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 4E65DC433F5 for ; Wed, 12 Jan 2022 11:37:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352893AbiALLhR (ORCPT ); Wed, 12 Jan 2022 06:37:17 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:54236 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239690AbiALLhR (ORCPT ); Wed, 12 Jan 2022 06:37:17 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BDBBD61862 for ; Wed, 12 Jan 2022 11:37:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16CA5C36AE9; Wed, 12 Jan 2022 11:37:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641987436; bh=ELGmfdGB+Qa9ZMuMc84rnCgltPOBDTiQTDC3b8/gV/Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZGy6tcuT7keW17J9J4OG3QInYsviQ9vWvwEVwMJoAwrpD1ruwo9vlm1c3TcwyzqS8 vvIwPqrXl7MyjDEXqqOdYhnRx7800sGkAFKh5j4X4fKnSTBG44Jmerzh8L+I0V3YYs EqaMm6/ojOoY8JlQKSgQN4rZWVpngesHBlHVePlN+q9Z8Ggq2adpknYJI64RtN716m Q4XgvygAqpNuqlKG7XfEq+jdO36wf1XIH0F747LFAcx+TAwBFb7YW9v4whC6lcqy+T HtvIhXwo1ohSidfzouYZnmmU/GX27/sJhFroOfHkgVNoNOcn97SyI5ef2BT4+MRzUR KeWhLw48RMBQA== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1n7bwH-00021I-Dp; Wed, 12 Jan 2022 11:37:13 +0000 Date: Wed, 12 Jan 2022 11:37:12 +0000 Message-ID: <87sfttrxqv.wl-maz@kernel.org> From: Marc Zyngier To: Jing Zhang Cc: KVM , KVMARM , Will Deacon , Paolo Bonzini , David Matlack , Oliver Upton , Reiji Watanabe , Raghavendra Rao Ananta Subject: Re: [RFC PATCH 3/3] KVM: selftests: Add vgic initialization for dirty log perf test for ARM In-Reply-To: References: <20220110210441.2074798-1-jingzhangos@google.com> <20220110210441.2074798-4-jingzhangos@google.com> <87a6g2tvia.wl-maz@kernel.org> 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/27.1 (x86_64-pc-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: jingzhangos@google.com, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, pbonzini@redhat.com, dmatlack@google.com, oupton@google.com, reijiw@google.com, rananta@google.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 Tue, 11 Jan 2022 22:16:01 +0000, Jing Zhang wrote: > > On Tue, Jan 11, 2022 at 2:30 AM Marc Zyngier wrote: > > > > On Mon, 10 Jan 2022 21:04:41 +0000, > > Jing Zhang wrote: > > > > > > For ARM64, if no vgic is setup before the dirty log perf test, the > > > userspace irqchip would be used, which would affect the dirty log perf > > > test result. > > > > Doesn't it affect *all* performance tests? How much does this change > > contributes to the performance numbers you give in the cover letter? > > > This bottleneck showed up after adding the fast path patch. I didn't > try other performance tests with this, but I think it is a good idea > to add a vgic setup for all performance tests. I can post another > patch later to make it available for all performance tests after > finishing this one and verifying all other performance tests. > Below is the test result without adding the vgic setup. It shows > 20~30% improvement for the different number of vCPUs. > +-------+------------------------+ > | #vCPU | dirty memory time (ms) | > +-------+------------------------+ > | 1 | 965 | > +-------+------------------------+ > | 2 | 1006 | > +-------+------------------------+ > | 4 | 1128 | > +-------+------------------------+ > | 8 | 2005 | > +-------+------------------------+ > | 16 | 3903 | > +-------+------------------------+ > | 32 | 7595 | > +-------+------------------------+ > | 64 | 15783 | > +-------+------------------------+ So please use these numbers in your cover letter when you repost your series, as the improvement you'd observe on actual workloads is likely to be less than what you claim due to this change in the test itself (in other words, if you are going to benchamark something, don't change the benchmark halfway). M. -- Without deviation from the norm, progress is not possible. 