From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [for-4.8 PATCH] xen: credit2: make runqueues be per-socket by default. Date: Tue, 29 Nov 2016 12:33:24 +0100 Message-ID: <1480419204.3178.36.camel@citrix.com> References: <148041661626.16498.9321899625033399324.stgit@Solace.fritz.box> <148041702351.16498.17129591426095525570.stgit@Solace.fritz.box> <20161129111425.GS11640@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8423126401329897652==" 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 1cBgfE-0006tl-Op for xen-devel@lists.xenproject.org; Tue, 29 Nov 2016 11:33:32 +0000 In-Reply-To: <20161129111425.GS11640@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Wei Liu Cc: George Dunlap , xen-devel@lists.xenproject.org, Anshul Makkar List-Id: xen-devel@lists.xenproject.org --===============8423126401329897652== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-kYNjQg32nwfDRIgmQPyl" --=-kYNjQg32nwfDRIgmQPyl Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2016-11-29 at 11:14 +0000, Wei Liu wrote: > On Tue, Nov 29, 2016 at 11:57:03AM +0100, Dario Faggioli wrote: > Strictly speaking, this is not necessary for 4.8 because even though > the > default configuration is not optimal, there is a simple way to change > it. >=20 Absolutely true. > On the other hand, because credit2 is declared supported in this > release, it is better to have a sensible default setting for credit2. >=20 Exactly. > The risk is that changing the default value would cause osstest to > discover bugs in the scheduler logic, hence blocking the release. But > overall I think the chance is low, but Dario can you please state to > what extend did you test this patch? >=20 I've tried to state that in the cover letter: https://lists.xen.org/archives/html/xen-devel/2016-11/msg02616.html In some more details, it is _months_ that I and Anshul run benchmarks with Credit2 running in this configuration. It's months that, all the time that I boot my test box, either to do Credit2 related development and testing, or completely unrelated things (e.g., recently, when testing the new Fedora 25 as HVM and PV guest), I use Credit2 in this configuration. George has done some runs of his schedbench suite with this configuration (to compare Credit1 vs Credit2 per-core vs Credit2 per- socket). So, if you ask me "how much is this tested", my answer would be "really really really a lot". :-) Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-kYNjQg32nwfDRIgmQPyl 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 iQIcBAABCAAGBQJYPWeEAAoJEBZCeImluHPu+LoQAM7cqxqHt326MOaUM9LgmK7E IQlxSq46mvypuSdrBAJ6Co2SUliBqfld8KOzicVmO7UaWZR9OHCLSCTNmjTaqGsF 8+JcRNE/c+VK6X/ZUgU17h1Kj6Sl/z5QhHCMqv50qYykOIxUl+zapdHKKTJCpopX Q3iWqzpTviI4TdIxCAmOjefmUxgeBydMDgz9gZa1oG5NaRwnDXpUOw5R/BavWuTZ iAxpogY22kVBPKVnk2P7S0DEmgeDoOWDIRWMrOHTtyqDybMvY/eo5CqvuOoIcnki 1vQSsLABWCeFrF7C/ojXVWubvegqNg7lgfp4OZt0WYu6/q7p6fWPp+MmpPOWPAKA 7bzuaQqhQVG8APdkB85Sp3HIvh8DyxVDP+h94n1SkwuM9KIUCJH157VoJeBXfsno 79ECTipojuWjRtkZImCP+aSo3uJwosgwDFIbSilwI05Rh+iQwdUZUl4rumcmwQp8 ccfxDnkiQ9ctn2TJxFsMZxANDtvYQsIS5YhL2F9DvM6NcNvtcjgFjuwX9DyxoLVL KAFM77iFe4b7H9K3b/tGTDh3RVMIkziSlQc55O5yEbCcRI7zpYicku1/06snFSbz Z3YfHEx6ypG3J2WzzUwoUW8IYy3rTYMrZWeUr0EIFx1BY0ZBxE2/+fqxrVO0bL/v VJSEGF63ErHt65fRWujP =92en -----END PGP SIGNATURE----- --=-kYNjQg32nwfDRIgmQPyl-- --===============8423126401329897652== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============8423126401329897652==--