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: Wed, 7 Dec 2016 01:17:14 +0100 Message-ID: <1481069834.3445.133.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> <1481063995.3445.125.camel@citrix.com> <9488db07-93fe-b8fb-7858-0f526fbbc1a3@arm.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8405011494357452213==" Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cEPvK-0006H1-VM for xen-devel@lists.xenproject.org; Wed, 07 Dec 2016 00:17:27 +0000 In-Reply-To: <9488db07-93fe-b8fb-7858-0f526fbbc1a3@arm.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Julien Grall , Stefano Stabellini Cc: Andre Przywara , Steve Capper , george.dunlap@citrix.com, Vijay Kilari , xen-devel List-Id: xen-devel@lists.xenproject.org --===============8405011494357452213== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-3QPlQNmU9eydlAnYM70l" --=-3QPlQNmU9eydlAnYM70l Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2016-12-06 at 23:24 +0000, Julien Grall wrote: > I really think we should make the vCPU migration much simpler (e.g > avoid=C2=A0 > this big loop over interrupt). In fine, if we really expect the=C2=A0 > scheduler to migrate the vCPU on a different pCPU. We should also > expect=C2=A0 > receiving the interrupt on the wrong pCPU may not happen often. >=20 This makes sense to me, but as I said, I don't really know. I mean, I understand what you're explaining but I didn't consider this before, and I don't have any performance figure. I hope I manage to explain that, if we want to take this into account during migration, as Stefano was asking about, there's a way to do that in Credit2. That's it. I'll be happy to help dealing with whatever you withing yourselves decide it's best for ARM, if it has scheduling implications. :-) And while we're here, if considering this specific aspect is not a good idea, but you (anyone!) have in mind other things that it could be interesting to take into account when evaluating whether or not to migrate a vCPU, I'd be interested to know that. After all, the advantage of having our own scheduler (e.g., wrt KVM that has to use the Linux one), is exactly this, i.e., that we can focus a lot more on virtualization specific aspects. So, really, I'm all ears. :-D Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-3QPlQNmU9eydlAnYM70l 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 iQIcBAABCAAGBQJYR1ULAAoJEBZCeImluHPuz9YQAMz8FPEXovwmB0575Q5ERiig t3L9zILLm7S4HXDSUuCT6u04CuwEaTNr2iSMZ4d4VWQrspcoRxiddwN9fgByhh1c MA11liEm5qS5A6YK7ZdfGc4x0DypcnpWK3KHT9xr+10mDZQ63MVyYDXh5k1kNvuY DXNSXhebVSzkxXSpWnkUv/1MaXYX8gRGlmLn8tTs5/j3KGfHKukj9D4lBD2JTLYM x/6CY/f0wbfIsy/uRo8Z8k7e+5H2923OQ7CPMjCe94a+sQjDT5EYnAo3V9vg0csk 22G76UAFrBCCBhBg8O6Fb6XfsYOw4kenvYEy6RW05HOsG2mOHd6LT1N/RMy7QJxO uHBYm7qqjiiWau5VvF3BIbuH7c+bPC/NBsN/0V2VTVFeCHsi9N8WJoWLhcQ86KiA IrY3mBnFIoXAbqV3ar3AAuD9HuhUga2uQ0xC4sko4a52SX13Gy2soxaqfwk+6d4e I2E7biTAf3HYVLm1KpcXFbq4xhR+h8L8Ae/fHSrdcDjIzCysQSd8nbjMwNHxvd9i X/GgO6hEdB6MsWmBwNHJFrrb/ptyKShHYCqFb9sxQdHdItgyv0pE4mIOTqu5GfXI yPWnyc2mOlAcuAG4YP871rFd4tJkVkskU3c79enRZRJxuDiE0lHlo6n01q0pUd+t +LsbSDDtiWF5BcSCF1gB =d/ak -----END PGP SIGNATURE----- --=-3QPlQNmU9eydlAnYM70l-- --===============8405011494357452213== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============8405011494357452213==--