Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754202AbXJHPIQ (ORCPT ); Mon, 8 Oct 2007 11:08:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751972AbXJHPIG (ORCPT ); Mon, 8 Oct 2007 11:08:06 -0400 Received: from www.tglx.de ([62.245.132.106]:59768 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751730AbXJHPIF (ORCPT ); Mon, 8 Oct 2007 11:08:05 -0400 Date: Mon, 8 Oct 2007 17:07:34 +0200 (CEST) From: Thomas Gleixner To: Jaswinder Singh cc: Steven Rostedt , LKML , RT , Ingo Molnar Subject: Re: 2.6.23-rc9-rt2 In-Reply-To: <1985e0f60710080734y4897a8e1ke253b6d4273146ec@mail.gmail.com> Message-ID: References: <1191536413.5210.19.camel@localhost.localdomain> <1985e0f60710070635l7016bad1t9c4d4cb1a966534f@mail.gmail.com> <1985e0f60710080734y4897a8e1ke253b6d4273146ec@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1136 Lines: 28 On Mon, 8 Oct 2007, Jaswinder Singh wrote: > On 10/8/07, Steven Rostedt wrote: > > > > Not sure what you mean by this, since interrupt handlers are run as > > threads and are fully preemptible. > > > I think by nested or reentrant interrupt handling technique you can > further reduce latencies. > what you think. Interrupt handlers in vanilla Linux and preempt-rt are never reentrant. There is no advantage of allowing interrupt handler reentrancy, quite the contrary it makes the code more complex. The interrupt handlers in preempt-rt are running in threads. One thread per interrupt, so depending on the thread priority the handlers a handler of one interrupt can preempt the running handler of another interrupt. > Can we can get guaranteed realtime throughput by using these realtime patch. Realtime is not about throughput. It's about determinism. tglx - 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/