From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759622AbXGJF4n (ORCPT ); Tue, 10 Jul 2007 01:56:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751894AbXGJF4g (ORCPT ); Tue, 10 Jul 2007 01:56:36 -0400 Received: from nz-out-0506.google.com ([64.233.162.225]:41043 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751099AbXGJF4f (ORCPT ); Tue, 10 Jul 2007 01:56:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=lDcQeDrQnH38vwb4MaM4MPYgW3QG2744J7DBM2x53/hHfsiQUdgGdw9piT92dOtOxE8njOT050Y6efGv3HciC/ymXcMavnQe/xpmCdTvc0WBpnPQbFqonOFcdMIqC/F1Z8hrDFtMGWFB8fHQSw64cwYhCSGsEinAhemDKxKju9M= Message-ID: <41840b750707092256i280b6f00oac7b25004bf27bea@mail.gmail.com> Date: Tue, 10 Jul 2007 01:56:34 -0400 From: "Shem Multinymous" To: "Dmitry Torokhov" Subject: Re: [Hdaps-devel] [PATCH] hdaps - switch to using input-polldev Cc: hdaps-devel@lists.sourceforge.net, rlove@rlove.org, "Linux Kernel ML" , "Andrew Morton" , "Michael Riepe" , "Henrique de Moraes Holschuh" In-Reply-To: <200707092358.08529.dtor@insightbb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200705252354.43730.dtor@insightbb.com> <200707090144.45557.dtor@insightbb.com> <41840b750707082306n6509ee6ds3a0ccd16b6387353@mail.gmail.com> <200707092358.08529.dtor@insightbb.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 7/9/07, Dmitry Torokhov wrote: > > Sounds good, then. It's a bit of a hack, but the benefits are well > > worth it (if we can resolve the scheduling issue). > > You know, I slept on it and I think I want to move the polldev into > opposite direction - to accomodte devices that need "relaxed" polling > and are ok with polling being a bit irregular and maybe even rounded > to next jiffy or something to better accomodate tickless kernels. How about letting drivers and/or clients explicitly express their scheduling needs, e.g., in terms of a desired polling rate and a desired bound on scheduling irregularity? Given these requirements, input-polldev will try to satisfy all requests (i.e., the harshest one) made by the driver and current clients, on a "best effort" basis, using minimal resources. (There should also be a way for a driver to say "don't bother to poll more often than X or with regularity better than Y even if a client asks for it -- the hardware isn't that fast anyway".) This way the same infrastructure could smoothly handle devices and apps with vastly different polling needs. That doesn't help much with the workqueue vs. timers issue, of course, unless input-polldev implements *both*. Shem