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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 96699C433E0 for ; Sun, 17 May 2020 09:24:21 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 17B72206D5 for ; Sun, 17 May 2020 09:24:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="RAU97g05" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 17B72206D5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AB1404B0E6; Sun, 17 May 2020 05:24:20 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, body 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 MxgT3ZUxWNPD; Sun, 17 May 2020 05:24:18 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6499F4B0EA; Sun, 17 May 2020 05:24:18 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3C5584B0D3 for ; Sun, 17 May 2020 05:24:17 -0400 (EDT) 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 S7biYBSEYnq2 for ; Sun, 17 May 2020 05:24:13 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id AC6C74B0C2 for ; Sun, 17 May 2020 05:24:13 -0400 (EDT) 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 841CC206D5; Sun, 17 May 2020 09:24:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589707452; bh=HrqBD8ywpNuI1L4Z2TzDt7T36IeiriWa+zcJeJTpAjU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RAU97g052QzaYdHC61/tZZXlJL0DoRKdsSu7QxHSAOBO1GMlCm6Z/s8DNNCr9md4p Kb/922k1NCiLBHmgx5B5j0PRfStuoBnDsRHtrJqXpAPSdmCc2Kg7JfDzn4wmXTZpoe M4ToQ6SQYW8GiXyGte4yJLJXnSIN2XU55soExoho= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jaFWk-00CyXM-M0; Sun, 17 May 2020 10:24:10 +0100 MIME-Version: 1.0 Date: Sun, 17 May 2020 10:24:10 +0100 From: Marc Zyngier To: Roja Eswaran Subject: Re: Performance of VM is better than Host In-Reply-To: References: User-Agent: Roundcube Webmail/1.4.4 Message-ID: <044c89beae309b69a991ba9ea76521ea@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: reswara1@binghamton.edu, kvmarm@lists.cs.columbia.edu X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvmarm@lists.cs.columbia.edu 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu [please do not post HTML messages, and stick to plain text] On 2020-05-17 03:29, Roja Eswaran wrote: > Hello, > > I virtualized Raspi-4 and ran _sysbench - Memory_ on bare metal and > the VM. > The performance of VM is better than Host (Increase by 11%) > -> Both host and VM has the same OS > -> No Background Processes are running when sysbench is executed > -> Turned off Transparent huge pages in VM before booting > Yet getting the same performance difference. > Please let me know, What I am missing here With this level of information, I can't tell you anything. Funnily enough you're not mentioning: - what you are running (exact version and parameters of your benchmark) - what you are running it on (host configuration, parameters of the VM itself and its vmm, as "virualized Raspi-4" doesn't mean much to me) - which kernel versions - how you are measuring this discrepancy - the variability of the measurement Things you could look at: using perf capture the various counters and work out by yourself where the difference lies, look at the impact of power management on the host, the impact of other kernel threads running, the number of interrupts... HTH, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm