From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: RTDS with extra time issue Date: Mon, 12 Feb 2018 11:17:18 +0100 Message-ID: <1518430638.16540.17.camel@suse.com> References: <762ccb02-b758-1636-fddc-f4e6a3ca19d0@epam.com> <1518182334.5019.15.camel@suse.com> <39c08b88-c951-2779-34f6-31e4b6c0dd0f@epam.com> <1518189527.5019.28.camel@suse.com> <1518221652.4261.33.camel@suse.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7569635971859497917==" Return-path: Received: from all-amaz-eas1.inumbo.com ([34.197.232.57]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elBBK-0000kr-EG for xen-devel@lists.xenproject.org; Mon, 12 Feb 2018 10:17:54 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Meng Xu Cc: xen-devel , Andrii Anisov List-Id: xen-devel@lists.xenproject.org --===============7569635971859497917== Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-ZoSjadYf7D9+lfpv+ZxZ" --=-ZoSjadYf7D9+lfpv+ZxZ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2018-02-09 at 23:53 -0500, Meng Xu wrote: > >=20 > > Perhaps Meng has some more ideas on this as well. :-) >=20 > If the RT VCPU has only one RT task on it, we can synchronize the > release time of the VCPU and that of the RT task. In other words, the > release offset of both the VCPU and the RT task are the same in terms > of the wall clock. Then we can assign the task's parameter to the > VCPU > and guarantee the task has no deadline miss if the VCPU has no > deadline miss. > However, this observation only works when the assumption that one > VCPU > has only one task in the RT domain. I'm not sure how practical it is > because the observation cannot be generalized for multiple tasks on > one VCPU. >=20 > Andrii and Dario, > Do you think the assumption that one VCPU runs only one RT task is > reasonable in practice? > If it is, is there some use cases for this assumption? >=20 Well, I'll let Andrii reply, but honestly, I don't think it is. See, for instance, the fact that DomR has only 1 vCPU, so I find it unlikely that the only thing that run there is *just* *one* real-time task. :-/ Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Software Engineer @ SUSE https://www.suse.com/ --=-ZoSjadYf7D9+lfpv+ZxZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEES5ssOj3Vhr0WPnOLFkJ4iaW4c+4FAlqBaa4ACgkQFkJ4iaW4 c+5GSxAAl4J24Spln8LaHHukpLBJjjOfYaMqmYcLlKVM+nb4uE2DAv21kOxTYDbz AoUQDBwEvOXUsst3/Asbo0P6OaklGxfzdLMPggDoez5PAPzl7uvm1YrjRgR20Dvz hBeSmSGl7eWBsrPv+vUQ6HcPLGkI24sbvCfUBfqBQB1Rb5L86MZl734ROtYYyWsI 5Yt6g5/xd6MVoMXFibWgdWx0mvDpMnBgeoZ6dUawefuGEZ97n11pbrM/oSshwJEd z3Vf0QnDQhFFHZcr6nQZH96EVCRd01yQO37oP93ubU9bK8Xonx/CpVdf33dYbY/e F7EC9wpkbiZyz6lVD7yv5SLWXjN7vCyJsSJ1yEzLm7IdjhuQ8T8fGei2VmXlS1r6 6ykJZ4ZWDnmG82iwnefCQH/yWfu184UqxUEkwEfyF/SowfLlnhlPBWf80rj09TBu kpAsRZfZeXZWCUyYUFF91BW8/Jk8aGWfz6Ocmn7ZLVVImnoj4i3/3qHG5qDku9wY tH6GBo1IMFU4S8jbOzVLPepzNsg6V6d+BFAoFQaMTTwPzWon+m5oJoYknftRO/TT cnj96b2pgk/XaiQ1HhTEV0LXtgmvgfLAwMQphiZJNi4BK1FjGYtrIixxip9EntUJ t5qx2hLPdjVlVDm+7FGNRI6fguGe+AspKx3Q7Awr5yYj6vCUmak= =Y+AG -----END PGP SIGNATURE----- --=-ZoSjadYf7D9+lfpv+ZxZ-- --===============7569635971859497917== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0 cy54ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== --===============7569635971859497917==--