Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964874AbWHHMu6 (ORCPT ); Tue, 8 Aug 2006 08:50:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964876AbWHHMu0 (ORCPT ); Tue, 8 Aug 2006 08:50:26 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:36871 "EHLO spitz.ucw.cz") by vger.kernel.org with ESMTP id S932457AbWHHMuO (ORCPT ); Tue, 8 Aug 2006 08:50:14 -0400 Date: Tue, 8 Aug 2006 12:08:39 +0000 From: Pavel Machek To: Shem Multinymous Cc: Robert Love , Jean Delvare , Greg Kroah-Hartman , Alan Cox , linux-kernel@vger.kernel.org, hdaps-devel@lists.sourceforge.net Subject: Re: [PATCH 06/12] hdaps: Limit hardware query rate Message-ID: <20060808120839.GD4540@ucw.cz> References: <11548492171301-git-send-email-multinymous@gmail.com> <1154849268493-git-send-email-multinymous@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1154849268493-git-send-email-multinymous@gmail.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1261 Lines: 30 Hi! > The current hdaps driver queries the hardware on (almost) any sysfs read. > Since fresh readouts are genereated by the hardware at a constant rate, > this means apps are eating each other's events. Also, polling multiple > attributes will genereate excessive hardware queries and excessive CPU > load due to the duration of the hardware query transaction. > > With this patch, the driver will normally update its cached readouts > only in its timer function (which exists anyway, for the input device). > If that read failed, it will be retried upon the actual sysfs access. > In all cases, query rate is bounded and apps will get reasonably > fresh and usually cached readouts. > > The polling rate is increased to 50Hz, as needed by the hdaps daemon. > A later patch makes this configurable. > > Signed-off-by: Shem Multinymous I'd insert fewer blank lines, otherwise patch looks ok to me. Signed-off-by: Pavel Machek -- Thanks for all the (sleeping) penguins. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/