From: Olaf Hering Subject: Re: [PATCH v3] new config option vtsc_tolerance_khz to avoid TSC emulation Date: Tue, 20 Mar 2018 10:48:34 +0100 Message-ID: <20180320104834.335c2a41.olaf@aepfle.de> References: <20180306104133.22106-1-olaf@aepfle.de> <20180312101508.4a9444c2.olaf@aepfle.de> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7548790046253250026==" Return-path: In-Reply-To: <20180312101508.4a9444c2.olaf@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Andrew Cooper Cc: Stefano Stabellini , Wei Liu , George Dunlap , Tim Deegan , Ian Jackson , Marek =?UTF-8?B?TWFy?= =?UTF-8?B?Y3p5a293c2tpLUfDs3JlY2tp?= , xen-devel@lists.xen.org, Julien Grall , Jan Beulich , Daniel De Graaf List-Id: xen-devel@lists.xenproject.org --===============7548790046253250026== Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/he0z_07eZj9BsQ/1sqf0n7p"; protocol="application/pgp-signature" --Sig_/he0z_07eZj9BsQ/1sqf0n7p Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable So, how do we address the performance regression fixed by this patch? Olaf Am Mon, 12 Mar 2018 10:15:08 +0100 schrieb Olaf Hering : > Am Tue, 6 Mar 2018 11:07:54 +0000 > schrieb Andrew Cooper : >=20 > > > Add a new domctl XEN_DOMCTL_set_vtsc_tolerance_khz to adjust the > > > tolerance value of a running domU that is supposed to be migrated. = =20 > > Please can we not proliferate the domctls. > > This looks like it should be part of the set_tsc_info hypercall, not a > > separate hypercall. =20 >=20 > How should this approach be implemented? To me it looks like set_tsc_info > should be called only once for a not-yet-active domU, but I'm not familiar > with timekeeping. > If it can be just called once, and there should be a way to adjust the=20 > tolerance value, then XEN_DOMCTL_settscinfo would need to be changed to=20 > have subcommands. --Sig_/he0z_07eZj9BsQ/1sqf0n7p Content-Type: application/pgp-signature Content-Description: Digitale Signatur von OpenPGP -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQSkRyP6Rn//f03pRUBdQqD6ppg2fgUCWrDY8gAKCRBdQqD6ppg2 fshoAJ9lXb9CjnheILarX1JUGvsEJ1LveQCeIiItQ/mgpBPKLVgPSVh4Hy7x/M0= =CjNW -----END PGP SIGNATURE----- --Sig_/he0z_07eZj9BsQ/1sqf0n7p-- --===============7548790046253250026== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0 cy54ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== --===============7548790046253250026==--