From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Laptop shock detection and harddisk protection Date: Fri, 12 Sep 2008 01:35:54 +0200 Message-ID: <48C9AB5A.705@kernel.org> References: <48C7FCEE.8060404@kernel.org> <41840b750809110908o54a61f55w7b1b9793abf55634@mail.gmail.com> <48C948A6.3080404@kernel.org> <41840b750809111325t30f8ffe2sa4572d401d43dc5a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:53076 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754853AbYIKXh1 (ORCPT ); Thu, 11 Sep 2008 19:37:27 -0400 In-Reply-To: <41840b750809111325t30f8ffe2sa4572d401d43dc5a@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Shem Multinymous Cc: Elias Oltmanns , Thomas Renninger , Linux Kernel Mailing List , IDE/ATA development list Shem Multinymous wrote: >> That reduction comes because input device supports poll and >> sysfs_notify_event() does about the same thing. The uesrland daemon >> can just poll on a node and read data nodes when poll event on the >> node triggeres. > > Agreed. > There's another issue with the current sysfs interface, though: hdapsd > needs to read (x,y,timestamp) tuples, whereas sysfs provides just x > and y in separate attributes which cannot be read atomically together. > We can add a sysfs file with "x y timestamp" readouts, though this is > unusual for sysfs (and certainly incompatible with hwmon). Yes, right. Forgot about the atomicity part altogether. Thanks for bringing it up. >> Unloading heads will be simple. Just echoing timeout in ms to sysfs >> nodes, so I don't think it's a good idea to push out actual unloading >> to another process especially as fork doesn't inherit mlockall. > > I had in mind another daemon listening for "unload now" events, so no > forking needed. > This second daemon might make sense if we push the logic of deciding > *which* disks to unload into userspace, since this logic is the same > for the ThinkPad style and the HP style. Hmmm... I can't (yet) see the benefit of having two separate userland daemons. >> On a related note, is there any plan to merge tp_smapi to mainline? >> It seems you put a lot of work into it and I don't really see why it >> should stay out of tree. > > The only issue I'm aware of is finding a reasonably-named maintainer. > On the technical side, the reviews on my lkml submission of > thinkpad_ec+hdaps seemed good and all technical comments are since > addressed. The code has been stable, well-tested and packaged by major > distros for years. Cool, can you please post the patch to the lkml and cc Greg Kroah-Hartman , Andrew Morton and me? Thanks. -- tejun