Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262006AbVDRJTK (ORCPT ); Mon, 18 Apr 2005 05:19:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261904AbVDRJSA (ORCPT ); Mon, 18 Apr 2005 05:18:00 -0400 Received: from omx3-ext.sgi.com ([192.48.171.20]:6791 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S262012AbVDRJQi (ORCPT ); Mon, 18 Apr 2005 05:16:38 -0400 Date: Mon, 18 Apr 2005 02:16:09 -0700 From: Paul Jackson To: Chris Wedgwood Cc: ikebe.takashi@lab.ntt.co.jp, linux-kernel@vger.kernel.org Subject: Re: [PATCH x86_64] Live Patching Function on 2.6.11.7 Message-Id: <20050418021609.07f6ec16.pj@sgi.com> In-Reply-To: <20050418075635.GB644@taniwha.stupidest.org> References: <4263275A.2020405@lab.ntt.co.jp> <20050418040718.GA31163@taniwha.stupidest.org> <4263356D.9080007@lab.ntt.co.jp> <20050418061221.GA32315@taniwha.stupidest.org> <42636285.9060405@lab.ntt.co.jp> <20050418075635.GB644@taniwha.stupidest.org> Organization: SGI X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1748 Lines: 41 Chris wrote: > Linux doesn't guarantee you'll get scheduled > (strictly speaking) in n milliseconds usually. The general case load doesn't apply here. Those doing call switching know what they have running, and know that it won't give the scheduler any opportunities to not run what must be run, in time. Given a sufficiently short run queue, the scheduler is quite predictable. And there is difference between the entire system being down for over 100 milliseconds, and a given call being delayed that long. Under sufficient load (busiest hour on Mothers Day, say), the system must continue to operate, though some switching may be delayed longer than normal, though still within specified limits. > > This function is very essential whenever ... > > Those are just marketing words. > ... > I'm guessing any suggestion of fixing the applications behavior would > be lost with some argument along the lines of ... The call switching folks have been doing live patching at least since I worked on it, over 25 years ago. This is not just marketing. No sense in being disrespectful to Takashi-san. This patch may or may not be the best way to provide the functionality they require. I don't even know if a kernel patch is needed. But the tone of this thread won't lead anyone to better answers anytime soon. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373, 1.925.600.0401 - 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/