From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LytPv-0001rs-P7 for qemu-devel@nongnu.org; Tue, 28 Apr 2009 15:56:35 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LytPq-0001rM-9f for qemu-devel@nongnu.org; Tue, 28 Apr 2009 15:56:34 -0400 Received: from [199.232.76.173] (port=51446 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LytPq-0001rJ-33 for qemu-devel@nongnu.org; Tue, 28 Apr 2009 15:56:30 -0400 Received: from fmmailgate02.web.de ([217.72.192.227]:45135) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LytPp-0006IW-E2 for qemu-devel@nongnu.org; Tue, 28 Apr 2009 15:56:29 -0400 Message-ID: <49F75F67.9040402@web.de> Date: Tue, 28 Apr 2009 21:56:23 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] KVM brokenness due to IO thread changes References: <49F6B2D1.8070906@web.de> <20090428125146.GB19142@amt.cnet> In-Reply-To: <20090428125146.GB19142@amt.cnet> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigB9353EE4F2561C4B8EBC2EB8" Sender: jan.kiszka@web.de List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcelo Tosatti Cc: qemu-devel This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB9353EE4F2561C4B8EBC2EB8 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Marcelo Tosatti wrote: > Jan, >=20 > On Tue, Apr 28, 2009 at 09:40:01AM +0200, Jan Kiszka wrote: >> Hi, >> >> this is a heads-up, maybe someone has some time to look into this over= >> the day: I seems like the IO thread changes caused a few regressions t= o >> the KVM mode. >> >> When I keep this feature disabled, I see strange hick-ups of the event= >> delivery mechanism, and the guest stops once in a while for a second o= r >> so. Attaching strace makes the whole process terminate early (looks li= ke >> it triggers a race in the signal handling). And when I enable the IO >> thread, I immediately get a deadlock on qemu_global_mutex. >=20 > Yes its borked. The iothread should signal the vcpu thread whenever it > wants to grab the mutex lock, because unlike kvm-userspace it does not > drop the global mutex when entering guest mode (VCPU_RUN ioctl). >=20 > Anthony will commit patches to fix that soon. Looking forward. It's far more efficient to test my infrastructure changes against the KVM mode. >=20 >> Moreover: >> CC i386-softmmu/vl.o >> /data/qemu/vl.c:4380: warning: =E2=80=98qemu_calculate_timeout=E2=80=99= defined but not used >> >> Jan >=20 > BTW, can you please review the changes made to the debugging logic in > the main loop sometime? (there's a debug_requested global now). >=20 Looks OK and works fine. Jan --------------enigB9353EE4F2561C4B8EBC2EB8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkn3X2sACgkQniDOoMHTA+nSHACeMT1ZxnvTqxo0kh548ji9jzQO QNkAnRdJeco8GcIMHYuP2BiwhDmRHHiF =/bXy -----END PGP SIGNATURE----- --------------enigB9353EE4F2561C4B8EBC2EB8--