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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 77DBBC433DF for ; Tue, 26 May 2020 11:38:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 560592084C for ; Tue, 26 May 2020 11:38:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590493137; bh=Wajw1ceENB9jmRhxQhR29w1N42Not5ApNmO0wbs23pY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=dvAgHkwZGfb0E4v2xhE268U3fxiIoHPyk49N+mWG9pBN0T+pYuA9YWiiCqp6Pb4tH upebE5glklu3Cy+5DzuH2eKg+iBWx+r/Mr/dF5RwGVcBar+qMf8fVnE3rR7XMJ9d28 IK1+NoH37zFnFOGwl62OWwGv98GKsRwd4IJfM8sk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731922AbgEZLi4 (ORCPT ); Tue, 26 May 2020 07:38:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:43714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731446AbgEZLix (ORCPT ); Tue, 26 May 2020 07:38:53 -0400 Received: from kernel.org (unknown [87.70.212.59]) (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 C32A1207CB; Tue, 26 May 2020 11:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590493133; bh=Wajw1ceENB9jmRhxQhR29w1N42Not5ApNmO0wbs23pY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1N6YuY0hI/08pJzS1NvVuzOOBihDQpySVba0Krk295SyXzDWHiffI26uav4ppjIbs wQGF3JptzzAzWlYbkIxctDjMjC9vTc8hSrONfenzVWnDWmDunT42Q++sXWRJSEm7wM Dj6Y3E0YTUqm2BpIau0CmHykWgCcHsYOQy/5HTz4= Date: Tue, 26 May 2020 14:38:44 +0300 From: Mike Rapoport To: Liran Alon Cc: "Kirill A. Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [RFC 00/16] KVM protected memory extension Message-ID: <20200526113844.GC48741@kernel.org> References: <20200522125214.31348-1-kirill.shutemov@linux.intel.com> <42685c32-a7a9-b971-0cf4-e8af8d9a40c6@oracle.com> <20200526061721.GB48741@kernel.org> <8866ff79-e8fd-685d-9a1d-72acff5bf6bb@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8866ff79-e8fd-685d-9a1d-72acff5bf6bb@oracle.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 26, 2020 at 01:16:14PM +0300, Liran Alon wrote: > > On 26/05/2020 9:17, Mike Rapoport wrote: > > On Mon, May 25, 2020 at 04:47:18PM +0300, Liran Alon wrote: > > > On 22/05/2020 15:51, Kirill A. Shutemov wrote: > > > > > Out of curiosity, do we actually have some numbers for the "non-trivial > > performance cost"? For instance for KVM usecase? > > > Dig into XPFO mailing-list discussions to find out... > I just remember that this was one of the main concerns regarding XPFO. The XPFO benchmarks measure total XPFO cost, and huge share of it comes from TLB shootdowns. It's not exactly measurement of the imapct of the direct map fragmentation to workload running inside a vitrual machine. > -Liran -- Sincerely yours, Mike.