From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: nmi is broken? Date: Sun, 24 Apr 2011 11:46:42 +0200 Message-ID: <4DB3F182.3070006@web.de> References: <87sjtbe7fz.fsf@devron.myhome.or.jp> <877hak1t1s.fsf@devron.myhome.or.jp> <4DB3C6D3.9040703@redhat.com> <87zkngypn8.fsf@devron.myhome.or.jp> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig54E68BC1ED95A7685F347745" Cc: Avi Kivity , kvm@vger.kernel.org To: OGAWA Hirofumi Return-path: Received: from fmmailgate01.web.de ([217.72.192.221]:51139 "EHLO fmmailgate01.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756121Ab1DXJqs (ORCPT ); Sun, 24 Apr 2011 05:46:48 -0400 In-Reply-To: <87zkngypn8.fsf@devron.myhome.or.jp> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig54E68BC1ED95A7685F347745 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable On 2011-04-24 11:17, OGAWA Hirofumi wrote: > Avi Kivity writes: >=20 >>> With some debug, the cause seems to be in pit_do_work(). With the >>> following patch, NMI watchdog seems to be working correctly (if irq >>> disabled for long time, NMI watchdog can detect it). >>> >>> Is the following patch right? >> >> This would cause IRQs to be delivered even if the PIT is masked, no? >=20 > In here, mask means pit_mask_notifer()? If masked, ->pending doesn't > prevent to fire it? I'm not sure. >=20 >> Are you in fact using the PIT? Linux prefers the HPET, and in my=20 >> experience the -no-hpet option makes NMIs work. >=20 > Yes, this is old kernel (2.6.9), and is not using HPET > (CONFIG_HPET_TIMER=3Dn), using IO-APIC as NMI source (PMU seems to be > unsupported on kvm for now). >=20 > Unfortunately, -no-hpet didn't change situation. irq_stat.apic_timer_ir= qs > and nmi_count() are same while irq is disabled. Maybe it's a regression of latest NMI injection patches. This worked before? Can you check if commits c2dd554dc61173ecb6b3741b680d2ae4c245d2ba and f86368493ec038218e8663cc1b6e5393cd8e008a have any impact on your problem?= Jan --------------enig54E68BC1ED95A7685F347745 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk2z8YUACgkQitSsb3rl5xRKNgCgslUEJ0nlLW0DUhZIolxvebkG +9oAoKrivjlh+mjXSRk4rnEdF6cSQK+1 =enkq -----END PGP SIGNATURE----- --------------enig54E68BC1ED95A7685F347745--