From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759396AbXGJQGF (ORCPT ); Tue, 10 Jul 2007 12:06:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752623AbXGJQFz (ORCPT ); Tue, 10 Jul 2007 12:05:55 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:45021 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753093AbXGJQFy (ORCPT ); Tue, 10 Jul 2007 12:05:54 -0400 Subject: Re: [PATCH] LinuxPPS (with new syscalls API) - new version From: David Woodhouse To: Rodolfo Giometti Cc: linux-kernel@vger.kernel.org, Andrew Morton In-Reply-To: <20070709131924.GM11451@enneenne.com> References: <20070628161450.GD13886@enneenne.com> <1183117082.1170.308.camel@pmac.infradead.org> <20070629150813.GM13886@enneenne.com> <1183132548.1170.360.camel@pmac.infradead.org> <20070629163422.GP13886@enneenne.com> <1183135253.17622.5.camel@shinybook.infradead.org> <20070630171340.GT13886@enneenne.com> <1183291392.2828.17.camel@shinybook.infradead.org> <20070703094831.GA13413@enneenne.com> <1183468191.29081.17.camel@shinybook.infradead.org> <20070709131924.GM11451@enneenne.com> Content-Type: text/plain Date: Tue, 10 Jul 2007 17:05:47 +0100 Message-Id: <1184083547.32628.4.camel@pmac.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.10.2 (2.10.2-2.fc7.dwmw2.1) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2007-07-09 at 15:19 +0200, Rodolfo Giometti wrote: > > > Also read Documentation/volatile-considered-harmful.txt and ponder > > deeply your use of 'volatile' on certain members of struct pps_s. > > I read such document but I'm still convinced that the attribute > volatile is needed for {assert,clear}_sequence and {assert,clear}_tu > since inside pps_event() they are updated without any locks at all > thanks to the dummy_info variable which is used for unallocated PPS > sources. I'm sure the version with 'volatile' will also be broken then. Sounds like the right answer is to fix the locking. -- dwmw2