From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH v12] tolerate jitter in cpu_khz calculation to avoid TSC emulation Date: Fri, 8 Mar 2019 20:29:07 +0100 Message-ID: <20190308202907.56f7609a.olaf@aepfle.de> References: <20190308192059.24610-1-olaf@aepfle.de> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8917197907345791135==" Return-path: Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1h2LBH-0008At-BJ for xen-devel@lists.xenproject.org; Fri, 08 Mar 2019 19:29:19 +0000 In-Reply-To: <20190308192059.24610-1-olaf@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: xen-devel@lists.xenproject.org Cc: Andrew Cooper , Wei Liu , Jan Beulich , Roger Pau =?UTF-8?B?TW9ubsOp?= List-Id: xen-devel@lists.xenproject.org --===============8917197907345791135== Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/C_EgcOe5OEDWTQO58vZv.Bu"; protocol="application/pgp-signature" --Sig_/C_EgcOe5OEDWTQO58vZv.Bu Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Am Fri, 8 Mar 2019 20:20:59 +0100 schrieb Olaf Hering : > To reiterate the second paragraph: if a domU uses TSC as primary clock > source, it is expected that it runs NTP to cover for the resulting > drift. Therefore this change does no need a knob to turn it on or off. One interesting aspect is: the xenlinux based kernels report clocksource=3D= tsc, but I think there was no explicit requirement to run NTP in domU. There was even that 'independent_wallclock' knob. Why is that? Olaf --Sig_/C_EgcOe5OEDWTQO58vZv.Bu Content-Type: application/pgp-signature Content-Description: Digitale Signatur von OpenPGP -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQSkRyP6Rn//f03pRUBdQqD6ppg2fgUCXILCgwAKCRBdQqD6ppg2 foRNAKDMCS7YMdNmJ9rk54gPrwkqRarCbwCgh31Y2Y91St/C0GKB029DDGjPX88= =iyfz -----END PGP SIGNATURE----- --Sig_/C_EgcOe5OEDWTQO58vZv.Bu-- --===============8917197907345791135== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0 cy54ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== --===============8917197907345791135==--