From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261854AbVC3MGo (ORCPT ); Wed, 30 Mar 2005 07:06:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261877AbVC3MGo (ORCPT ); Wed, 30 Mar 2005 07:06:44 -0500 Received: from wproxy.gmail.com ([64.233.184.201]:60124 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S261853AbVC3MGk (ORCPT ); Wed, 30 Mar 2005 07:06:40 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:references; b=LKZmqrx4xXotT5xYGDdRnzXyueeL7TfOE+7d+v5aoXbsP8RINBf9B1TsqBHQkIRC9Knq7ELQQYYjfeBpvNzs1i7EuAdrZHLEN6z12gqmz3tV4E43d3Iy9QISaCq6HkHA0Tx2BpF/9p+LGo3S3zpCMMZTpkdubimGS4VZIIXO3zY= Message-ID: <58cb370e05033004065b14da51@mail.gmail.com> Date: Wed, 30 Mar 2005 14:06:37 +0200 From: Bartlomiej Zolnierkiewicz Reply-To: Bartlomiej Zolnierkiewicz To: kus Kusche Klaus Subject: Re: 2.6.11, IDE: Strange scheduling behaviour: high-pri RT process not scheduled? Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit References: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Mar 2005 13:52:05 +0200, kus Kusche Klaus wrote: > However, things break seriously when exercising the CF card in parallel > (e.g. with a dd if=/dev/hda of=/dev/null): > > * The rtc *interrupt handler* is delayed for up to 250 *micro*seconds. > This is very bad for my purpose, but easy to explain: It is roughly the > time needed to transfer 512 Bytes from a CF card which can transfer 2 > Mbyte/sec, and obviously, the CPU blocks all interrupts while making pio > > transfers. (Why? Is this really necessary?) > > (I know because I instrumented the rtc irq handler with rdtscl(), too) hdparm -u1 /dev/hda should help