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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23853EE57DA for ; Fri, 8 Sep 2023 07:21:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238198AbjIHHVz (ORCPT ); Fri, 8 Sep 2023 03:21:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230143AbjIHHVy (ORCPT ); Fri, 8 Sep 2023 03:21:54 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E75111BC8 for ; Fri, 8 Sep 2023 00:21:50 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 740C6C433C7; Fri, 8 Sep 2023 07:21:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694157710; bh=hlIhJE37roD5m52PpdY5rfE7FOoKJCNEwPzflmRv0T0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=D/ynPj79vSCSk4N2ObB33HQKPgPKX3Sduc54P1euof5oDbPRKk8WHhYj1fDK2IjMQ ri8scMbD7KqSxkRHIZQQuwTPWsbm0o20tXVXJCR8o919WQBbNQ/byrKF/69b9CjVXf cXLmDElj5YYYO0rl2GifqRc4QhfBSFb3+xgqAeqEC1Z+G7hrk9SPWJl7LOoxxXTKCp CzfhJKDzQeWmgi3yRTLOqR7BzhtebyAIeODyolt1U/4G6JVentY3QCz0GEMk4WBWuy yvsYEMGgjIVHY1C8YXSjMFsS24RlIllUMyUBFauCg6c0tAv6q9F/lZjPOdi3MYtOzl b0VlyIZIqEqGw== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qeVoJ-00BILK-RH; Fri, 08 Sep 2023 08:21:47 +0100 Date: Fri, 08 Sep 2023 08:21:47 +0100 Message-ID: <86cyytdt9w.wl-maz@kernel.org> From: Marc Zyngier To: Joey Gouly Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Xu Zhao Subject: Re: [PATCH 0/5] KVM: arm64: Accelerate lookup of vcpus by MPIDR values In-Reply-To: <20230907202712.GA171716@e124191.cambridge.arm.com> References: <20230907100931.1186690-1-maz@kernel.org> <20230907153052.GD69899@e124191.cambridge.arm.com> <871qf9q25c.wl-maz@kernel.org> <20230907202712.GA171716@e124191.cambridge.arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: joey.gouly@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, zhaoxu.35@bytedance.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: kvm@vger.kernel.org On Thu, 07 Sep 2023 21:27:12 +0100, Joey Gouly wrote: > > On Thu, Sep 07, 2023 at 07:17:03PM +0100, Marc Zyngier wrote: > > On Thu, 07 Sep 2023 16:30:52 +0100, > > Joey Gouly wrote: > > > > [...] > > > > > Got a roughly similar perf improvement (about 28%). > > > > Out of curiosity, on which HW? > > I used QEMU emulation, but was told after posting this that QEMU is probably > not good to be used for perf measurments? Sorry about that. I can retry on Juno > tomorrow if that's of any use. Indeed, using models for performance measurement is pretty unreliable, and will give you a rather different profile from the HW. Unfortunately, Juno has only a GICv2, which won't see any significant gain. You'll need something with a GICv3, as the whole interrupt routing (SGI and SPI) is MPIDR based. Thanks, M. -- Without deviation from the norm, progress is not possible.