From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754838AbaEOIZR (ORCPT ); Thu, 15 May 2014 04:25:17 -0400 Received: from casper.infradead.org ([85.118.1.10]:56618 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754628AbaEOIZM (ORCPT ); Thu, 15 May 2014 04:25:12 -0400 Date: Thu, 15 May 2014 10:25:07 +0200 From: Peter Zijlstra To: "Carlos O'Donell" Cc: Thomas Gleixner , Darren Hart , LKML , Dave Jones , Linus Torvalds , Darren Hart , Davidlohr Bueso , Ingo Molnar , Steven Rostedt , Clark Williams , Paul McKenney , Lai Jiangshan , Roland McGrath , Jakub Jelinek , Michael Kerrisk , Sebastian Andrzej Siewior Subject: Re: [patch 0/3] futex/rtmutex: Fix issues exposed by trinity Message-ID: <20140515082507.GC30445@twins.programming.kicks-ass.net> References: <20140512190438.314125476@linutronix.de> <20140513035404.GA68181@dvhart-mac01.local> <53731608.3010803@redhat.com> <5373D94E.5030800@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/SlKNoLjL08cymhl" Content-Disposition: inline In-Reply-To: <5373D94E.5030800@redhat.com> 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 --/SlKNoLjL08cymhl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 14, 2014 at 04:59:58PM -0400, Carlos O'Donell wrote: > I will make my personal opinion clear: >=20 > - Internal defects should raise immediate assertions. >=20 > - Real problems like resource availability, deadlocks, and > other recoverable errors should result in the API returning > an appropriate error code that must not diverge from the POSIX > definitions for those codes (when such a definition exists). >=20 > I'm not a believer in "only the hot path matters", there are such > things as robustness and error detection, and they matter. Awesome. In case of doubt though, I would prefer a return to an assert, just in case userspace actually does know wtf its doing ;-) Granted, that seems to be very rare, but still, its entirely annoying for those few people who do care to get dead programs. Alternatively, we could have something like you have for the allocator (which is, afaik, also considered a hot path) these env variables like MALLOC_CHECK_ to influence this edge behaviour. --/SlKNoLjL08cymhl Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTdHnjAAoJEHZH4aRLwOS6QSsP/3YF0Zgr/Gtovu4ybl5oY5kb Z2jjX1XdiE55IDCgahLWECSh7iZyM4JfEcIUUqmYEnofgaKk+4ACecLFD7it8fp4 Xt/ROS43oQpgAKkQ89QQ6xxVLYWYKsyOwU2z1VTmP6H0FgbrodLXBkWif7GcupAl I5qXn8s2VNMtN3VdWlzoxuGr+PkLPXyZWkVKJDzSz1RNsotpphUN8KU6Gl22KIG/ 6udhK0FtrBP3s0wpA00Tqqz7dhJThNU/tfdDvQwjRTb9qzYXGgDDiO74VKBQ4tMv JwdVkETr5xOyQt8o2Eb+3GLmttqfL1H1MMxqc30yyEhBee4b4SQ8ylnV241o0l4o iIIVqpo+YIt7X6gBQ1fEJFCfFURHckV3J7lCU5CDFIeqpHJnR33Un/mmnsvfY7ff s8tH+HUtQGvPQcXmVxw8EFfzp+a5Ga42AyI7FIVokKRTSdd5+36wIjGHUkYyqGWm Qk4Mi1K7DCOmt4OydSsaFqY7cmx+lWrZXPSfetIqvoo3SVoXyJE4kBYyAcIbteev Bqm538RqkrUx6GSC0Du4kh54oQ4mXpl1BD9Fr4AdKXOgQqAKFK4GiMWbNn8T/LNe mtDvc0aBwVrgDzO3JcMMqxgzs4iz10x48qC0Oim5JrcPJ2RWoeTPMdrDq3kr5Qnp wv/gGgy3yn3uI6Vk9Php =Qfxg -----END PGP SIGNATURE----- --/SlKNoLjL08cymhl--