From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757790AbaHGNPs (ORCPT ); Thu, 7 Aug 2014 09:15:48 -0400 Received: from casper.infradead.org ([85.118.1.10]:47189 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757399AbaHGNPr (ORCPT ); Thu, 7 Aug 2014 09:15:47 -0400 Date: Thu, 7 Aug 2014 15:15:36 +0200 From: Peter Zijlstra To: Frederic Weisbecker Cc: Dave Jones , Linux Kernel Subject: Re: WARN_ON_ONCE(in_nmi()) hit in irq_work_queue_on Message-ID: <20140807131536.GU9918@twins.programming.kicks-ass.net> References: <20140806162113.GC14261@redhat.com> <20140806164633.GY3935@laptop> <20140806165610.GB12054@laptop.lan> <20140806170151.GC12054@laptop.lan> <20140806234456.GA17015@localhost.localdomain> <20140807081321.GI19379@twins.programming.kicks-ass.net> <20140807125852.GA19662@localhost.localdomain> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="H3rjvnIlNW8PJoxD" Content-Disposition: inline In-Reply-To: <20140807125852.GA19662@localhost.localdomain> 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 --H3rjvnIlNW8PJoxD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 07, 2014 at 02:58:55PM +0200, Frederic Weisbecker wrote: > On Thu, Aug 07, 2014 at 10:13:21AM +0200, Peter Zijlstra wrote: > > On Thu, Aug 07, 2014 at 01:44:58AM +0200, Frederic Weisbecker wrote: > > > In fact the problem has arised since the recent irq work patches I di= d. > >=20 > > No, those just added the WARN, previously we send the resched IPI, and > > that's equally wrong from NMI context. >=20 > Well the scheduler IPI was rather used for remote kicks before we had rem= ote irq > work. This includes local kicks as well as the caller could need to kick > anywhere. As in inc_nr_running(). >=20 > But for strict local kicks, as in perf, we were using tick_nohz_full_kick= () which has > been using irq work for a while. But it got broken when we replaced it to= call irq_work_queue_on > instead of irq_work_queue. OK, clearly I made a mess of things in my head ;-) --H3rjvnIlNW8PJoxD Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJT43v4AAoJEHZH4aRLwOS6VWoP/1fvlo4eWGR4T6N1eWbVXJg6 PxSoivOQTHL+uFzflv5CVoPsUC9PYMbobMQQgn4GOpVAfPTy2w3APWU21vWrzl1M DNOVbVAsSh7Xj4jQjyZ0nPrMMEixVHgVZZUZgyiyt+ohyMj2BVv+vN0uc/LQuvkO pJRriURwP70gGrY6792XNIq3WtgJk15djEooDLNTUGSOsDb7bmzGJ0nvf6VJBrL8 +rr54dLwptRqlt30eFpgyGK/ARMje8jBnvUJivY+ssSHTl4IELVOmrhLukpuQBQr fLGKpsVFcnBjTZlPrzpAIDcEL7eD7yoHhOUzH4/NNVGEQKaUd/IXVO1qTXk7AY17 D2RBEtj/0//wrPi/KEvpR1a5ye96B0FOuuxUbnA4Da79l9puFsoX2YBdLdbAcO1F qLUOU7zM72anulkFaBEgfTpCN8q/lcDCX4LQh5QiO0iz6zbB7/XXIXHOlSOi1ZeK N/EgjR6m6fdCWdFjCEiOkfxBD/9QqmBfhvxYCAPBu/QEtQo4+blNQXePReo8SMF8 vbY3p3xQlQNwiDUBKtT9WvQtCwVu40B3U6wbffkcx549sbE+f990JqhpO9RKDcsI FfkHT9Z8u6/rPj/wKlgVByMq+a2iYcxTgboX6ta+f8n+/IhGR8NBMMy6tMlSvAEg PRZ4imZeb2KCamV3YSlZ =00Qu -----END PGP SIGNATURE----- --H3rjvnIlNW8PJoxD--