From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: [PATCH] cpuidle: use high confidence factors only when considering polling Date: Fri, 18 Mar 2016 22:17:30 -0400 Message-ID: <1458353850.14723.57.camel@redhat.com> References: <20160316121400.680a6a46@annuminas.surriel.com> <10828426.sI6CaBvZhk@vostro.rjw.lan> <000701d180df$e8a14340$b9e3c9c0$@net> <003301d18144$87bb8df0$9732a9d0$@net> <20160318173551.675ff6e5@annuminas.surriel.com> <1458352411.14723.55.camel@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-wBVC13u82M5mMwBDzaJV" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:39068 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753795AbcCSCRe (ORCPT ); Fri, 18 Mar 2016 22:17:34 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Doug Smythies , "Rafael J. Wysocki" , Viresh Kumar , Srinivas Pandruvada , "Chen, Yu C" , "linux-pm@vger.kernel.org" , Arto Jantunen , Len Brown --=-wBVC13u82M5mMwBDzaJV Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, 2016-03-19 at 03:06 +0100, Rafael J. Wysocki wrote: > On Sat, Mar 19, 2016 at 2:53 AM, Rik van Riel > wrote: > >=C2=A0 > > The kernel test robot also showed over 6% improvement in (IIRC) > > the wikibench test, with polling being done a little more often. > >=20 > > Other parts of the kernel do pretty much anything for 2% extra > > performance, so if we can find a way to preserve that 6%, without > > hurting power usage significantly, I suspect it may be worthwhile. > Well. OK.=C2=A0=C2=A0That is a worthy goal, but things in this thread loo= k a > bit > too ad-hoc to me to be honest. >=20 > I'd like to take one step at a time and in such a way that > improvements are actually confirmed in every step. >=20 > Does this sound reasonable? >=20 > If so, I first would like to restore the energy consumption in the > Doug's case at least to the level from before commit a9ceb78bc75c > (cpuidle,menu: use interactivity_req to disable polling).=C2=A0=C2=A0That= 's > what > I'd like to do for 4.6 and possibly before the merge window is over. >=20 > After 4.6-rc1, in the 4.7 cycle, we can think about improving > performance here and maybe sacrificing some energy for that, but in a > controlled way as I said above. >=20 > What do you think? That sounds perfectly reasonable to me. Count me in for any efforts to improve performance with the cpuidle code, and hopefully allow more people to enable c-states on their servers. --=20 All Rights Reversed. --=-wBVC13u82M5mMwBDzaJV 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 iQEcBAABCAAGBQJW7La6AAoJEM553pKExN6DXK0IAJeocBgd47bTjZWY+T9uGKNi QuvNpLgdxGOP5Gb2NympNFRr4pTE9A3pj6m7uPuJbcuk+pcARu19wUftnVH+rQXx 4iN5yBbWD2Fltfif/H1KScQnq25QPV7pX1TjJuB6AtQQhOVFp764Q9XOYRquUNKj 18JcxC0DpDZokoUwjKa7lpG9Fvrf2Pjv038a9Xv8M6AFrLfh89J12hlUKwNVIQRm ymU5hDtoXVjcSQmhnESGb/7h/EWRJt434ywmHq0cEuRF2x6Vj/eTB5V6ctT2lNYk yiQvLaQONPtq6gq+VmdQNoCeCRIf4TpED3FMLFueOHO88z+IxDT4zNVFNm74vZc= =+qMj -----END PGP SIGNATURE----- --=-wBVC13u82M5mMwBDzaJV--