From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: Regression after "Remove support for reporting coalesced APIC IRQs" Date: Thu, 20 Jun 2013 22:10:18 +0200 Message-ID: <51C361AA.8040705@web.de> References: <20130606085352.GZ4725@redhat.com> <20130620114745.GH5832@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="----enig2CFNCUTVJJBQHHTOGENEJ" Cc: kvm@vger.kernel.org, yongjie.ren@intel.com To: Gleb Natapov Return-path: Received: from mout.web.de ([212.227.17.12]:51954 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161120Ab3FTUK0 (ORCPT ); Thu, 20 Jun 2013 16:10:26 -0400 In-Reply-To: <20130620114745.GH5832@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2CFNCUTVJJBQHHTOGENEJ Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2013-06-20 13:47, Gleb Natapov wrote: > Jan ping, are you OK with what I proposed below? >=20 > On Thu, Jun 06, 2013 at 11:53:52AM +0300, Gleb Natapov wrote: >> Hi Jan, >> >> I bisected [1] to f1ed0450a5fac7067590317cbf027f566b6ccbca. Fortunatel= y >> further investigation showed that it is not really related to removing= >> APIC timer interrupt reinjection and the real problem is that we canno= t >> assume that __apic_accept_irq() always injects interrupts like the pat= ch >> does because the function skips interrupt injection if APIC is disable= d. >> This misreporting screws RTC interrupt tracking, so further RTC interr= upt >> are stopped to be injected. The simplest solution that I see is to rev= ert >> most of the commit and only leave APIC timer interrupt reinjection. I'm not understanding the precise error yet and how __apic_accept_irq should be (properly) involved in its solution. Which code path depend on the information that the APIC is enabled? The point is that preserving the return value of __apic_accept_irq, just redefining it to "delivery_mode !=3D APIC_DM_FIXED || apic_enabled()" creates a pretty ugly interface, no? Can't we address the specific issue of the RTC at a different level? Jan ------enig2CFNCUTVJJBQHHTOGENEJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlHDYasACgkQitSsb3rl5xQ58wCaA2rOAIS2pIotLPURZLlI+92a 0yUAnRIOtofBVrxs+J17pH/PN1EqYaaE =HThI -----END PGP SIGNATURE----- ------enig2CFNCUTVJJBQHHTOGENEJ--