From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric B Munson Subject: Re: [PATCH 0/5 V5] Avoid soft lockup message when KVM is stopped by host Date: Wed, 14 Dec 2011 09:54:07 -0500 Message-ID: <20111214145407.GA4075@mgebm.net> References: <1323116344-17911-1-git-send-email-emunson@mgebm.net> <4EDF7B0D.4060001@redhat.com> <20111214121622.GB18317@amt.cnet> <4EE8B53C.6070502@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2fHTh5uZTiUOsy+g" Return-path: Received: from oz.csail.mit.edu ([128.30.30.239]:39919 "EHLO mail.mgebm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840Ab1LNOyK (ORCPT ); Wed, 14 Dec 2011 09:54:10 -0500 Content-Disposition: inline In-Reply-To: <4EE8B53C.6070502@redhat.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Avi Kivity Cc: Marcelo Tosatti , mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, ryanh@linux.vnet.ibm.com, aliguori@us.ibm.com, jeremy.fitzhardinge@citrix.com, levinsasha928@gmail.com, Jan Kiszka , kvm@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org --2fHTh5uZTiUOsy+g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, 14 Dec 2011, Avi Kivity wrote: > On 12/14/2011 02:16 PM, Marcelo Tosatti wrote: > > > Having this controlled from userspace means it doesn't work for SIGST= OP > > > or for long scheduling delays. What about doing this automatically > > > based on preempt notifiers? > > > > Long scheduling delays should be considered hangups from the guest > > perspective. >=20 > Why? To the guest it looks like slow hardware, but it will interpret it > as a softlockup. >=20 > > About SIGSTOP, that is a corner case. Unsure if its even properly suppo= rted=20 > > by QEMU. >=20 > It works from my experience. >=20 > --=20 > error compiling committee.c: too many arguments to function >=20 And if the soft lockup warning is a concern here, we can have a SIGCONT han= dler set the flag the same way qemu stop/cont does. --2fHTh5uZTiUOsy+g Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJO6LiPAAoJEKhG9nGc1bpJnqMP/3RQ6LT1oRyUGhYNom1tcocN HxCTwIE2cMcbNliVCnMIotG8ZWBLrMBwmuq+4bdlSn4EG0e9mg3FxWgqJndysux7 2Xy+NS3+/Q/TgZ2gwtduUk0MJxIci4MmBIqGdUjwy7BaiwEjJ0pLLy0q3Zlizjcj WuSQwJmtXQ9SwPvXDv/llGPhfc/aDjaaeEYmy81t6lSZnizkF3210Vn0u5ALDFbx VTXxsiis/KwgOpM3A81T9VO4XeO4LrZ0OV/vDLyXIkXCN3O+p512DeWq4nTl5KGU q0rhXxnH+NeczSqNI6J/sRTwvw4odnAN1fYyjjie3ZGPNx8/fLE4oGm40UStaRbN w+TuYjse+ChNuT7gZErb6eUrBotMxpxUqUwCxGDfY2o1uRdQcYoivOnrtux9Wsls j9pzBD0a5DXBofuKgjwLLvVLkEmWd/K6WRdjtvDdbCl4KJKGl7wZn8Zn6qoX/Kgr PR+VK3N4z11Coh1s0Oe1YrMhvHzwiarNhluZzmsI2bgZxyZXzMNBDsvpJmr1XDpe hOodUd24ONC9Poxj8LndAO63KfXHSrgs1STF+LjBOb4f5Ao1JqChpUBnqXwsWJz+ M6QVDhSAGjt9GgmATwucyiWIhVC4SjI49UkG4AMEeFnbR2eMIJULfC9B9NlHnB1c 9yees0YjkRmfxZFKeuJX =OZOd -----END PGP SIGNATURE----- --2fHTh5uZTiUOsy+g--