From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by befuddled.reisers.ca (Postfix, from userid 65534) id E839E1C0D4E; Fri, 22 May 2020 13:13:49 -0400 (EDT) Received: from hera.aquilenet.fr (hera.aquilenet.fr [185.233.100.1]) by befuddled.reisers.ca (Postfix) with ESMTPS id A02911C07F4 for ; Fri, 22 May 2020 13:13:48 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 69A153968; Fri, 22 May 2020 19:13:17 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xn3rcvaificZ; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from function (unknown [IPv6:2a01:cb19:956:1b00:9eb6:d0ff:fe88:c3c7]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 7B3002E76; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from samy by function with local (Exim 4.93) (envelope-from ) id 1jcBEO-00HA74-1l; Fri, 22 May 2020 19:13:12 +0200 Date: Fri, 22 May 2020 19:13:12 +0200 From: Samuel Thibault To: Joe Perches Cc: Dan Carpenter , MugilRaj , devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, Chris Brannon Subject: Re: [PATCH] taging: speakup: remove volatile Message-ID: <20200522171312.s2ciifuxozwav2ym@function> Mail-Followup-To: Samuel Thibault , Joe Perches , Dan Carpenter , MugilRaj , devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, Chris Brannon References: <1590138989-6091-1-git-send-email-dmugil2000@gmail.com> <20200522103406.GK30374@kadam> <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> Organization: I am not organized User-Agent: NeoMutt/20170609 (1.8.3) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 X-BeenThere: speakup@linux-speakup.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Speakup is a screen review system for Linux." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 May 2020 17:13:50 -0000 Joe Perches, le ven. 22 mai 2020 09:36:05 -0700, a ecrit: > On Fri, 2020-05-22 at 13:34 +0300, Dan Carpenter wrote: > > On Fri, May 22, 2020 at 02:46:28PM +0530, MugilRaj wrote: > > > fix checkpatch.pl warning, which is Use of volatile is usually wrong: see > > > Documentation/process/volatile-considered-harmful.rst > > > Signed-off-by: MugilRaj > > > > Please put a blank before the Signed-off-by line. > > > > Probably there should be a space between your first and last name. It's > > supposed to your legal name like for signing a legal document so use > > whatever is appropriate legal documents in your country. > > > > Also the Documentation/process/volatile-considered-harmful.rst explains > > that people often use "volatile" when they should be using locking for > > synchronization. That seems to be the case here. So the correct fix is > > to add locking. That's a little bit complicated to do and requires > > testing. > > > > If we apply this patch, then we have silenced the warning so now someone > > will have to look for the bug. But if we leave it as-is, then everyone > > will know that the code is buggy. So let's leave it as-is until we are > > able to fix the bug. > > > > It's always better to have easy to find bugs, than hidden bugs. > > And better still to comment known opportunities to > improve the code so the next time someone tries to > remove this volatile, there's a comment right there > showing what's necessary instead. Actually I don't think adding the suggestion is a good thing if it's only a "rule-of-thumb-replace-volatile-with-lock". Actually possibly volatile might not even be needed because there could be already a lock protecting this. Put another way: I don't think putting any hint here would help, on the contrary, somebody has to really look at what protection is needed, without getting influenced by rules-of-thumb. Samuel