From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 5E3206B0006 for ; Tue, 6 Mar 2018 09:09:50 -0500 (EST) Received: by mail-wr0-f200.google.com with SMTP id j28so13152973wrd.17 for ; Tue, 06 Mar 2018 06:09:50 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id q5sor1945922edj.54.2018.03.06.06.09.48 for (Google Transport Security); Tue, 06 Mar 2018 06:09:48 -0800 (PST) Date: Tue, 6 Mar 2018 17:09:32 +0300 From: "Kirill A. Shutemov" Subject: Re: [RFC, PATCH 19/22] x86/mm: Implement free_encrypt_page() Message-ID: <20180306140932.bdll5vh6qzyydqg4@node.shutemov.name> References: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> <20180305162610.37510-20-kirill.shutemov@linux.intel.com> <20180306085412.vkgheeya24dze53t@node.shutemov.name> <64d11e65-76b7-4e70-553c-009263b50a1c@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <64d11e65-76b7-4e70-553c-009263b50a1c@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Kirill A. Shutemov" , Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Tom Lendacky , Kai Huang , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, Mar 06, 2018 at 05:52:44AM -0800, Dave Hansen wrote: > On 03/06/2018 12:54 AM, Kirill A. Shutemov wrote: > >> Have you measured how slow this is? > > No, I have not. > > It would be handy to do this. I *think* you can do it on normal > hardware, even if it does not have "real" support for memory encryption. > Just don't set the encryption bits in the PTEs but go through all the > motions of cache flushing. Yes, allocation/freeing and KeyID interfaces can be tested with MKTME support in hardware. I did most of my testing this way. > I think that will help tell us whether this is a really specialized > thing a la hugetlbfs or whether it's something we really want to support > as a first-class citizen in the VM. I will benchmark this. But not right now. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org