From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932183AbWGDPCK (ORCPT ); Tue, 4 Jul 2006 11:02:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932184AbWGDPCK (ORCPT ); Tue, 4 Jul 2006 11:02:10 -0400 Received: from wx-out-0102.google.com ([66.249.82.199]:57519 "EHLO wx-out-0102.google.com") by vger.kernel.org with ESMTP id S932183AbWGDPCF (ORCPT ); Tue, 4 Jul 2006 11:02:05 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent:sender; b=b7GI8sIUXr5HgbQZIZPuxakbyIQUgukWfOz60mHrC0FDnAkz/I0BQzCqYD42S8e4ldATc2a0E4++mhYjRHO1R/wyVeOsGO0j5wzXf7lQHqePGujA4P74dVpmsbe8oCI8mxuF7U0ZX0D2WE+DsyLE0vcgVfVg40PRE/5sQRABGLU= Date: Tue, 4 Jul 2006 11:02:05 -0400 From: Thomas Tuttle To: Linux-Kernel Mailing List Subject: Re: [Hdaps-devel] Generic interface for accelerometers (AMS, HDAPS, ...) Message-ID: <20060704150205.GC3611@phoenix> References: <20060703124823.GA18821@khazad-dum.debian.net> <20060704075950.GA13073@elf.ucw.cz> <41840b750607040326y7bfe92dy21c6845ab034ce30@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="NU0Ex4SbNnrxsi6C" Content-Disposition: inline In-Reply-To: <41840b750607040326y7bfe92dy21c6845ab034ce30@mail.gmail.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --NU0Ex4SbNnrxsi6C Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On July 04 at 06:26 EDT, Shem Multinymous hastily scribbled: > Will moving the hdapsd userspace daemon from sysfs polling to the > input infrastructure cause a noticable latency increase compared to > polling sysfs? This functionality is highly time-critical. > > Also, there's a small issue with polling frequency. hdapsd needs a > fairly high frequency (say, 50Hz) to gather statistics and keep > response latency low, whereas the hdaps driver's internal polling > (routing to the input infrastructure) is currently done at only 20Hz. > We'll need to increase the latter, thereby slightly increasing system > load when hdaps isn't running. Just out of curiousity, is there any reason that these hard drive parking schemes *aren't* implemented entirely in the kernel? Wouldn't implementing it in the kernel give it much lower latency? --=20 Thomas Tuttle (thinkinginbinary@gmail.com) Get Thunderbird: Reclaim your inbox. mozilla.org/products/thunderbird aim/y!m:thinkinginbinary; icq:198113263; jabber:thinkinginbinary@jabber.org msn: thinkinginbinary@hotmail.com; pgp: 0xAF5112C6 --NU0Ex4SbNnrxsi6C Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEqoLt/UG6u69REsYRAmtyAJ9Vkj+DBKU40ruUpwgZ0kcWSWm6HQCePsAr N+Pa7Sek1WiAEm3q/gSuUxQ= =Z17I -----END PGP SIGNATURE----- --NU0Ex4SbNnrxsi6C--