From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261859AbULUVgH (ORCPT ); Tue, 21 Dec 2004 16:36:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261862AbULUVgH (ORCPT ); Tue, 21 Dec 2004 16:36:07 -0500 Received: from mail26.syd.optusnet.com.au ([211.29.133.167]:21638 "EHLO mail26.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S261859AbULUVgB (ORCPT ); Tue, 21 Dec 2004 16:36:01 -0500 Message-ID: <41C89734.8020302@kolivas.org> Date: Wed, 22 Dec 2004 08:35:48 +1100 From: Con Kolivas User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: jesse Cc: Paulo Marques , linux-kernel@vger.kernel.org Subject: Re: Gurus, a silly question for preemptive behavior References: <20041221190339.24215.qmail@web52605.mail.yahoo.com> In-Reply-To: <20041221190339.24215.qmail@web52605.mail.yahoo.com> X-Enigmail-Version: 0.89.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig3391ABC2449B215600E72F01" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig3391ABC2449B215600E72F01 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit jesse wrote: > Paulo: > > I already said in the messsage that my user space > application has a low nice priority, i set it to 10. > since my application has low priority compared to > other user space applications, it is supposed to be > interrupted. but it is not. If your task is better priority the scheduler will make it preempt the worse priority task. It sounds to me like you are complaining that the worse priority task is still getting cpu? If so, you misunderstand priority - it orders tasks according to priority giving lower latency and preemptive behaviour to the better task, and gives _more_ cpu but not all the cpu. The cpu must still be shared, but with more cpu distributed to the better priority task. If you want your better priority task to get _all_ the cpu you have to use real time scheduling. Cheers, Con P.S. Please dont top post when replying, it's hard to follow an email thread to see what you're replying to if you do that. These threads can get very long and confusing. --------------enig3391ABC2449B215600E72F01 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFByJc2ZUg7+tp6mRURAs2EAJ4njSxd3KglBqSXDbReYFRcLiaPiACdEMD7 5igfw4CYCB0qmAKkSbh4wQs= =dP/y -----END PGP SIGNATURE----- --------------enig3391ABC2449B215600E72F01--