From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [RFC PATCH 21/24] ARM: vITS: handle INVALL command Date: Tue, 6 Dec 2016 23:12:05 +0100 Message-ID: <1481062325.3445.108.camel@citrix.com> References: <20160928182457.12433-1-andre.przywara@arm.com> <0fce93d4-605b-78b9-9146-b4d65eb4e86a@arm.com> <4a8bb842-bac5-942f-ca84-d223f43ab50b@arm.com> <1481059976.3445.98.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3901939582146334230==" Return-path: Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cENyG-0004rE-GH for xen-devel@lists.xenproject.org; Tue, 06 Dec 2016 22:12:20 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Stefano Stabellini Cc: Vijay Kilari , Steve Capper , Andre Przywara , george.dunlap@citrix.com, Julien Grall , xen-devel List-Id: xen-devel@lists.xenproject.org --===============3901939582146334230== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-qXAmZ9x3iCqyhJL9F22t" --=-qXAmZ9x3iCqyhJL9F22t Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2016-12-06 at 14:01 -0800, Stefano Stabellini wrote: > On Tue, 6 Dec 2016, Stefano Stabellini wrote: > >=20 > > moving a vCPU with interrupts assigned to it is slower than moving > > a > > vCPU without interrupts assigned to it. You could say that the > > slowness is directly proportional do the number of interrupts > > assigned > > to the vCPU. >=20 > To be pedantic, by "assigned" I mean that a physical interrupt is > routed > to a given pCPU and is set to be forwarded to a guest vCPU running on > it > by the _IRQ_GUEST flag. The guest could be dom0. Upon receiving one > of > these physical interrupts, a corresponding virtual interrupt (could > be a > different irq) will be injected into the guest vCPU. >=20 > When the vCPU is migrated to a new pCPU, the physical interrupts that > are configured to be injected as virtual interrupts into the vCPU, > are > migrated with it. The physical interrupt migration has a cost. > However, > receiving physical interrupts on the wrong pCPU has an higher cost. > Yeah, I got in what sense you said "assigned", but thanks anyway for this clarification. It indeed makes the picture more clear (even just FTR) :-) Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-qXAmZ9x3iCqyhJL9F22t 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 v2 iQIcBAABCAAGBQJYRze3AAoJEBZCeImluHPubw4P/1BNJ/erucQNUe3eSb7F4NQy 4whXGkcNAjQahPBsrd8QeXRolnhkPKapeBoFGEaKbTLdTYs61RZ1UJEh6EmF1r5N vrHwWwsWlfBB6ZzsEQ6iqjuwDQxJOz5OXJ8SSwNOUNHt2Am8UVe8M5zzoVQClsaq 0aFDuCaVVEZipLnELg35u3m0SiW60VuthT4pUpNPKboGxiN2NWEqT3eeZVYqSchg I8FeIPW/fb0tMR/YMtVI9db6709PfMcwXQ631N52iZQU5cU9yX4LMGYhMnH6wXHw xHLRvIWE1ig2qbuCBQjDuYIArrCkhRsyUnkdaYHcUF8c7+CY/c70OwGTR0ylmqEa SyTRFn9bokPiLo2/B4l0bevsXnqKlmq32HaRVK3slHJ7uOHM0dvNH7OR8kkZ2fsN sNBx4ynGrG3IEa2SJvOD5EOYXcDH0HOSr7f7jSsHoHPBjN+RhUjHVTeXoD0iK/px zWT4XEpWclLHU5sobxmRsyQ9urMMlyUXZT/s1Et2dyxgrdS/RcworSiUk5wcWKTK ReBmogPfa6UM5uxvOL11x1TVT4/lhi+icqsjZZsBsJaycd/ySs/B5C+t7yTqR3hb R0u0HGQJuZvSeXfbGZW9WVS5C5h1VNC0WNk6aGE3RP1rk6OtkXAmVXpeXxgZgglX iKQJP2uFf1c2hjcmupvO =FnUm -----END PGP SIGNATURE----- --=-qXAmZ9x3iCqyhJL9F22t-- --===============3901939582146334230== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============3901939582146334230==--