From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v2] xen: credit1: fix tickling when it happens from a remote pCPU Date: Fri, 25 Sep 2015 10:10:45 +0200 Message-ID: <1443168645.3276.46.camel@citrix.com> References: <20150925074602.7275.97419.stgit@Solace.station> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1543303022163500969==" Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZfO5k-0008PD-Tg for xen-devel@lists.xenproject.org; Fri, 25 Sep 2015 08:10:53 +0000 In-Reply-To: <20150925074602.7275.97419.stgit@Solace.station> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu Cc: Juergen Gross , George Dunlap , Jan Beulich , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org --===============1543303022163500969== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-MLHMU7rk/DDGCVnZCSNP" --=-MLHMU7rk/DDGCVnZCSNP Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hey Wei, On Fri, 2015-09-25 at 09:46 +0200, Dario Faggioli wrote: > For instance, this can happen when an HVM domain runs in a cpupool, > with a different scheduler than the default one, and issues IOREQs > to Dom0, running in Pool-0 with the default scheduler. > In fact, right in this case, the following crash can be observed: > (XEN) ----[ Xen-4.7-unstable x86_64 debug=3Dy Tainted: C ]---- > (XEN) CPU: 7 > (XEN) RIP: e008:[] __runq_tickle+0x18f/0x430 > (XEN) RFLAGS: 0000000000010086 CONTEXT: hypervisor (d1v0) > (XEN) rax: 0000000000000001 rbx: ffff8303184fee00 rcx: > 0000000000000000 > (XEN) ... ... ... > (XEN) Xen stack trace from rsp=3Dffff83031fa57a08: > (XEN) ffff82d0801fe664 ffff82d08033c820 0000000100000002 > 0000000a00000001 > (XEN) 0000000000006831 0000000000000000 0000000000000000 > 0000000000000000 > (XEN) ... ... ... > (XEN) Xen call trace: > (XEN) [] __runq_tickle+0x18f/0x430 > (XEN) [] csched_vcpu_wake+0x10b/0x110 > (XEN) [] vcpu_wake+0x20a/0x3ce > (XEN) [] vcpu_unblock+0x4b/0x4e > (XEN) [] vcpu_kick+0x17/0x61 > (XEN) [] vcpu_mark_events_pending+0x2c/0x2f > (XEN) [] evtchn_fifo_set_pending+0x381/0x3f6 > (XEN) [] notify_via_xen_event_channel+0xc9/0xd6 > (XEN) [] hvm_send_ioreq+0x3e9/0x441 > (XEN) [] hvmemul_do_io+0x23f/0x2d2 > (XEN) [] hvmemul_do_io_buffer+0x33/0x64 > (XEN) [] hvmemul_do_pio_buffer+0x35/0x37 > (XEN) [] handle_pio+0x58/0x14c > (XEN) [] vmx_vmexit_handler+0x16b3/0x1bea > (XEN) [] vmx_asm_vmexit_handler+0x41/0xc0 >=20 This patch is a bugfix, so I think it should be included in 4.6. I'm able to trigger the above Oops pretty reliably by running an HVM guest in a cpupool that has a scheduler different than Credit (by, e.g., starting some load in the guest itself, or even just simply doing `xl shutdown' on it). It may not be the most common of the configurations, but I think it's worth. Thanks and Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-MLHMU7rk/DDGCVnZCSNP 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 v1 iEYEABECAAYFAlYFAYUACgkQk4XaBE3IOsQRBgCfYBCokT8fV4UhFbs84StjsGri A9YAn2V+gFlstkbuz19l46GCWf0vcSuf =AsQD -----END PGP SIGNATURE----- --=-MLHMU7rk/DDGCVnZCSNP-- --===============1543303022163500969== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============1543303022163500969==--