AlsS8Cus l8G9alA8z5BQgRT7/25SxO6HyIZkfF/z0ROy35509kd+k11vZAUiSLJ/uVyVSEsA28 /aV58zCmW5j4cgYYmsxXgDbNx625RtqLe8hbGszo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Keith Busch , Lorenzo Pieralisi , "Jon Derrick:" , "Heitke, Kenneth" Subject: [PATCH 4.14 148/222] PCI: vmd: White list for fast interrupt handlers Date: Sun, 11 Nov 2018 14:24:05 -0800 Message-Id: <20181111221700.645578642@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221647.665769131@linuxfoundation.org> References: <20181111221647.665769131@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Keith Busch commit a7f58b9ecfd3c0f63703ec10f4a592cc38dbd1b8 upstream. Devices with slow interrupt handlers are significantly harming performance when their interrupt vector is shared with a fast device. Create a class code white list for devices with known fast interrupt handlers and let all other devices share a single vector so that they don't interfere with performance. At the moment, only the NVM Express class code is on the list, but more may be added if VMD users desire to use other low-latency devices in these domains. Signed-off-by: Keith Busch [lorenzo.pieralisi@arm.com: changelog] Signed-off-by: Lorenzo Pieralisi Acked-by: Jon Derrick: Cc: "Heitke, Kenneth" Signed-off-by: Greg Kroah-Hartman --- drivers/pci/host/vmd.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/drivers/pci/host/vmd.c +++ b/drivers/pci/host/vmd.c @@ -183,9 +183,20 @@ static struct vmd_irq_list *vmd_next_irq int i, best = 1; unsigned long flags; - if (pci_is_bridge(msi_desc_to_pci_dev(desc)) || vmd->msix_count == 1) + if (vmd->msix_count == 1) return &vmd->irqs[0]; + /* + * White list for fast-interrupt handlers. All others will share the + * "slow" interrupt vector. + */ + switch (msi_desc_to_pci_dev(desc)->class) { + case PCI_CLASS_STORAGE_EXPRESS: + break; + default: + 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)