From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: Re: KVM: x86: add module parameter to disable periodic kvmclock sync Date: Thu, 13 Nov 2014 18:57:57 +0100 Message-ID: <20141113175756.GC2958@hawk.usersys.redhat.com> References: <20141113024439.GA7402@amt.cnet> <20141113084040.GA3193@hawk.usersys.redhat.com> <20141113104401.GA4325@hawk.usersys.redhat.com> <20141113113219.GA5233@hawk.usersys.redhat.com> <20141113174658.GA6801@potion.brq.redhat.com> <5464EEBC.7080602@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Radim =?utf-8?B?S3LEjW3DocWZ?= , Marcelo Tosatti , kvm-devel To: Paolo Bonzini Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48466 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933378AbaKMR6B (ORCPT ); Thu, 13 Nov 2014 12:58:01 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sADHw1cw005706 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 13 Nov 2014 12:58:01 -0500 Content-Disposition: inline In-Reply-To: <5464EEBC.7080602@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Nov 13, 2014 at 06:47:40PM +0100, Paolo Bonzini wrote: >=20 >=20 > On 13/11/2014 18:46, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > > Yes, or add callbacks to sysfs writes that would schedule/cancel th= is > > work. (But having a for_every_vm loop is quite ugly.) > >=20 > > I'd be happy with a 'const kvmclock_periodic_sync'. > > (Having useless timers is weird if we care about latencies.) >=20 > I agree. >=20 yeah, I guess Marcelo's thought was that users may turn it off with sysfs, but once off, it'll never get to come back. In that case the original patch is perfectly fine as is. drew