From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753438AbaFDNzJ (ORCPT ); Wed, 4 Jun 2014 09:55:09 -0400 Received: from casper.infradead.org ([85.118.1.10]:46914 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752513AbaFDNzG (ORCPT ); Wed, 4 Jun 2014 09:55:06 -0400 Date: Wed, 4 Jun 2014 15:54:58 +0200 From: Peter Zijlstra To: Daniel Lezcano Cc: Andy Lutomirski , umgwanakikbuti@gmail.com, mingo@kernel.org, tglx@linutronix.de, nicolas.pitre@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] sched,trace: Add a tracepoint for remote wakeups via polling Message-ID: <20140604135458.GN30445@twins.programming.kicks-ass.net> References: <538F186A.2060801@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2roH7liMbLpZFZp3" Content-Disposition: inline In-Reply-To: <538F186A.2060801@linaro.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --2roH7liMbLpZFZp3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 04, 2014 at 03:00:26PM +0200, Daniel Lezcano wrote: > On 06/04/2014 02:29 AM, Andy Lutomirski wrote: > >Remote wakeups of polling CPUs are a valuable performance > >improvement; add a tracepoint to make it much easier to verify that > >they're working. > > > >Signed-off-by: Andy Lutomirski >=20 > I don't think this trace makes sense. The polling state is x86 only and t= his > trace is in the generic code. Not so, there's PPC using it someplace (ISTR its doing a polling amortization of the idle hypercall or somesuch) and there's archs that have no other idle means that polling, as well as some for which its optional. There are indeed archs, like arm, that only do the WFI thing, and for those this is indeed all a NOP. --2roH7liMbLpZFZp3 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTjyUyAAoJEHZH4aRLwOS6g40QAKU3BFQ1GiUTctfo1nG3hhfF IMwT0TH+ljrcRx9rXk0mMpAON5hOWjYRTOJgL3Sp3eXtzEE2U5PQKnXQt+/2Y1f7 tc62laHiEq5+7azv865TGQ2B1EUgRUAjl4U3DXa8VtSBh7Hkyu2DXTPbnWasoc+I PHdpzNM+rQnbLm5AR+p4GcqrF3ZlfkAy4x4kqdujUGalOeVKjthW/tejyYqsTuEM xHDEeMmPtkzY1THJriOUcv5/OBr9Syg/LetpxDpcQtqTQnWGdplS6nUlTHj1/P/i 0UaMUCB49kmiDMiOHzNcxbgY+1a57jNxS2BXHjqYh/50zJahHG/8nO6eyFn61okv DAzRoFeqYqtpKB5yJyRK9e7SSJwmdHg/7XJIWcYmNfHFk+S2OZGLvK6sU2+uJoGf uII4NCTDDGm5z/DU8pPn6sIpfYj529IaFdB09p3OnuwDa9x3JZnXljcarL+QXPOJ J7GO6HPtauKynCXqF34CtOCUuE4z/qDAUDFkuczT6/JH2L8wBqrkdLZdPR6/lM/D JAIPLFIYZaKzg6kOGEPwZDPKV3o2xSL10+uCwHgF9JZhOUFDdnueNwsnj+mVaCrw tvZScSI76HY4g1+6Zogou8Ri0Fm0Ua7DF6h4flfoirVpXx5YiGHEh5gcnfGjf5aC 5fpgHdDExJLlfiTG8MQF =F5bB -----END PGP SIGNATURE----- --2roH7liMbLpZFZp3--