From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [QEMU patch 2/2] kvm: allow configuration of tsc deadline timer advancement Date: Wed, 10 Dec 2014 19:59:53 +0100 Message-ID: <54889829.7090604@redhat.com> References: <20141210162317.370733848@amt.cnet> <20141210162420.218207164@amt.cnet> <54887C61.80008@redhat.com> <20141210170405.GA19952@amt.cnet> <54887E3F.4030904@redhat.com> <20141210172712.GA20568@amt.cnet> <54888307.6020407@redhat.com> <20141210173554.GB21295@amt.cnet> <5488892C.7010606@redhat.com> <20141210183905.GA31236@potion.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Marcelo Tosatti , kvm@vger.kernel.org, qemu-devel@nongnu.org, Luiz Capitulino , Rik van Riel To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Return-path: Received: from mail-wg0-f53.google.com ([74.125.82.53]:58903 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932501AbaLJS77 (ORCPT ); Wed, 10 Dec 2014 13:59:59 -0500 Received: by mail-wg0-f53.google.com with SMTP id l18so4443210wgh.40 for ; Wed, 10 Dec 2014 10:59:58 -0800 (PST) In-Reply-To: <20141210183905.GA31236@potion.brq.redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/12/2014 19:39, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > 2014-12-10 18:55+0100, Paolo Bonzini: >> Well, my preferred choice would be automatic adjustment with a modul= e >> parameter. If we need manual tuning, per-CPU would be my choice, bu= t >> automatic is nicer anyway. :) >=20 > I agree with Paolo, and think it would be better not to touch QEMU ..= =2E > it makes little sense to migrate this value and it is probably going = to > be quite similar on every CPU, so a writeable module parameter is a > better starting point. (We can always turn it into a nightmare later= =2E) Ok, let's start with a simple module parameter, similar to what PLE use= d to have. We can use that to play with kvm-unit-tests. Paolo