From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753246AbcHOPAy (ORCPT ); Mon, 15 Aug 2016 11:00:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42206 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752748AbcHOPAv (ORCPT ); Mon, 15 Aug 2016 11:00:51 -0400 Message-ID: <1471273244.32433.22.camel@redhat.com> Subject: Re: [PATCH] time,virt: resync steal time when guest & host lose sync From: Rik van Riel To: Wanpeng Li Cc: Frederic Weisbecker , Ingo Molnar , LKML , Paolo Bonzini , Peter Zijlstra , Wanpeng Li , Thomas Gleixner , Radim Krcmar , Mike Galbraith Date: Mon, 15 Aug 2016 11:00:44 -0400 In-Reply-To: References: <1468421405-20056-1-git-send-email-fweisbec@gmail.com> <1468421405-20056-2-git-send-email-fweisbec@gmail.com> <1470751579.13905.77.camel@redhat.com> <20160810125212.78564dc2@annuminas.surriel.com> <1470969892.13905.120.camel@redhat.com> <20160812115803.0f26211c@annuminas.surriel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-WH7JjZe8SU0EwsiC8bG7" Mime-Version: 1.0 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 15 Aug 2016 15:00:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-WH7JjZe8SU0EwsiC8bG7 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2016-08-15 at 16:53 +0800, Wanpeng Li wrote: > 2016-08-12 23:58 GMT+08:00 Rik van Riel : > [...] > > Wanpeng, does the patch below work for you? >=20 > It will break steal time for full dynticks guest, and there is a > calltrace of thread_group_cputime_adjusted call stack, RIP is > cputime_adjust+0xff/0x130. How? =C2=A0This patch is equivalent to passing ULONG_MAX to steal_account_process_time, which you tried to no ill effect before. Do you have the full call trace? > > Subject: time,virt: do not limit steal_account_process_time > >=20 > > When a guest is interrupted for a longer amount of time, missed > > clock > > ticks are not redelivered later. Because of that, we should not > > limit >=20 > Interesting, so do we need to add a feature like lapic timer > interrrupt coalescing in kvm? There is a RTC interrupt coalescing in > qemu to handle the scenario you mentioned for windows guest, if we > need a similar feature for linux guest? Paolo, Radim? I can try it if > you think it's valuable. :) >=20 > Regards, > Wanpeng Li --=20 All Rights Reversed. --=-WH7JjZe8SU0EwsiC8bG7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJXsdkcAAoJEM553pKExN6D0WMIAJqBAl7rB2D8Cw7elp/0koWJ dlPcae51FCQxFtBMyw794zX2oRyETWT0PZGrsDwe5LgqX90fjvQQDh12RAgNLS8b hA56OxJ4zm0y5MIq+e7sHRiy/ddCjmFH/g6kpsIn1TLoMGwJ9y2YoEZOBzascolX 7SPKW0AEW/SwCaLcpkKXEy1k58ibLVuHJv2OycPr/h6w/Qrlk73RVrvG/8Afwcns DMja4cTfadUaNvj33Cx6LtrvTSx42zNkm3G9uCnHSBArEQ72myhZgZsOr1eN2Ekr C31ZiKH7xdgZjim+e+xLOZUQKRq7jNolFQqLJcz6yUIqOLIp5zJkn+9mnYuyNVg= =NOPY -----END PGP SIGNATURE----- --=-WH7JjZe8SU0EwsiC8bG7--