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=-7.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 C0E1AC433FE for ; Fri, 11 Dec 2020 15:44:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78C1123333 for ; Fri, 11 Dec 2020 15:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437646AbgLKPEv (ORCPT ); Fri, 11 Dec 2020 10:04:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:33306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437554AbgLKPDL (ORCPT ); Fri, 11 Dec 2020 10:03:11 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 E9569229C4; Fri, 11 Dec 2020 15:01:55 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1knjve-000TxV-6W; Fri, 11 Dec 2020 15:01:54 +0000 From: Marc Zyngier To: shawnguo@kernel.org, linux@rasmusvillemoes.dk, leoyang.li@nxp.com, mark.rutland@arm.com, zhiqiang.hou@nxp.com, Biwen Li , robh+dt@kernel.org, tglx@linutronix.de, kvmarm@lists.cs.columbia.edu, Will Deacon , kvm@vger.kernel.org, Eric Auger , Christoffer Dall , linux-arm-kernel@lists.infradead.org, Suzuki K Poulose , Shenming Lu , James Morse , Catalin Marinas , linux-kernel@vger.kernel.org, Julien Thierry Cc: xiaobo.xie@nxp.com, Hou Zhiqiang , devicetree@vger.kernel.org, Biwen Li , jiafei.pan@nxp.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com Subject: Re: [PATCH v2 0/2] KVM: arm64: Optimize the wait for the completion of the VPT analysis Date: Fri, 11 Dec 2020 15:01:39 +0000 Message-Id: <160769813659.482133.2716418035359567004.b4-ty@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201128141857.983-1-lushenming@huawei.com> References: <20201128141857.983-1-lushenming@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: shawnguo@kernel.org, linux@rasmusvillemoes.dk, leoyang.li@nxp.com, mark.rutland@arm.com, zhiqiang.hou@nxp.com, biwen.li@oss.nxp.com, robh+dt@kernel.org, tglx@linutronix.de, kvmarm@lists.cs.columbia.edu, will@kernel.org, kvm@vger.kernel.org, eric.auger@redhat.com, christoffer.dall@arm.com, linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com, lushenming@huawei.com, james.morse@arm.com, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, julien.thierry.kdev@gmail.com, xiaobo.xie@nxp.com, Zhiqiang.Hou@nxp.com, devicetree@vger.kernel.org, biwen.li@nxp.com, jiafei.pan@nxp.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 28 Nov 2020 22:18:55 +0800, Shenming Lu wrote: > Right after a vPE is made resident, the code starts polling the > GICR_VPENDBASER.Dirty bit until it becomes 0, where the delay_us > is set to 10. But in our measurement, it takes only hundreds of > nanoseconds, or 1~2 microseconds, to finish parsing the VPT in most > cases. What's more, we found that the MMIO delay on GICv4.1 system > (HiSilicon) is about 10 times higher than that on GICv4.0 system in > kvm-unit-tests (the specific data is as follows). > > [...] Applied to irq/irqchip-next, thanks! [1/2] irqchip/gic-v4.1: Reduce the delay time of the poll on the GICR_VPENDBASER.Dirty bit commit: 0b39498230ae53e6af981141be99f4c7d5144de6 Patch 2 will be routed via the KVM/arm64 tree. Cheers, M. -- Without deviation from the norm, progress is not possible.