From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752030AbeERMr6 (ORCPT ); Fri, 18 May 2018 08:47:58 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751112AbeERMrz (ORCPT ); Fri, 18 May 2018 08:47:55 -0400 Date: Fri, 18 May 2018 15:47:53 +0300 From: "Michael S. Tsirkin" To: Paolo Bonzini Cc: Eduardo Habkost , linux-kernel@vger.kernel.org, Radim =?utf-8?B?S3LEjW3DocWZ?= , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH] kvm: rename HINTS_DEDICATED to KVM_HINTS_REALTIME Message-ID: <20180518154721-mutt-send-email-mst@kernel.org> References: <1526568841-35372-1-git-send-email-mst@redhat.com> <20180517184658.GA1543@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 18, 2018 at 11:41:23AM +0200, Paolo Bonzini wrote: > On 17/05/2018 20:46, Eduardo Habkost wrote: > > My understanding of the original patch is that the intention is > > to tell the guest that it is very unlikely to be preempted, so it > > can choose a more appropriate spinlock implementation. This > > description implies that the guest will never be preempted, which > > is much stronger guarantee. > > > > Isn't this new description incompatible with existing usage of > > the hint, which might include people who just use vCPU pinning > > but no mlock? > > If you use hugetlbfs and vhost-user you don't really need mlock for the > QEMU process, do you? The QEMU process is not doing much in that case > and hugetlbfs gives you pinned memory automatically. > > Paolo Same with PCI device passthrough: VFIO pins all guest memory right now. -- MST