From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753392AbdL1MK1 (ORCPT ); Thu, 28 Dec 2017 07:10:27 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:38257 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221AbdL1MK0 (ORCPT ); Thu, 28 Dec 2017 07:10:26 -0500 Date: Thu, 28 Dec 2017 13:10:25 +0100 From: Pavel Machek To: Thomas Gleixner , kernel list Cc: mingo@redhat.com, hpa@zytor.com, x86@kernel.org, peterz@infradead.org Subject: niced tasks on SMT system Message-ID: <20171228121024.GA18152@amd> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HcAYCG3uE/tztfnV" Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HcAYCG3uE/tztfnV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! Ok, so I'm compiling, and I'd like to run a flight simulator. Flightgear normally does 20fps on my system... kinda low but playable. I have reniced make -j 5 fo kernel running. Scheduler gives 100% of one of CPUs to Flightgear (good), but the smt sibling is used by the compilation, and I'm down to 9 fps. Not good. Even with single-threaded make, I have 10-13fps. Is there way to learn which CPUs are SMT siblings? Is there way to disable SMT during runtime? Can I do something to improve Flightgear performance and still do compilation? Thanks, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --HcAYCG3uE/tztfnV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlpE3zAACgkQMOfwapXb+vLukgCdH8oR4keWZLokm+kwO41Uzo2/ mzoAoKuldQzCB1+0gSL2Sy08/3UVd27s =F8vv -----END PGP SIGNATURE----- --HcAYCG3uE/tztfnV--