From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: Xen on ARM IRQ latency and scheduler overhead Date: Sat, 18 Feb 2017 01:47:33 +0100 Message-ID: <1487378853.6732.106.camel@citrix.com> References: <1486716022.3042.112.camel@citrix.com> <1487247614.6732.45.camel@citrix.com> <1487329361.6732.76.camel@citrix.com> <3672df49-6353-5d03-ab0b-1143ffdf0822@arm.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3431324790972545367==" Return-path: 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: edgar.iglesias@xilinx.com, george.dunlap@eu.citrix.com, Julien Grall , nd@arm.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org --===============3431324790972545367== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-qrT6J7FYDXZYc5slaBBn" --=-qrT6J7FYDXZYc5slaBBn Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2017-02-17 at 16:02 -0800, Stefano Stabellini wrote: > On Fri, 17 Feb 2017, Stefano Stabellini wrote: > >=C2=A0 > > NODEBUG vwfi=3Didle credit2 fix cpumasks 4000 2370=09 > > 4500 3350 > > NODEBUG vwfi=3Didle credit1 fix cpumasks 3220 2180=09 > > 4500 4320 >=20 > Actually those are still the old numbers, sorry!=20 > Yeah, I know, I've done the same sooo many times! :-P > I didn't update the xen > binary properly. These are the new numbers: >=20 > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0AVG =C2=A0=C2=A0=C2=A0=C2=A0MIN =C2=A0=C2=A0=C2=A0=C2= =A0MAX > =C2=A0=C2=A0=C2=A0=C2=A0WARM MAX > vwfi=3Dsleep credit2 fix cpumasks 5910 5800 8520=09 > 6180 > vwfi=3Dsleep credit1 fix cpumasks 4900 4810 6910=09 > 4980 > vwfi=3Didle=C2=A0=C2=A0credit2 fix cpumasks 2800 1560 4550=09 > 4200 > vwfi=3Didle=C2=A0=C2=A0credit1 fix cpumasks 2800 1610 3420=09 > 1770 >=20 > The difference between credit2 and credit1 is smaller now. In fact > it's > zero, when vwfi=3Didle.=20 > Ok, cool. > However, with vwfi=3Dsleep, the larger MAX value is > a bit worrying. >=20 I still think this may be due to the fact that you never stop Credit1's tick on ARM, which means that, when on Credit1, the system is a lot more "alive" (e.g., if we were on x86, I'd have said it'd spend less time in deep C-states, and things like that). And yes, I still owe you a patch for disabling it. I'm working on that one. :-) Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-qrT6J7FYDXZYc5slaBBn 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 iQIcBAABCAAGBQJYp5mmAAoJEBZCeImluHPuMF4QANVZSDKlXB1bBAdenYjbyW+1 p96Urqo9ZPii60DxIrkguGTTn9gS+2Zu8glUX0IBI/upfIFpqZ0JzmZlMVD3zxLA p1k/HatCyZm+M8PvVyHHFq59E2VOxc5xuzEq1/JC2IvuFwO7eBVZjcIDmv5S8mjZ YDGR5olNW5ycBy42/QloqWQtUGN0F8dO/0T8z/+/68ylvpQmDGpIAfuzFXpsREf7 35Mts+7U6+DaoCFEjKNC2UOxZ/lam3BtFBwrLB0IPua+WXHOwsE5TbL6osA4omsC GXEqUcIvG4oQWcqgKYJSUUMnU7PGOIFVbvjbcLLPz2KEH0D2CrLm30RARl1v8PgK 936jbL9rAV74MuWcRYjNcNme1ykzN2aYWiTQybKp6PD7Ku2LAKngztOVx6CBUO0W 7N6jHYaDSpMnBh75F2pvRsUPs4ev/pWY+jrHSUzr6CA2YhYjaYw/p2FDFof7Q++9 cpeJFIrdme97bN/eUDxFajGzhtbaDalTQ+3IPRGB0To0jeq6ApME18t1SiJ8CRta H/6yyqxlhm/ysaV73A26OIfGcbo18624K+gE00Hc1WqvgEPVtxE9Wjb5o6AFBW8j x2VMwMHpVfrnOQ+/MoXbdgj7VUSCeNUN3Y+9gNE5Px4gj3CVkeCcCduKmEgTk2Qx jq1njADQUVdyEY18oSRs =td3w -----END PGP SIGNATURE----- --=-qrT6J7FYDXZYc5slaBBn-- --===============3431324790972545367== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============3431324790972545367==--