From: "Jan Beulich" Subject: Re: [PATCH][RFC] remove PV/x86 warnings (time wentbackwards) Date: Thu, 11 Dec 2008 10:31:43 +0000 Message-ID: <4940FA1F.76E4.0078.0@novell.com> References: <20081211080251.02F901808C@m021.s.css.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Atsushi SAKAI , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org >>> Keir Fraser 11.12.08 10:22 >>> >On 11/12/2008 08:02, "Atsushi SAKAI" wrote: > >>=20 >> This patch intends to remove warnings for Time went backwards >> (negative delta) like follows. >> =3D=3D=3D=3D=3D=3D=3D=3Dfrom Xen BZ 195 >> Timer ISR/0: Time went backwards: delta=3D-10048465 cpu_delta=3D9951535 >> shadow=3D706605145 0: 71640046095 >> =3D=3D=3D=3D=3D=3D=3D=3D > >That might be considered skirting around the problem. Are users still = seeing >this with xen 3.3 and xen unstable? Unfortunately yes, but rather seldom these days. We just got a fresh report about a larger IBM system suffering from it - while the initial = report they sent had hundreds of milliseconds in them, the most up-to-date one we have shows that it's just a few milliseconds above the -10ms boundary. So far I haven't been able to figure what causes this. Jan