From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754230AbaESKyZ (ORCPT ); Mon, 19 May 2014 06:54:25 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:44250 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754203AbaESKyX (ORCPT ); Mon, 19 May 2014 06:54:23 -0400 Date: Mon, 19 May 2014 12:54:04 +0200 From: Peter Zijlstra To: Mike Galbraith Cc: paulmck@linux.vnet.ibm.com, Paul Gortmaker , linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Ingo Molnar , Steven Rostedt , Thomas Gleixner Subject: Re: [PATCH] sched/rt: don't try to balance rt_runtime when it is futile Message-ID: <20140519105404.GZ30445@twins.programming.kicks-ass.net> References: <1400080115-12339-1-git-send-email-paul.gortmaker@windriver.com> <20140514154459.GE4570@linux.vnet.ibm.com> <1400123931.5175.38.camel@marge.simpson.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HditFSw+SJxJh6AP" Content-Disposition: inline In-Reply-To: <1400123931.5175.38.camel@marge.simpson.net> 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 --HditFSw+SJxJh6AP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 15, 2014 at 05:18:51AM +0200, Mike Galbraith wrote: > On Wed, 2014-05-14 at 08:44 -0700, Paul E. McKenney wrote: >=20 > > In practice, not sure how much testing CONFIG_NO_HZ_FULL=3Dy has receiv= ed > > for -rt kernels in production environments. >=20 > I took 3.14-rt out for a quick spin on my 64 core box, it didn't work at > all with 60 cores isolated. I didn't have time to rummage, but it looks > like there are still bugs to squash.=20 >=20 > Biggest problem with CONFIG_NO_HZ_FULL is the price tag. It just raped > fast mover performance last time I measured. Syscall entry and exit times are through the roof with it. So anything doing loads of syscalls will suffer badly. --HditFSw+SJxJh6AP Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTeeLMAAoJEHZH4aRLwOS6KCAP/ilJRsxFkR9rQNK6LanTx6S3 RbvdAmgdvRTvELyJTT2QzGyBo/GNz/f4LbXnLd37iGQwBEUY8eLEpLuUVKPXPAkk VuEDsQy/Y8K2GOlJ4E0D8ZHa0/VFpcWvJrFE6fhbHioq2E0EOU/AiliKU74u+y2j XufiDl4xo8cH36tO2pM5VNEvM0p/0KxwELJNB5RUpdhxS/H8o2QoEfwlMY45WTzW Uss/jxt/FfB9xXLBozaQUkSr5fC+ZpyXrGkT7EIasCgp6GfH55iz6JvSq1fn/Qtb xAMsxrAMHkr3CMejUQaoJ9A8S6IrBcS7Cn8nkFWwdun98EHXJnh9Cx9G2uKzeTDu 2+Nf/mZqDspncKSt+TmhOB2e7Xs8SXOfpErtFPdLyQeubH1QgyY7jSvYryGCNuP9 b94II8bPIfp2OpAThpDhzVqNhw3oSGPiiZom8CZMKSs0uSq38Oqqn7iaOLueSaeC Yth3U4+bmNQk858W18whwZP6ShGXLrGcuIVSTXd/zLI1GB+iCtxYlJ2j/oPmFgfg TAsX8MXY5FVVN9ffoIQLMfHScMVt4rOdvxNGFF3kmP+RgS0+UoORieKk2gEb05BR gr+N81Q2qAYBFoBb/8t7zJAMPlWgAVCQU7xLJwqG7888tt/oPphrGBwmWRO5GvMr /OTXqYgc7d3jUQ2LqD6H =xbBp -----END PGP SIGNATURE----- --HditFSw+SJxJh6AP--