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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00E8CC433EF for ; Wed, 12 Jan 2022 11:37:23 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 701674B1C9; Wed, 12 Jan 2022 06:37:23 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4HuNvRZpo1Xm; Wed, 12 Jan 2022 06:37:21 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2E5A44B172; Wed, 12 Jan 2022 06:37:21 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2A6FD49E22 for ; Wed, 12 Jan 2022 06:37:20 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XNZP3F7iP2cr for ; Wed, 12 Jan 2022 06:37:17 -0500 (EST) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id D8F3549E21 for ; Wed, 12 Jan 2022 06:37:17 -0500 (EST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BEEF561870; Wed, 12 Jan 2022 11:37:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16CA5C36AE9; Wed, 12 Jan 2022 11:37:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641987436; bh=ELGmfdGB+Qa9ZMuMc84rnCgltPOBDTiQTDC3b8/gV/Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZGy6tcuT7keW17J9J4OG3QInYsviQ9vWvwEVwMJoAwrpD1ruwo9vlm1c3TcwyzqS8 vvIwPqrXl7MyjDEXqqOdYhnRx7800sGkAFKh5j4X4fKnSTBG44Jmerzh8L+I0V3YYs EqaMm6/ojOoY8JlQKSgQN4rZWVpngesHBlHVePlN+q9Z8Ggq2adpknYJI64RtN716m Q4XgvygAqpNuqlKG7XfEq+jdO36wf1XIH0F747LFAcx+TAwBFb7YW9v4whC6lcqy+T HtvIhXwo1ohSidfzouYZnmmU/GX27/sJhFroOfHkgVNoNOcn97SyI5ef2BT4+MRzUR KeWhLw48RMBQA== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1n7bwH-00021I-Dp; Wed, 12 Jan 2022 11:37:13 +0000 Date: Wed, 12 Jan 2022 11:37:12 +0000 Message-ID: <87sfttrxqv.wl-maz@kernel.org> From: Marc Zyngier To: Jing Zhang Subject: Re: [RFC PATCH 3/3] KVM: selftests: Add vgic initialization for dirty log perf test for ARM In-Reply-To: References: <20220110210441.2074798-1-jingzhangos@google.com> <20220110210441.2074798-4-jingzhangos@google.com> <87a6g2tvia.wl-maz@kernel.org> 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/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: jingzhangos@google.com, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, pbonzini@redhat.com, dmatlack@google.com, oupton@google.com, reijiw@google.com, rananta@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: KVM , David Matlack , Paolo Bonzini , Will Deacon , KVMARM X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Tue, 11 Jan 2022 22:16:01 +0000, Jing Zhang wrote: > > On Tue, Jan 11, 2022 at 2:30 AM Marc Zyngier wrote: > > > > On Mon, 10 Jan 2022 21:04:41 +0000, > > Jing Zhang wrote: > > > > > > For ARM64, if no vgic is setup before the dirty log perf test, the > > > userspace irqchip would be used, which would affect the dirty log perf > > > test result. > > > > Doesn't it affect *all* performance tests? How much does this change > > contributes to the performance numbers you give in the cover letter? > > > This bottleneck showed up after adding the fast path patch. I didn't > try other performance tests with this, but I think it is a good idea > to add a vgic setup for all performance tests. I can post another > patch later to make it available for all performance tests after > finishing this one and verifying all other performance tests. > Below is the test result without adding the vgic setup. It shows > 20~30% improvement for the different number of vCPUs. > +-------+------------------------+ > | #vCPU | dirty memory time (ms) | > +-------+------------------------+ > | 1 | 965 | > +-------+------------------------+ > | 2 | 1006 | > +-------+------------------------+ > | 4 | 1128 | > +-------+------------------------+ > | 8 | 2005 | > +-------+------------------------+ > | 16 | 3903 | > +-------+------------------------+ > | 32 | 7595 | > +-------+------------------------+ > | 64 | 15783 | > +-------+------------------------+ So please use these numbers in your cover letter when you repost your series, as the improvement you'd observe on actual workloads is likely to be less than what you claim due to this change in the test itself (in other words, if you are going to benchamark something, don't change the benchmark halfway). M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm