Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932247AbZKRVjh (ORCPT ); Wed, 18 Nov 2009 16:39:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757193AbZKRVjg (ORCPT ); Wed, 18 Nov 2009 16:39:36 -0500 Received: from mail-fx0-f221.google.com ([209.85.220.221]:59709 "EHLO mail-fx0-f221.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753197AbZKRVjg (ORCPT ); Wed, 18 Nov 2009 16:39:36 -0500 MIME-Version: 1.0 In-Reply-To: <20091118213526.GB16630@srcf.ucam.org> References: <1258474180.16176.62.camel@localhost.localdomain> <20091118194053.GB12944@srcf.ucam.org> <20091118195342.GA13627@srcf.ucam.org> <20091118200712.GA14026@srcf.ucam.org> <20091118213526.GB16630@srcf.ucam.org> From: Kay Sievers Date: Wed, 18 Nov 2009 22:39:26 +0100 Message-ID: Subject: Re: [PATCH] [RFC] Add support for uevents on block device idle changes To: Matthew Garrett Cc: David Zeuthen , linux-kernel@vger.kernel.org, axboe@kernel.dk, linux-hotplug@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 952 Lines: 21 On Wed, Nov 18, 2009 at 22:35, Matthew Garrett wrote: > On Wed, Nov 18, 2009 at 10:29:23PM +0100, Kay Sievers wrote: > >> I guess, the "idle_since" file could be made poll()able, and throw an >> event when the idle time is re-set to 0, so the value checking needs >> only to happen as long we wait for the disk to become idle. As long as >> it's busy anyway, the rare wakeups should not matter much. :) > > That'd be a userspace wakeup every time something gets submitted to the > block device, which sounds far from ideal... No, you would only poll() when you reached the timeout and the disk entered the idle state. This can not happen more frequently than the timeout itself. Kay -- 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/